# 2S LiPo/Lion Battery Charger Using Micro USB 5V/2A Power Supply. 5v battery charger

## Battery Charge Time Calculator

Use our battery charge time calculator to easily estimate how long it’ll take to fully charge your battery.

## Battery Charge Time Calculator

Tip: If you’re solar charging your battery, you can estimate its charge time much more accurately with our solar battery charge time calculator.

### How to Use This Calculator

Enter your battery capacity and select its units from the list. The unit options are milliamp hours (mAh), amp hours (Ah), watt hours (Wh), and kilowatt hours (kWh).

Enter your battery charger’s charge current and select its units from the list. The unit options are milliamps (mA), amps (A), and watts (W).

If the calculator asks for it, enter your battery voltage or charge voltage. Depending on the combination of units you selected for your battery capacity and charge current, the calculator may ask you to input a voltage.

Select your battery type from the list.

Optional: Enter your battery state of charge as a percentage. For instance, if your battery is 20% charged, you’d enter the number 20. If your battery is dead, you’d enter 0.

Click Calculate Charge Time to get your results.

## Battery Charging Time Calculation Formulas

For those interested in the underlying math, here are 3 formulas to for calculating battery charging time. I start with the simplest and least accurate formula and end with the most complex but most accurate.

### Formula 1

Formula: charge time = battery capacity ÷ charge current

Accuracy: Lowest

Complexity: Lowest

The easiest but least accurate way to estimate charge time is to divide battery capacity by charge current.

Most often, your battery’s capacity will be given in amp hours (Ah), and your charger’s charge current will be given in amps (A). So you’ll often see this formula written with these units:

charge time = battery capacity (Ah) ÷ charge current (A)

However, battery capacity can also be expressed in milliamp hours (mAh), watt hours (Wh) and kilowatt hours (kWh). And your battery charger may tell you its power output in milliamps (mA) or watts (W) rather than amps. So you may also see the formula written with different unit combinations.

charge time = battery capacity (mAh) ÷ charge current (mA) charge time = battery capacity (Wh) ÷ charge rate (W)

And sometimes, your units are mismatched. Your battery capacity may be given in watt hours and your charge rate in amps. Or they may be given in milliamp hours and watts.

In these cases, you need to convert the units until you have a ‘matching’ pair.- such as amp hours and amps, watt hours and watts, or milliamp hours and milliamps.

For reference, here are the formulas you need to convert between the most common units for battery capacity and charge rate. Most of them link to our relevant conversion calculator.

Battery capacity unit conversions:

• watt hours = amp hours × volts
• amp hours = watt hours ÷ volts
• milliamp hours = amp hours × 1000
• amp hours = milliamp hours ÷ 1000
• watt hours = milliamp hours × volts ÷ 1000
• milliamp hours = watt hours ÷ volts × 1000
• kilowatt hours = amp hours × volts ÷ 1000
• amp hours = kilowatt hours ÷ volts × 1000
• watt hours = kilowatt hours × 1000
• kilowatt hours = watt hours ÷ 1000

Charge rate unit conversions:

The formula itself is simple, but taking into account all the possible conversions can get a little overwhelming. So let’s run through a few examples.

### Example 1: Battery Capacity in Amp Hours, Charging Current in Amps

Let’s say you have the following setup:

• Battery capacity: 100 amp hours
• Charging current: 10 amps

To calculate charging time using this formula, you simply divide battery capacity by charging current.

In this scenario, your estimated charge time is 10 hours.

### Example 2: Battery Capacity in Watt Hours, Charging Rate in Watts

Let’s now consider this scenario:

Because your units are again ‘matching’, to calculate charging time you again simply divide battery capacity by charging rate.

In this scenario, your estimated charge time is 8 hours.

### Example 3: Battery Capacity in Milliamp Hours, Charging Rate in Watts

Let’s consider the following scenario where the units are mismatched.

First, you need to decide which set of matching units you want to convert to. You consider watt hours for battery capacity and watts for charge rate. But you’re unable to find the battery’s voltage, which you need to convert milliamp hours to watt hours.

You know the charger’s output voltage is 5 volts, so you settle on amp hours for battery capacity and amps for charge rate.

With that decided, you first divide watts by volts to get your charging current in amps.

Next, you convert battery capacity from milliamp hours to amp hours by dividing milliamp hours by 1000.

Now you have your battery capacity and charging current in ‘matching’ units. Finally, you divide battery capacity by charging current to get charge time.

In this example, your estimated battery charging time is 1.5 hours.

### Formula 2

Formula: charge time = battery capacity ÷ (charge current × charge efficiency)

Accuracy: Medium

Complexity: Medium

No battery charges and discharges with 100% efficiency. Some of the energy will be lost due to inefficiencies during the charging process.

This formula builds on the previous one by factoring in charge/discharge efficiency, which differs based on battery type.

Here are efficiency ranges of the main types of rechargeable batteries (source):

Note: Real-world charge efficiency is not fixed and varies throughout the charging process based on a number of factors, including charge rate and battery state of charge. The faster the charge, typically the less efficient it is.

### Example 1: Lead Acid Battery

Let’s assume you have the following setup:

To calculate charging time using Formula 2, first you must pick a charge efficiency value for your battery. Lead acid batteries typically have energy efficiencies of around 80-85%. You’re charging your battery at 0.1C rate, which isn’t that fast, so you assume the efficiency will be around 85%.

With an efficiency percentage picked, you just need to plug the values in to the formula.

100Ah ÷ (10A × 85%) = 100Ah ÷ 8.5A = 11.76 hrs

In this example, your estimated charge time is 11.76 hours.

Recall, that, using Formula 1, we estimated the charge time for this setup to be 10 hours. Just by taking into account charge efficiency our time estimate increased by nearly 2 hours.

### Example 2: LiFePO4 Battery

Let’s assume you again have the following setup:

Based on your battery being a lithium battery and the charge rate being relatively slow, you assume a charge efficiency of 95%. With that, you can plug your values into Formula 2.

1200Wh ÷ (150W × 95%) = 1200Wh ÷ 142.5W = 8.42 hrs

In this example, your estimated charge time is 8.42 hours.

Using Formula 1, we estimated this same setup to have a charge time of 8 hours. Because lithium batteries are more efficient, factoring in charge efficiency doesn’t affect our estimate as much as it did with a lead acid battery.

### Example 3: Lithium Ion Battery

Again, let’s revisit the same setup as before:

First, you need to assume a charge efficiency. Based on the battery being a lithium battery and the charge rate being relatively fast, you assume the charge efficiency is 90%.

As before, you need to ‘match’ units, so you first convert the charging current to amps.

Then you convert the battery’s capacity from milliamp hours to amp hours.

With similar units, you can now plug everything into the formula to calculate charge time.

3Ah ÷ (2A × 90%) = 3Ah ÷ 1.8A = 1.67 hours

In this example, your estimated charge time is 1.67 hours.

### Formula 3

Formula: charge time = (battery capacity × depth of discharge) ÷ (charge current × charge efficiency)

Accuracy: Highest

Complexity: Highest

The 2 formulas above assume that your battery is completely dead. In technical terms, this is expressed by saying the battery is at 100% depth of discharge (DoD). You can also describe it as 0% state of charge (SoC).

Formula 3 incorporates DoD to let you estimate charging time regardless of how charged your battery is.

### Example 1: 50% DoD

Let’s revisit this setup, but this time assume our lead acid battery has a 50% DoD. (Most lead acid batteries should only be discharged to 50% at most to preserve battery life.)

As before, let’s assume a charging efficiency of 85%.

We have all the info we need, so we just plug the numbers into Formula 3.

(100Ah × 50%) ÷ (10A × 85%) = 50Ah ÷ 8.5A = 5.88 hrs

In this example, your battery’s estimated charge time is 5.88 hours.

### Example 2: 80% DoD

For this example, imagine you have the following setup:

As before, we’ll assume that the charging efficiency is 95%.

With that in mind, here’s the calculation you’d do to calculate charge time.

(1200Wh × 80%) ÷ (150W × 95%) = 960Wh ÷ 142.5W = 6.74 hrs

In this example, it will take about 6.7 hours to fully charge your battery from 80% DoD.

### Example 3: 95% DoD

Let’s say your phone battery is at 5%, meaning it’s at a 95% depth of discharge. And your phone battery and charger have the following specs:

As before, we need to convert capacity and charge rate to similar units. Let’s first convert battery capacity to amp hours.

Next, let’s convert charge current to amps.

Because the charge C-rate is relatively high, we’ll again assume a charging efficiency of 90% and then plug everything into Formula 3.

(3Ah × 95%) ÷ (2A × 90%) = 2.85Ah ÷ 1.8A = 1.58 hrs

Your phone battery will take about 1.6 hours to charge from 5% to full.

### Why None of These Formulas Is Perfectly Accurate

None of these battery charge time formulas captures the real-life complexity of battery charging. Here are some more factors that affect charging time:

• Your battery may be powering something. If it is, some of the charge current will be siphoned off to continue powering that device. The more power the device is using, the longer it will take for your battery to charge fully.
• Battery chargers aren’t always outputting their max charge rate. Many battery chargers employ charging algorithms that adjust the charging current and voltage based on how charged the battery is. For example, some battery chargers slow the charge rate down drastically once the battery reaches around 70-80% charged. These charging algorithms vary based on charger and battery type.
• Batteries lose capacity as they age. An older battery will have less capacity than an identical new battery. Your 100Ah LiFePO4 battery may have only have around 85Ah capacity after 1000 cycles. And the rates at which batteries age depend on a number of factors.
• Lithium batteries have a Battery Management System (BMS). Besides consuming a modest amount of power, the BMS can adjust the charging current to protect the battery and optimize its lifespan. iPhones have a feature called Optimized Battery Charging that delays charging the phone’s battery past 80% until you need to use it.
• Lead acid battery chargers usually have a timed absorption stage. After being charged to around 70-80%, many lead acid battery chargers (and solar charge controllers) enter a timed absorption stage for the remainder of the charge cycle that is necessary for the health of the battery. It’s usually a fixed 2-3 hours, regardless of how big your battery is, or how fast your charger.

In short, batteries are wildly complex, and accurately calculating battery charge time is no easy task. It goes without saying that any charge time you calculate using the above formulas.- or our battery charge time calculator.- should be viewed as an estimate.

## Introduction: 2S LiPo/Lion Battery Charger Using Micro USB 5V/2A Power Supply

Introduction: This project will demonstrate an alternative process to charge 2 Lion cells simultaneously using two TP4056 1S battery charger while the output voltage (7.4 V) can be obtained as required. Usually, to charge Lion cells like the 18650 cells in series you either have use a 2S Lion charger which often requires a 12 V or a 9V dc power supply. However, I found it ridiculous to take out the cells and charge them and put it back in the project which in my case is an RC transmitter which I use it to fly planes, quad and more.

This project uses the TP4056, which is a low-cost single-cell Lion charger. It has built-in battery protection and is powered by 5V from a micro USB port. You might use 2 of these chargers to charge each cell separately from two different power sources but, you still have to take the cells out and charge them simultaneously which I still find annoying.

In this project, I will show you how you can charge the 2 cells (7.4V) using a mobile phone’s 5V, 2A power supply without having to remove them every time for charging. Also there is no need to carry a separate dc power supply for charging the 2 cells. No boost converter or 2S Lithium charger is required. Simply plug in the USB cable and slide a switch when you want to charge. Remove the USB and slide back when you want to draw power (@ 7.4V).

## Step 1: Making the Charge/load Toggle Switch

In order to understand how the switch works and why it needs a little modification, refer to the circuit diagram in the next step. Or if you are in a hurry just follow the instructions and understand later. This switch will toggle the charge mode when you want to charge while disconnecting the load simultaneously and vice versa when the battery is gets charged and you want to apply the load.

Important: Each sliding switch should have 2 rows with 3 pins on each side. there are many types of sliding switch. make sure the two rows of pins of the are not internally connected.

At first, align the two switches and apply some super glue. Be careful not to add too much glue or else it may get inside the switch and make it useless. Alternately you may clamp it in a vice while it is nicely aligned.

using the drill make a through-hole through both the switches. Use a small piece od wood between the space and secure with super glue

Inset the screw through the hole and tighten it. Now both the switches should slide all together

## Step 2: Circuit Diagram

You may solder the connections to the battery directly(Non-removable) or use a 4 pin male-female header to make the battery removable.

Depending on your type of application, keep the necessary wire length and solder all connections.

The circuit is a simple arrangement of 2 sliding-type switches which simultaneously switches OFF switch no. A,B and switches ON (CD) for charging or loading as shown in in the figure.

The switches are shown separately in the figure and numbered 1-8. Just solder the respective pins according to the numbering.

Depending on your application choose appropriate lengths of the wire accordingly.

The power supply can directly be applied to either of the USB ports of the TP4056 or else use a micro USB breakout board(Optional) to mount the power inlet elsewhere

## Step 3: Testing

Now connect the 5V from the supply and toggle the switch to charge mode. The red lights should indicate the charging in progress. When the batteries get charged, the light changes to blue.

Toggle the switch and check if the charging has stopped and the power is available at the output.

## Be the First to Share

Did you make this project? Share it with us!

## Комментарии и мнения владельцев

Excelente publicación muchas gracias.Era lo que estaba buscando para el control de un carro de control remoto.Muchas Gracias,

Thanks for posting your first instructable. I hope you enjoyed the process of documenting and sharing your work !

## EBL Lithium Battery Charger with 1.5V AA AAA Li-ion Batteries

### WHAT ARE EBL’S SHIPPING OPTIONS?

Each order from EBL is shipped from the United States and will be delivered by standard shipping with an estimated delivery time of 7-14 business days.

### When will my order be shipped?

We usually take 2 to 5 business days to schedule shipments, except for pre-sales items. A notification will be sent to the customer via email after shipment.

### Which countries do you ship to?

We can ship to the United States, Canada and Mexico.

### Do you ship internationally on your website? Can you ship to my country?

Our website is still testing shipping products worldwide. Therefore, the shipping cost charged at checkout is an estimate and will be based on the actual postage cost incurred when the product is sent by courier (generally based on the weight and volume of the products).Please Note: We will refund the excess if the postage charged is more than the actual shipping charge. Meanwhile, if the postage charged is less than the actual shipping cost, we will also charge the customer for the additional shipping cost.

### Domestic Shipping

Orders over 25

Orders under 25

Standard shipping charge of 5

Weight Between 1-4oz

Weight Between 5-15oz

Weight Between 16-25oz

Weight Between 26-49oz

Weight Between 50-80oz

Delivery areas within the U.S.

EBL official website supports delivery to most areas of the United States. We cannot deliver to the following areas:

• American Samoa
• Guam
• Marshall Islands
• Northern Mariana Islands
• Palau
• U.S. Virgin Islands
• Armed Forces Americas
• Armed Forces Europe
• Armed Forces Pacific

Please note: Power stations and solar panels cannot be shipped to Hawaii, Puerto Rico or Alaska.

### International Shipping

We also offer international shipping to the following countries: Canada and Mexico.

As we are still testing shipping of EBL products to all parts of the world. Therefore, the shipping charges charged at checkout are an estimate and the actual shipping charges will be based on the actual postage costs incurred when the product is sent by the courier (generally based on the weight and volume of the product).

• Batteries cannot be shipped to other countries.
• If the postage charged is more than the actual postage cost, we will refund the excess. Also, if the postage charged is less than the actual shipping cost, we will charge the customer for the additional shipping cost.

### Notes:

1) Standard Shipping is not available for P.O. Boxes and APO/FPO addresses.

2) After the order has been paid, the warehouse needs 2-5 business days to process your order. You will receive a notification once your order has been shipped.

3) If you place more than one order, you may get multiple deliveries. We’ll send you a shipping confirmation email for each order, so you’ll know exactly what to expect and when to expect it.

4) In most cases, the package will be delivered within the estimated time of arrival. However, the actual delivery date may be affected by weather conditions and other external factors. Please refer to the tracking information for the most accurate delivery date.

5) If there is any shipping issue with your package, you must contact Customer Support within 30 days of placing your order.

### How would EBL Official ship my order?

USPS and UPS are our logistics partners to ship out EBL products. we will choose the carrier that we think works best for our customers.

### How do I check the status of my order?

Once your order is picked up by the carrier at our warehouse, we will send you a shipment tracking update email with the estimated delivery date and tracking number. If you do not receive this email, please check your spam or junk mail folder or contact us by email at support@eblofficial.com.

### I ordered more than one item. Will they all be delivered at the same time?

We try to make sure all your items reach you at the same time. Sometimes our products are not always sent together since different shipping options can be used,depending on the product. Once an item has been shipped,you will receive a shipment notification email.

### Why is there no tracking update?

If your order is still under the estimated delivery time frame, kindly wait patiently. Once this process has been completed, you will see tracking updates.

If your order has not been updated for a long time and is overdue, you may contact the shipping courier or contact us for help.

### Can I change the delivery address of my package after it has been shipped out?

Unfortunately, we cannot change the shipping address once the product is in transit.

### What do I need to do when the product I received is different from the one I ordered?

Please provide some details about the issue and contact customer support at support@eblofficial.com.

Welcome to EBL’s Warranty and Refund Policy page, where you can email us directly if you encounter any quality-related problems after purchasing EBL products. We apologize in advance for any inconvenience your purchase of EBL products may cause.

We will take care of all quality-related issues and offer a REPLACEMENT or FULL REFUND, including the return shipping costs.

Please note that this page is for products purchased through eblofficial.com. For products purchased through the EBL store on sites such as eBay and Amazon or from EBL’s authorized distributors, please contact them directly.

## Warranty Period

All products purchased from EBL are guaranteed with a 12-month hassle-free warranty. In each case, the warranty period is measured starting on the date of purchase by the original consumer purchaser.

### Valid Proof of Purchase

A sales receipt from the consumer’s first purchase, or other reasonable proof, is required in order to confirm the start date of the warranty period. Please provide both of the following vouchers when processing warranty claims:

• Provided order number from eblofficial.com.
• The email or phone number or name used to place the order.

### Limited to Original Consumer Buyer

The warranty on EBL’s product is limited to the original consumer purchaser and is not transferable to any subsequent owner.

### Warranty excludes :

• Products without sufficient proof of purchase.
• Damage caused by misuse the faulty parts.(including static discharge).
• Improper installation.
• Damaged by yourself.
• Purchase the product by mistake.
• Neglect, accident or modification, which have been soldered or altered during assembly.
• Complimentary products.

### Exchange

EBL will replace any EBL product that fails to operate within the applicable warranty period due to defect in workmanship or material. The replacement product assumes the remaining warranty period of the original product.

## Refund

We offer a 30 day hassle-free money back guarantee on items purchased directly from eblofficial.com. ( We only provide prepaid return label for quality problem products. Other than that, customers need to pay for the return shipping fee. ) If for any reason you are not satisfied and would like to return an item, please let us know within 30 days.

Refunds can only be issued to the original payment method and cannot be issued to other cards or bank accounts. Refunds will be processed within 3-5 business days, and refunds generally take 10-15 business days to be returned to the original payment method.

Note: Once the package is shipped, any shipping costs paid at the time of the order, if applicable, are non-refundable.

There are certain situations where only partial refunds are granted:

• Products with missing parts that do not affect normal use.
• Products that cannot be replaced and have quality problems in part.

Return shipping costs should be paid by the customer in the following situations:

• Purchase the product by mistake.
• Usage of product contrary to its stated instructions.
• Returning products without any proven defect.
• Removal of identification labels such as, but not limited to, the original label, patent, serial number, or trade dress.
• Damage caused by improper storage, abuse or user error.
• Neglect, accident or modification, which have been soldered or altered during assembly.

### How do I return an item?

• Get in touch with us and start the return process within 30 days of the original shipping date.
• Provide proof of purchase from eblofficial.com (either the email address, phone number used to register, or order number).
• The product should be returned in its original packaging, unused, and in the same condition as the item you received.
• Refunds will be processed within 3-5 business days after we confirm receipt of your returned items at our warehouse.

## EBL Smart Lithium Battery Charger for 1.5V AA AAA Li-ion Batteries

### WHAT ARE EBL’S SHIPPING OPTIONS?

Each order from EBL is shipped from the United States and will be delivered by standard shipping with an estimated delivery time of 7-14 business days.

### When will my order be shipped?

We usually take 2 to 5 business days to schedule shipments, except for pre-sales items. A notification will be sent to the customer via email after shipment.

### Which countries do you ship to?

We can ship to the United States, Canada and Mexico.

### Do you ship internationally on your website? Can you ship to my country?

Our website is still testing shipping products worldwide. Therefore, the shipping cost charged at checkout is an estimate and will be based on the actual postage cost incurred when the product is sent by courier (generally based on the weight and volume of the products).Please Note: We will refund the excess if the postage charged is more than the actual shipping charge. Meanwhile, if the postage charged is less than the actual shipping cost, we will also charge the customer for the additional shipping cost.

### Domestic Shipping

Orders over 25

Orders under 25

Standard shipping charge of 5

Weight Between 1-4oz

Weight Between 5-15oz

Weight Between 16-25oz

Weight Between 26-49oz

Weight Between 50-80oz

Delivery areas within the U.S.

EBL official website supports delivery to most areas of the United States. We cannot deliver to the following areas:

• American Samoa
• Guam
• Marshall Islands
• Northern Mariana Islands
• Palau
• U.S. Virgin Islands
• Armed Forces Americas
• Armed Forces Europe
• Armed Forces Pacific

Please note: Power stations and solar panels cannot be shipped to Hawaii, Puerto Rico or Alaska.

### International Shipping

We also offer international shipping to the following countries: Canada and Mexico.

As we are still testing shipping of EBL products to all parts of the world. Therefore, the shipping charges charged at checkout are an estimate and the actual shipping charges will be based on the actual postage costs incurred when the product is sent by the courier (generally based on the weight and volume of the product).

• Batteries cannot be shipped to other countries.
• If the postage charged is more than the actual postage cost, we will refund the excess. Also, if the postage charged is less than the actual shipping cost, we will charge the customer for the additional shipping cost.

### Notes:

1) Standard Shipping is not available for P.O. Boxes and APO/FPO addresses.

2) After the order has been paid, the warehouse needs 2-5 business days to process your order. You will receive a notification once your order has been shipped.

3) If you place more than one order, you may get multiple deliveries. We’ll send you a shipping confirmation email for each order, so you’ll know exactly what to expect and when to expect it.

4) In most cases, the package will be delivered within the estimated time of arrival. However, the actual delivery date may be affected by weather conditions and other external factors. Please refer to the tracking information for the most accurate delivery date.

5) If there is any shipping issue with your package, you must contact Customer Support within 30 days of placing your order.

### How would EBL Official ship my order?

USPS and UPS are our logistics partners to ship out EBL products. we will choose the carrier that we think works best for our customers.

### How do I check the status of my order?

Once your order is picked up by the carrier at our warehouse, we will send you a shipment tracking update email with the estimated delivery date and tracking number. If you do not receive this email, please check your spam or junk mail folder or contact us by email at support@eblofficial.com.

### I ordered more than one item. Will they all be delivered at the same time?

We try to make sure all your items reach you at the same time. Sometimes our products are not always sent together since different shipping options can be used,depending on the product. Once an item has been shipped,you will receive a shipment notification email.

### Why is there no tracking update?

If your order is still under the estimated delivery time frame, kindly wait patiently. Once this process has been completed, you will see tracking updates.

If your order has not been updated for a long time and is overdue, you may contact the shipping courier or contact us for help.

### Can I change the delivery address of my package after it has been shipped out?

Unfortunately, we cannot change the shipping address once the product is in transit.

### What do I need to do when the product I received is different from the one I ordered?

Please provide some details about the issue and contact customer support at support@eblofficial.com.

Welcome to EBL’s Warranty and Refund Policy page, where you can email us directly if you encounter any quality-related problems after purchasing EBL products. We apologize in advance for any inconvenience your purchase of EBL products may cause.

We will take care of all quality-related issues and offer a REPLACEMENT or FULL REFUND, including the return shipping costs.

Please note that this page is for products purchased through eblofficial.com. For products purchased through the EBL store on sites such as eBay and Amazon or from EBL’s authorized distributors, please contact them directly.

## Warranty Period

All products purchased from EBL are guaranteed with a 12-month hassle-free warranty. In each case, the warranty period is measured starting on the date of purchase by the original consumer purchaser.

### Valid Proof of Purchase

A sales receipt from the consumer’s first purchase, or other reasonable proof, is required in order to confirm the start date of the warranty period. Please provide both of the following vouchers when processing warranty claims:

• Provided order number from eblofficial.com.
• The email or phone number or name used to place the order.

### Limited to Original Consumer Buyer

The warranty on EBL’s product is limited to the original consumer purchaser and is not transferable to any subsequent owner.

### Warranty excludes :

• Products without sufficient proof of purchase.
• Damage caused by misuse the faulty parts.(including static discharge).
• Improper installation.
• Damaged by yourself.
• Purchase the product by mistake.
• Neglect, accident or modification, which have been soldered or altered during assembly.
• Complimentary products.

### Exchange

EBL will replace any EBL product that fails to operate within the applicable warranty period due to defect in workmanship or material. The replacement product assumes the remaining warranty period of the original product.

## Refund

We offer a 30 day hassle-free money back guarantee on items purchased directly from eblofficial.com. ( We only provide prepaid return label for quality problem products. Other than that, customers need to pay for the return shipping fee. ) If for any reason you are not satisfied and would like to return an item, please let us know within 30 days.

Refunds can only be issued to the original payment method and cannot be issued to other cards or bank accounts. Refunds will be processed within 3-5 business days, and refunds generally take 10-15 business days to be returned to the original payment method.

Note: Once the package is shipped, any shipping costs paid at the time of the order, if applicable, are non-refundable.

There are certain situations where only partial refunds are granted:

• Products with missing parts that do not affect normal use.
• Products that cannot be replaced and have quality problems in part.

Return shipping costs should be paid by the customer in the following situations:

• Purchase the product by mistake.
• Usage of product contrary to its stated instructions.
• Returning products without any proven defect.
• Removal of identification labels such as, but not limited to, the original label, patent, serial number, or trade dress.
• Damage caused by improper storage, abuse or user error.
• Neglect, accident or modification, which have been soldered or altered during assembly.

### How do I return an item?

• Get in touch with us and start the return process within 30 days of the original shipping date.
• Provide proof of purchase from eblofficial.com (either the email address, phone number used to register, or order number).
• The product should be returned in its original packaging, unused, and in the same condition as the item you received.
• Refunds will be processed within 3-5 business days after we confirm receipt of your returned items at our warehouse.

## SparkFun LiPo Charger/Booster. 5V/1A

×

×

×

×

×

Creative Commons images are CC BY 2.0

## SparkFun LiPo Charger/Booster. 5V/1A

The SparkFun 5V/1A LiPo Charger/Booster is a no-nonsense circuit for generating one amp from a Lithium Polymer battery at 5V. This LiPo charger is a very economical choice that is equipped with a simple booster circuit utilizing the PAM2401 IC, and includes protection diodes so you can run multiple cells in series for an extra kick. While the booster circuit is in operation, this board can draw more current the lower the input voltage, making it perfect to deliver a strong charge in a small amount of time.

The circuit is constructed by feeding an MCP73831 charge controller IC to the LiPo port, and to the input of a PAM2401 boost controller. Multiple connection types are provided for the battery, charge source and switch to allow flexibility of application, and two LEDs provide feedback on system status. If you need more than 5V out of your project, the SparkFun LiPo Charger/Boosters can also be daisy-chained together to get a bigger bang for your buck.

Note: This is not a direct replacement for the SparkFun Power Cell, as it uses a different IC. Also, this board does not possess any undervoltage or other battery protection features, so we do recommend that you use it only with batteries with a built-in protection circuit.

• Charger, microUSB, 500mA
• Booster, 5V, 1A output
• Form factor for our 1,000mAh batteries
• Battery isolation switch with optional external connections
• Enable pin broken out
• Disabled current less than 10uA
• LED indicators for power and charge
• Super-clean output signal (high-frequency switching)

### February 23, 2023

Monitor your LiPo battery with the LiPo fuel gauge! In this tutorial, we will be using the MAX17043 and MAX17048 to monitor a single cell, LiPo battery over the Arduino Serial Monitor. We will also connect a display to view the output without the need to connect the microcontroller to a computer.

### Core Skill: Soldering

This skill defines how difficult the soldering is on a particular product. It might be a couple simple solder joints, or require special reflow tools.

Skill Level: Noob. Some basic soldering is required, but it is limited to a just a few pins, basic through-hole soldering, and couple (if any) polarized components. A basic soldering iron is all you should need. See all skill levels

### Core Skill: Electrical Prototyping

If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.

Skill Level: Competent. You will be required to reference a datasheet or schematic to know how to use a component. Your knowledge of a datasheet will only require basic features like power requirements, pinouts, or communications type. Also, you may need a power supply that?s greater than 12V or more than 1A worth of current. See all skill levels

## Комментарии и мнения владельцев

### Looking for answers to technical questions?

We welcome your Комментарии и мнения владельцев and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

I have tested 3 different PCBs with 3 different 10Ahr batteries, all providing a nominal 3.7-3.9V. I have been charging them with 1.2-2A USB wall chargers for most of the day. The charging LED has yet to turn off, but maybe they haven’t reached full charge, yet. As soon as I disconnect the micro-USB charger all LEDs turn off and I loose the 5V line. When the battery switch is in the ON position (no charger), the battery terminals sag to 0.5V and no 5V line from the booster (giving 10mV). With the battery switch in the OFF position, I read the nominal 3.8V on the Li-ion battery pack, and expectedly nothing else is powered. I have tried charging for 6 hours in both the ON and OFF battery switch positions, and still am not getting 5V out once the charger is disconnected. Is there something I am missing? I can power a circuit directly off of the batteries, so I know there is juice. I need the charging and management circuit though, as well as the 5V switcher line.

Hello!! I was using this circuit and everything was working fine. I tested this board by removing the battery and just by connecting through USB cable. A this moment, it is able to make 5v (which was expected), but, when I’m connecting this 5v to any load, the led stop glowing and there is no output at 5v output terminal. So, this board is working only when the battery is connected and we are using a USB cable to charge that but why its not working when we are powering it through USB cable( without the battery connection) and connecting it to the load?? When there is no battery, still we are getting voltage from USB which boost IC is converting to 5v. So, whats the difference when we are powering it through USB or LIPO battery?

Hi there, it sounds like you are looking for technical assistance. Please use the link in the banner above or the steps in the troubleshooting section, to get started with posting a topic in our forums.Our technical support team will do their best to assist you. That being said, my guess is that the charge that you are pulling is getting supplemented by the battery. Therefore, when you disconnect the battery the USB connection alone (through the charge circuit) can’t provide the current draw you need.

Hello! I would like to add a load sharing circuit to this board in order to use a LiPo battery as a backup battery. I’ve found this load sharing circuit. Do you see any problems in adding the load sharing circuit (Q1, D1 and R2 in my diagram) before the VIN pin of PAM2401? So that when USB power is applied the VIN pin of PAM2401 will be VUSB. VD1 (drop over D1) and when USB power is off the VIN pin of PAM2401 will be VBAT. VSD (drop over Q1). In both cases, my output (PAM2401 output) would be regulated to 5V. Is that correct? Thanks!

I have a question about this board. While charging a lipo does the board automatically disconnect the arduino from the lipo and power it off of the external power? I’ve heard that you shouldn’t charge a lipo while it is powering a device.

Chris is correct. Pulling the enable pin low disconnects the load from the battery.- I can’t remember now but it draws something in the order of microamps during disable. Alternately, I’ve found that minimal loads (10mA) will still allow the battery cycle to complete. So if you can put your device to sleep or disable all of its peripherals, that’s probably good enough.

I just read through the getting started guide and from that my understanding is no. There are two options for turning power to the battery off: the battery switch and the en pin. Hoping to bump this up as it would be great for the designer to answer the question. I’d like to use this in a simple circuit that can be plugged in to charge. What I’m trying to figure out, as you are, is do we need to instruct the end user to power off the device before charging, or can they simply plug it in? Even more specifically: i have a 1Ah LiPo, this, an Esp8266, and a small haptic motor. I’d like to package it up and let people re-charge it. Is that safe? Or, should I turn breakout the battery switch, and have people turn it off before plugging in to charge?

This is a pretty basic circuit, I’ve found that projects I make have a variety of needs so I have to get a bit creative depending on how I want the circuit to operate. If you want the load to automatically be disconnected, use a small N type mosfet to pull the enable pin low with the gate connected to the USB in rail through a resistor. If you require the load to stay active (and can tolerate a 0.5v drop) do the above but also put a pair of schottky diodes ORing the USB rail and the output rail to your load. That way the system will redirect power through the supply while pulling the booster offline. If there’s too much of a gap in power, build an RC filter on the gate to delay the disconnection. One project I built has a button wired to turn on the system (microcontroller) when held, and the microcontroller can then power itself off. So in this instance I simply shut the device down before charging. See this Enginursday. Thanks for the bump

So what is going to happen if I am providing power to the charger over USB while simultaneously drawing 1A from the PAM?

I recently bought this charger and a 1000mAh battery. I charged it with no issues, then used in my setup it until it stopped sending power. I plugged in a micro USB cable to charge it for 48hrs, and the charge light remained on the whole time. When I plugged it back into my setup, it died within 10 minutes. Do you know what might be going wrong? I noticed that there’s some damage to one of the circuit components: https://imgur.com/s4vPu0P Could this be causing an issue?

I realized that I got the Ext SW switch and the Enable pin mixed up. I was trying to charge with the battery disconnected! Seems to be working now.

Sounds great! Sorry if it was confusing. As for that inductor, it shouldn’t be chipped like that but it probably won’t effect operation.- if the whole top comes off then maybe. It’s part of the boost circuit anyway. If it fails you’ll have poor (or no) current output capacity but the charger will still work. Good luck with your project!

Greetings, I was checking out the PAM2401 spec sheet, and the chip puts out a maximum of 3.0A at 5.0V, if I am not mistaken. The current limit is set by the external resistor, on pin #6 of the chip. If the pin is left floating (which apparently it is on your board, but maybe I cannot see the trace), then the current limit is 3.0A. So I’m wondering why don’t you call this a 5-V/3-A charger booster? At any rate, I could use the 3.0A, so if you would kindly point out this resistor R3 so I may remove it, I would be much obliged!

Good question. While the PAM has current limiting capacity through that resistor, the current limiting factor here is actually the inductor (as well as the source’s current capacity). Let’s say the thing is 100% efficient, 5W out = 5W in. If the output is delivering 1A at 5V, that’s 5W power output. If the input is at 2.5V, and 5W is required going in, it needs 2A of input current. The winding of the inductor has resistance which can get in the way of the operation at high currents. See more including some graphs in the hookup guide connecting a load section. All boosters have this property the lower the input voltage, the higher the input current. I designed this such that it can deliver 1A over the entire input voltage range of a LiPo. I actually took my measurements up to 1.3A on the output, but I’d rather provide something with a healthy margin that to call it a 1.3A booster.

Thanks for the fast reply MT, on a holiday no less. The graphs are indeed revealing. I don’t know enough about switch-mode regulators to understand fully, but I can appreciate Power In = Power Out (at 100% efficiency). It’s nice to know that there is some (substantial) margin above 1A output current. In my application, I am driving LEDs, a motor, and a fairly high wattage camera, so I will have to be careful about coordinating these things. If I had the 3A output, I would not have to worry nearly as much. Thanks again.

I’m using this board to light up 12 LEDs, and even with the charger connected, when I load the circuit the LEDs light up for one second, then turn off. Unfortunately I don’t have a multimeter to measure the current, but is this a symptom of an overloaded circuit? What could be going wrong? After this happens, it won’t turn on for a while until I charge it, but is connected to a 1000mAh battery, which I don’t think is empty

Above it says includes protection diodes so you can run multiple cells in series for an extra kick. This is misleading and should say multiple charger/boost boards in series instead of cells. The PAM2401 datasheet shows a max input voltage of 4.75V, which is less than 2 lipo cells in series. And the MCP73831 doesn’t look like it will charge cells in series. Running cells in series would likely kill the board.

is this available for higher voltage like 6 or 7v? If not are there any solutions for 6v battery charging?

Meh. Still waiting for a 2-3S Lipo board with 2-5A output at 5V. As mentioned the Adafruit board has been out for a while now and 1A is old news. I have plenty of applications for a 2a board that something like this can’t be used for. Find me a budget all-in-one 20.25 board for 2-5A and I’m in.

Would I be able to shut down the charging circuit using a microcontroller when the temperature gets below freezing, without turning off the load? Or does the charging IC do that automatically? According to a brief reading into the datasheet it appears to not have this functionality, unless there’s something I’m missing.

That’s kind of an interesting problem, you want to continue to boost but not charge, all while leaving the charger connected. There’s no shutdown pin on the charger IC. I would investigate using a mosfet to switch the charger in and out of the circuit.

Looking for an easy way to adjust the output voltage, although it is not as straightforward as the LiPower. I tried changing R4 to 688k and 488k just to see if I could get the divider to alter the output, but the output voltage remained the same at 5.1. Is the inductor critical in reducing the boost? I can’t say the datasheet or application notes are very helpful. I am looking for something in the 3.6-4.2V range so I don’t have to use another stage of regulator.

The booster is regulating to 0.6V on the feedback pin (FB). Adjust the voltage divider made by R1 and R4 using 0.6 and your desired output voltage as constraints, and it should be OK. I solved R4=600k (with R1=100k) for 4.2V output. maybe there’s something else going on here. The inductor value is not critical to regulation voltage. Also, R4 is stuffed with 750K from the factory so I’m not sure what’s up. I’ll let you know if I discover anything. Keep in mind you can’t buck down from a larger battery voltage! The PAM2401 only boosts.

I replaced R4 with a 680k and I’m getting 3.6 volts. Shouldn’t I be getting higher than the 4.2 you calculated? Am I doing something wrong?

Thanks for the reply. For the record, I am boosting from a 3.0V lithium primary source. I was completely stumped this morning, so I downloaded the Eagle files. Just noticed that there is an identical 750k (R2) that I thought was R4. Whoops.- wrong resistor! Perhaps R2 isn’t too important.since that tiny 750k is long gone anyway. It might be helpful to spin future versions of this board with silkscreen, or at least the voltage divider labeled. I am loving the 1A boost capability of this chip, excited to see it in action.

Nice product. I can see lots of places I could use it. A couple of questions about the design. I noticed 2 22uF caps on the output. Is this because 22uF was deemed not sufficient? And by using 3 22uF caps you get a better volume discount than on 1 22uF and 1 47uF? Also, what is the purpose of the 2 schottky diodes on the output? I get why one (to chain chargers) but why 2?

Thanks! My main concern when designing this was to make sure the voltage was very noise-free on the output. I can’t stand supplies that whine! With that in mind, output capacitance required is a based on the transient load characteristics, which I don’t have any control over. a single 22uF may have been fine, but two is better here! And yes, I was considering that less specific components on the board means less work to build, even if it’s only a single reel in a machine. The diodes allow the boards to be used in series.- see the hookup guide for more info. If one goes dead in a chain, the current will be passed by.

## Customer Reviews

### Great little circuit

about 3 years ago by Member #1614611 verified purchaser

Works as advertised. One comment: Reading the description I expected the enable pin would disable the boost, but I found it disables all output. Re-reading the spec, that is what it says. Thus there apparently is no way to disable boost.

### It delivers on it’s promises

about a month ago by Member #583789 verified purchaser

The small size is perfect for a small battery box I built as an alternative to the 4-AA battery power source for a portable sky tracker for astrophotography. The combination of charging and boosting as well as a battery disconnect switch capability without snipping battery leads is a dream come true for small hobby builds. And the red Power On LED is night-vision friendly.

Note that the math to calculate your battery capacity might not be simple for your load. This circuit will bend over backwards to meet the power needs of the load in spite of a falling input voltage, which means that the current draw from the battery will increase as time goes on. The worthy LiPo batteries include a low voltage cutoff function to avoid damage by being over drawn. My tracker draws a consistent 50 mA and I was able to get just 16 hours of operation from a 1400 mAH LiPo battery. The simplistic math is 1400/50 = 28 hours. So it would be best to test your project if you need to rely on it for a long running session, and maybe consider selecting a larger battery than the simple math would suggest.

I’m giving it 4 stars: starting with 5 for doing exactly what it says, then taking off 1 for the unavoidable realities of physics that aren’t Sparkfun’s fault.