# 100Ah battery life calculator. 100ah battery life calculator

## Trolling Motor Battery Charts (Run Time Calculator)

With our charts, you can compare the run times of different battery sizes when used with popular trolling motor sizes: 30, 55, 80 and 112 pounds of thrust.

Our battery run time calculator will give you an idea of what you can expect from a given battery capacity at a specific amp draw.

## How Do We Calculate Run Time?

The run time of trolling motor batteries is calculated by dividing the battery’s amp-hours (Ah) rating by the number of amps the motor draws at a given speed.

In our calculations, we assume 80% depth of discharge (DoD), which means the battery will still have 20% remaining capacity. This is a recommended value for lithium batteries.

## Trolling Motor Run Time Calculator

In the battery charts below, we use a rough estimation of how much amp draw occurs at different speeds. The actual amount varies depending on the motor being used, as well as the boat and water conditions.

To get an accurate amp draw estimation, read your motor’s user manual or check our amp draw chart.

Remember to factor in any additional electrical equipment that may be using power from the battery while trolling.

## lb Trolling Motor Battery Chart

Trolling motors with 30 pounds of thrust are often found on smaller boats like kayaks and canoes. They are powered by a single 12-volt battery. The following chart shows the run times at various speeds with different battery sizes.

## lb Trolling Motor Battery Chart

Trolling motors with 80 pounds of thrust are most often found on larger boats such as bass boats, pontoons, and small center console fishing boats. They are powered by two 12 volt batteries wired in series for 24 volts in total.

## 2 lb Trolling Motor Battery Chart

These powerful trolling motors are typically found on larger and heavier boats. They need 36 volts to run at full power. (3 x 12 Volts)

## Depth of Discharge

For lead-acid batteries, the deeper a battery is discharged, the lower its capacity and run time will be. It’s recommended not to discharge them more than 50% to maximize your battery’s life. If you frequently discharge a lead-acid battery to 80%, it will very likely have reduced capacity after one season.

Lithium batteries, on the other hand, can be regularly discharged to 80% and still last hold the charge after 5 and more years.

## Battery Type and Longevity

The main difference between lead-acid and lithium batteries is their longevity. Lead-acid batteries will typically last around two or three years with regular use, while lithium batteries can last five years or more.

Additionally, lead-acid batteries are prone to sulfation (the buildup of sulfate crystals on the plates) when stored for long periods of time, while lithium batteries do not suffer from this problem.

## Battery Warranty

When selecting a trolling motor battery, it’s important to consider the warranty offered by the manufacturer.

Lithium batteries usually come with a longer warranty, often up to five years full coverage and sometimes as much as 10.

## Conclusion

By comparing different batteries on this chart, you can identify the best battery size for your application based on the trolling motor thrust.

Keep in mind the amp draw is just an estimation based on our research to give you a rough idea of what to expect.

### Trolling Motor Shaft Length (Essential Guide)

December 30, 2020

### Garmin Transducer Compatibility Guide (Complete Chart)

August 27, 2022

Hi there, I’m Tom!I am an outdoors, camping and boating enthusiast. My greatest passion is electrical propulsion systems, including trolling motors and electric outboards. I like building things, fixing them and sharing helpful knowledge. About Me

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## HOW LONG DOES A TROLLING MOTOR BATTERY LAST?

Two of the most common questions we receive are “How long will this motor run for?” and “How to calculate how long a battery will last?”. These are common questions because they are very important in understanding how long to stay out on the water before heading back. They are fairly easy to answer if you have all the necessary information, which can be provided by our Smart Battery Box. To determine a battery last and motor runtime, you will need to know the following information: The amperage draw of the motor and the Amp Hour rating on your battery.

## AMP HOUR RATING

Amp Hour (Ah) is a common rating placed on Deep Cycle or Marine batteries. This rating measures how long a battery can maintain a consistent amperage output. easily put, how much charge the battery can hold and how long it can power an electronic device. The larger the rating, the longer it can power a device or trolling motor.

### QUICK NOTES:

• If a battery doesn’t have an Ah rating, you can calculate the Ah rating from the Reserve Capacity (RC). You simply divide the RC by 2.4 to get an estimated amp hour rating.
• For Example:1600 RC / 2.4 = 66.66Ah

## MOTOR AMPERAGE DRAW

Amperage draw describes the amount of electricity the motor pulls from the battery to power itself. A motor pulls different amounts of amps depending on the speed it is operating at and if there is any resistance applied to the motor. This information should be provided by the manufacturer and should be readily available on the product listing or on a specification sheet for the motor. However, only the max amperage draw will typically be listed. this is the amount current the motor pulls from the battery at top speed.

To determine how long a battery will last or how long your motor will run for, we must divide the amp hour rating on the battery against amps drawn by the motor. For example, if we have a deep cycle battery that is rated for 50Ah and we are pairing it with a motor that draws 52 Amps at max speed, we would use the following equation:

50 amp hour / 52 amps drawn =.96 hours of runtime

If the manufacturer only provides Watts drawn by the motor, we can convert this to amps by dividing against the voltage being used. You have to be careful if you are using a 12V, 24V or 36V system as this can affect your calculations. For example, if we have a 50Ah battery and a motor that draws 624 watts at full speed and uses a 12V battery, we would use the following equation:

624 watts draw / 12 volts = 52 amps drawn at top speed 50 Ah / 52 amps drawn =.96 hours of runtime

If we are using a 24V system that draws 1,152 watts with two 50Ah batteries in series (100Ah total), we would use the following equation:

1,152 watts draw / 24 volts = 48 amps drawn at top speed100 Ah / 48 amps drawn = 2.08 hours of runtime

It should be noted that these are only estimates and they do not factor in weight, wind or water resistance or other external factors. While only estimates, these can be very helpful in deciding on the right battery or motor for your application. Below is a chart showing the max amp draw Newport Vessels trolling motors for your reference.

### QUICK NOTES:

• We can estimate amp draw based off the pounds of thrust a trolling motor is rated for by rounding down to the nearest ten.
• For example: 46lbs of thrust roughly draws 40 amps. However, this is only true for 12V powered trolling motors.
• A better estimate of this runtime can be achieved by dividing the max amp draw in half and using that answer in the equation.
• Just as rowing a boat up stream is harder than downstream, when a motor encounters resistance, it will pull more current from the battery to overcome the additional resistance.

### SUMMARY

Calculating battery life is easy with two pieces of information: the battery amp hour rating, and the amount of amps a motor uses.

• The amp hour rating on a battery measures the amount of charge a battery can hold, the larger the number, the longer it can power a motor.

Motors draw different amounts of current from the battery depending on the motor size and speed it is turning. With this information, just divide the amp hour rating on your battery by the amp draw of your motor. This will give you an estimated battery life for your trolling motor.

See our selection of LiFePo4 Lithium Trolling Motor Batteries here.

## Battery Capacity: A Guide to Understanding

Knowing the size of your battery (or battery capacity), is critical if you want to accurately predict what appliances it will be able to power, and for how long. Indeed, this fact is so important that most solar generator manufacturers actually include the capacity rating in the name of their product. For example, you can see that in one of our own products, the Bluetti AC200P/2000Wh. In this article we will discuss what battery capacity is, how to calculate the right capacity for your energy needs, and more.

## What is battery capacity?

Battery capacity is defined as the total amount of electricity generated due to electrochemical reactions in the battery and is expressed in ampere hours (Ah), watt hours (Wh) or kilowatt hours (kWh). Generally, car batteries or vanlife batteries are sold under their charge capacity (Ah) rating while solar generators are sold under their energy capacity rating (Wh). In summary: Watt-hours (Wh) = energy capacity, while ampere-hours (Ah) = charge capacity.

## Why do some batteries have a higher capacity than others?

Batteries come with varying levels of capacity. Generally, the capacity of a battery is determined by the following factors:

### Number and size of plates in a cell

The amount of plates, or their size indicates the total amount of active substance that allows energy to be stored. This means that the battery in question, will have an increased ability to store more or deliver more energy should their be more active ingredient in the battery plates.

### Density of the electrolyte

If manufacturers opt for higher density electrolyte inside a battery, the overall capacity will increase (to some degree). However, with added density, this also equates to shorter battery life. therefore, if higher capacity is what you are after, it is not as simple as increasing the density of the electrolyte. Lastly, the overall capacity of a battery also depends on its age. The more a battery is used, the more you can expect its overall capacity to decrease.

## How do you calculate the capacity of a battery?

Contrary to popular belief, calculating your battery capacity is really not that hard. Let us explain. So, depending on the type/ size battery you buy, you may notice it comes listed in either, mAh, Ah, Wh, or kWh. Generally small powerbanks come listed in mAh (milliampere hour), car batteries in Ah (ampere hours), solar generators in Wh (watt hours) and residential energy storage systems in kWh (kilowatt hour). But how do we convert one unit into another. It’s pretty easy, as long as you have one unit of measurement plus the batteries voltage you can always convert one into the other. Here’s an example:

### Ah To Wh/kWh

Keep in mind though, that just because two batteries have the same charge capacity (Ah) it does not mean they will necessarily have the same energy capacity.

Generally. most household appliances are rated on how much power they require to function. i am sure you have noticed the sticker on the back indicating their power rating in Watts (W = voltage x current).

This is why knowing the energy capacity can be much more useful than knowing the charge capacity, assuming you aim to power household appliances with your battery system.

## Battery capacity vs battery life

It is actually quite common for people to confuse battery capacity with battery life at first.

We recommend knowing the difference before buying any battery as there is actually an incredibly big difference between the two.

### Battery capacity

As we have already mentioned, ba ttery capacity is defined as the total amount of electricity generated due to electrochemical reactions in the battery and is expressed in ampere hours (Ah), watt hours (Wh) or kilowatt hours (kWh). This is the measurement which indicates what your battery will be able to power and for how long.

### Battery life

Battery life on the other hand indicates how many life cycles it has before it starts degrading. The biggest influencing factor here is the battery type/ chemistry.

 Chemistry Shelf Life Cycle Life Alkaline 5-10 Years None Carbon Zinc 3-5 Years None Lithium Non-Rechargeable 10-12 Years None Nickel Cadmium 1.5-3 Years 1,000 Nickel Metal Hydride 3-5 Years 700-1,000 Lithium Rechargeable 2-4 Years 600-1,000 Lead Acid 6 Months Varies, see above LiFePO4 10 years 3500

As you can see cycle life varies greatly. This is why working out your levelized cost of storage (LCOS) is so important when buying a battery.

For example, let’s say you are looking to buy a 100Ah battery.

You are trying to decide between a lead-acid or LiFePO4 battery

To calculate LCOS you need to know the total energy output of the battery and the total upfront cost, along with the batteries DOP.

As you can see, overtime the LiFePO4 battery is roughly 2 times cheaper and lasts 5X as long.

This is why Bluetti only uses LiFePO4 batteries in their latest solar generators.

## Final thoughts

We hope you found this article informative. Remember, when working out your batteries capacity, it is also important to work out its LCOS. By doing this, you will ensure you are getting the best value for money overtime.

Additionally, a batteries charge capacity (Ah) can be converted to energy capacity by simply multiplying its voltage (V) by its nominal capacity (Ah).

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## ﻿Introduction: Electric Bike (Ebike) Range Calculator

One of the most common questions we get is how to calculate the geographic range of an electric bike. Basically,

• How far will my ebike go before it runs out of battery power?
• What is the range of my ebike?
• How far can I go per charge?

There are many factors that affect an electric bike’s range, including the type of bike you’re riding, as well as the battery capacity, terrain, and the level of pedaling effort you as the rider put in.

If you have a Bosch motor system, then you should probably use the Bosch ebike distance calculator. But for all other ebikes, our Range Calculator is the most sophisticated online today.

The truth is that most ebikes come with a Bafang motor system or its equivalent, since they are the largest ebike motor manufacturer in the world, and have an exceptional reputation. Our ebike range calculator has been designed based on the performance of the Bafang electric bike system.

For a more precise estimate of electric bike range, we have developed a detailed ebike range calculator which has 16 Separate Inputs and Over 100 Variants. Try it now, and start keeping track of your actual range to help us refine the system. If you want to learn all the details about how far electric bikes can go, and how to get the most range from your ebike battery, skip the calculator and continue reading the rest of this article.

Average speed for the duration of your ride, including regular pedaling and use of pedal assist and throttle.

Amount of pedal power you supply to reach the average speed. 0 = Throttle Only, 9 = Eco Mode.

• 0 Throttle Only
• 2 Turbo Mode
• 4 Sport Mode
• 6 Tour Mode
• 9 Eco Mode

Total weigh including bike, battery, rider, and any cargo you are carrying on the bike or in a trailer.

• 100 lbs
• 125 lbs
• 150 lbs
• 175 lbs
• 200 lbs
• 225 lbs
• 250 lbs
• 300 lbs
• 325 lbs

On average, how many times do you make one full rotation per minute when pedaling?

• 10 rpm
• 20 rpm
• 30 rpm
• 40 rpm
• 50 rpm
• 60 rpm
• 70 rpm
• 80 rpm
• 90 rpm
• 100 rpm
• 110 rpm
• 120 rpm

Where is the motor located on your electric bike?

NOMINAL MOTOR OUTPUT (Watts)

What is the nominal motor output rating of your ebike? For dual drives, enter the combined total wattage.

What is the voltage of your electric bike system?

BATTERY CAPACITY (Amp-Hours)

What is the capacity of your ebike battery, as measured in Amp-Hours (Ah)?

• 8.0 Ah
• 10.4 Ah
• 11.6 Ah
• 14.0 Ah
• 16.0 Ah
• 20.0 Ah
• 25.0 Ah

What style of electric bike are you riding?

Select the tire tread that most closely resembles that of the tires on your electric bike.

NUMBER OF MECHANICAL GEARS

Select the mechanical gear system on your ebike.

• SINGLE SPEED
• 3-SPEED
• 5-SPEED
• 7-SPEED
• 9-SPEED
• 10-SPEED
• 14-SPEED
• 15-SPEED
• 21-SPEED
• 27-SPEED

Select the mechanical gear system on your ebike.

Select the terrain that best describes the average terrain for your ride.

Select which best describes the suface conditions you will encounter most on your ride.

• SMOOTH ASPHALT
• UNIFORM GRAVEL
• ROUGH GRAVEL / ROCKY
• HEAVILY RUTTED
• SAND OR SNOW

Which best describes the weather conditions you will encounter during your ride?

How often stop completely, and start from a standing position? Level 1 = Rarely, Level 5 = Frequently

• NO STOPS
• A FEW STOPS
• SOME STOPS
• LOTS OF STOPS
• CITY TRAFFIC

## Ebike Battery Myth Busting

First, a little electric bike battery myth busting is in order. Every ebike manufacturer should provide detailed specifications for the battery and every other component on the models they bring to market. Many will also provide estimated ranges, but rarely indicate how these range estimates were derived. That is why we built this calculator, so that you could get a fairly precise range based on your ebike specifications and riding conditions.

Estimated ranges provided by ebike brands aren’t based on rigorous testing

Next, let’s dismiss another obvious falsehood. All ebikes can be ridden like conventional bikes, simply by pedaling and using the standard gears. If the electric vehicle you’re looking at does not have operable pedals, it’s not an electric bike.

If you ride your ebike with the electronics turned off, there is no loss of battery charge. And if you ride your ebike without turning on electronics, there is no drag or resistance from the turned-off ebike motor.

There is no drag or resistance from the turned-off motor

That being said, ebikes do tend to be heavier than standard bikes, due to the added weight of the motor, battery and controller. But there are also lightweight ebikes that fold up and are highly portable.

The lithium-ion battery is the fuel tank for your ebike, not unlike the batteries that power your cell phone and laptop computer. In the olden days a few years ago, some legacy ebike brands would use sealed lead acid (SLA) batteries on their ebikes.

You can still find these types of batteries in cars and on mobility scooters. But with improvements in battery technology, the denser and more energy efficient lithium-ion battery has been adopted as the standard for all ebikes. These batteries will vary in their chemistry, as well as their operating voltage and capacity. Do not get a bike that does not have a lithium battery pack. Find out more about electric bike batteries at our Ebike Battery FAQ.

Like the lithium batteries powering your personal electronic devices, ebike batteries will not last forever. After about 1,000 charge cycles, you will notice that the battery is not holding a full charge. For the average rider, it takes about 2-4 years to charge and discharge an ebike battery 1,000 times. These timeframes could be greatly reduced if you expose your electric bike battery to extremes in heat or cold. So it’s best not to leave your battery in the trunk of a hot car, or in a garage that might reach freezing temperatures overnight.

When you finally need to get a new battery for your ebike, have no fear. Usually replacement or spare batteries are available from the original manufacturer, but even if they are not, there are reputable 3rd party battery companies that can provide a high-quality replacement. Our go-to favorite company for this is the Ebike Marketplace in Las Vegas.

## Non-Electrical Factors that Affect Electric Bike Range

There are many variables that affect ebike range, including the bike design of bike, rider weight and riding style, terrain, weather, surface moisture, tire inflation.

Bike Design Maintenance. Electric bikes, like conventional bikes, come in many flavors. You have fat tire mountain ebikes, small folding ebikes, and laid back cruiser style ebikes. There are several key factors in bike design that affect range.

First, the weight of the bike is a major factor, but also the width of the tires. Fat tires, for example, have more surface area in contact with the ground, and more traction (friction) compared to a road bike with narrower tires. This adds resistance which can deplete energy reserves more quickly.

Second, it’s important to note that a poorly tuned or maintained ebike will have a shorter range than a properly maintained vehicle. Low tire inflation, poorly aligned gears and brakes, and high wind resistance due to a lack of aerodynamic design will all contribute to reducing the range of an ebike.

Payload. The weight of the passenger and any cargo will also have a dramatic effect on ebike range. All things being equal, a 225-pound rider with a fully-loaded trailer will place a much higher demand on the battery than a 125-pound teenager with a fanny pack. The distribution of the payload on the bike will also affect range, especially if a bike is unbalanced due to heavy loads placed on the rear rack.

Weather Terrain. Headwinds and wet roads each will reduce the potential range of an ebike. Likewise, how hilly your ride is, and if you go off-road on gravelly trails will impact how far you can travel on a single charge.

## Electrical Factors that Affect Ebike Range

All electric bikes have 3 essential components that set them apart from conventional bikes. These are the motor, the controller and the battery. Each of these electrical components plays a critical role in the performance of an electrical bike, and if any of them are not working properly, it can adversely affect your ebike performance range.

If you struggle with the concept of electrons running through wires to power a motor, you’re not alone. Check out the Water Pipe Analogy graphic below.

We use watt-hours to measure the energy capacity of a battery pack, and this will help you figure out how long you can ride your ebike before fully discharging the battery. But before we get into watt-hours (symbolized Wh), let’s first review what a watt itself is.

A watt (W) is a unit of power, and power is the rate at which energy is produced or consumed. Think of watts as a measure of electrical flow. Does an electrical device need a big flow or a small flow to work? For example, a 100W light bulb uses energy at a higher rate than a 60W bulb; this means that the 100W light bulb needs a bigger “flow” to work. Likewise, the rate at which your solar energy system “flows” power into your home is measured in watts.

A watt-hour (Wh) is a unit of energy equivalent to one watt (1W) of power expended for one hour (1h) of time. A watt-hour is a way to measure the amount of work performed or generated. Household appliances and other electrical devices perform “work” and that requires energy in the form of electricity. Utilities typically charge you for electrical energy by the kilowatt-hour (kWh), which is equal to 1,000 watt-hours.

An ebike battery is measured by its voltage (V) and amp-hour (Ah) rating. To calculate the Wh of an ebike battery pack, we simply multiply its V and Ah to get the Wh.

• A battery rated at 36 V and 10.4 Ah will have a 417.6 Wh capacity (36 x 10.4 = 374.4), like on the Eunorau UHVO All-Terrain Ebike
• A battery rated at 48 V and 21 Ah will have a 1,008 Wh capacity (48 x 21 = 1,008), like on the Bakcou Mule.

To learn more about ebike batteries beyond simply their range potential, check out our Ebike Battery FAQ. And if you want another expert’s opinion about ebike range, check out Micah Toll at Electrek.

## Volt, Amps, Amp-hour, Watt and Watt-hour: terminology and guide

We understand that all this terminology can be a bit confusing at times but once you know how it works it is quite simple. Below we will try to explain what it all means.

### Volt or Voltage (V):

The number of volts is the amount of energy given to an electronic circuit. By a circuit we mean, for example, an electronic device. With a 12V device, 12 volts are always “given” from the battery. A battery always has a fixed voltage (e.g. 12, 24, or 36 volts) and a device always works at a certain voltage. For example, a device that works on 12 volts obviously needs a battery that also supplies 12V.

### Current – Ampere (A):

When we talk about amperes (or amps), we are talking about how much electricity “flows” per second. If the number of amps goes up, then current flowing through the device per second also goes up. An electrical device usually works on a fixed voltage, but the amount of amps it draws can vary depending on, for example, the position of your trolling engine (a trolling engine at full throttle draws more amps than in half throttle for instance).

Example 1: Suppose I have a Minn Kota Endura C2 50 LBS that I am running on gear / speed setting 2. The trolling engine runs on 12V and currently draws 15A. I decide to go a little faster and I switch to gear / speed setting 4. The engine still runs on 12V but now pulls 25A. The voltage has remained the same but the number of amps has gone up.

### Power – Watts (W): :

Power is the voltage multiplied by the number of amps, or W = V x A. This is the amount of energy consumed by a device and therefore an indication of how powerful it is. This goes up when the number of amps also goes up.

Example 2: Suppose I have a 24V Minn Kota Terrova 80 LBS bow motor that draws 30 amps. So the power consumption is 24 x 30 = 720W.

Example 3: Suppose I have another Minn Kota Endura C2 50 LBS that I am running in gear / speed setting 2. The engine runs on 12V and draws 15A and thus has a power consumption of 180W (12 x 15). When I switch to gear / speed setting 4, the engine draws 25A and still runs on 12V. The power consumption of the trolling motor is now 300W.

### Capacity – Amp hours (Ah):

Battery capacity is measured in Ah, or Amp-hours. As the name suggests this means how many amps the battery can deliver in an hour. For example, a 12V lithium battery with a capacity of 100Ah can deliver 100A to a 12-volt device for one hour. The same 100Ah battery could supply power for 4 hours (100/25=4) to a 25 ampere device. If a battery has 12V50, this means that the battery works on 12 Volt and has a capacity of 50Ah. A 24V100 battery works on 24 Volt with a capacity of 100 Ah etc. In practice for lead-acid batteries the nominal capacity (how many Amps hours the battery can deliver according to specifications) differs greatly from the effective capacity (how many Amps the battery can actually deliver during use). We explain how this works in our article discharge and battery capacity.

Example 4: I run my Minn Kota Endura C2 50 LBS in gear / speed setting 2, drawing 15A at 12V. I have a 12 volt battery of 70 ah. My total run time is now 70 / 15 = 4.7 hours. When I switch to gear / speed setting 4 the engine draws 25A. My total runtime is now 70 / 25 = 2.8 hours.

### Capacity – Watt-hour (Wh):

Another way to measure the capacity of the battery is in Watt-hours (Wh). Wh is calculated by multiplying the number of Amps with the battery voltage. For example, a 12V100 (a 12 volt battery with a capacity of 100Ah) has a capacity of 12 x 100 = 1200Wh. A 24V50Ah battery has a capacity of 24 x 50 = 1200Wh. So these batteries have the same capacity, only one works on 12 volts and the other on 24 volts. In practice you will notice that these batteries will be around the same dimensions and weight.

Example 5: I have a 600W trolling motor and a battery with a capacity of 1200Wh. My runtime at full throttle is 2 hours with this battery (1200 / 600 = 2). I do not even need to know how the trolling engine or battery voltage to calculate this (as long as they work at the same voltage obviously).

The attentive reader notes that the runtime of a battery with a device can be calculated in two ways. Either by dividing the number of Amps of the battery by the power draw in A of the trolling motor or by dividing the number of Wh of the battery Wh by the number of W of the trolling engine.

### Connecting batteries: in series and parallel

Batteries can be connected together to achieve a higher voltage or higher capacity. This is done by connecting the battery terminals of the batteries with cables.

Connecting in series: higher voltage, equal number of Ah

When we say that we connect batteries in series, we connect the plus terminal of one battery to the minus terminal of another battery. This means that you still have a minus terminal available on one battery and a plus terminal available on the other battery. The electrical device should be connected to these two available battery terminals. If we connect batteries in series, the voltage goes up, and the capacity measured in Ah remains the same.

In the picture above we see two 12V50Ah batteries. As you can see the two batteries are connected in series: the minus and plus terminals are connected together. You have created a 24V50 battery : 24V (due to series connection) with 50Ah capacity (number of Amps remains the same). If we measure the capacity in Watt-hours, the total capacity is now 24 x 50 = 1200 Wh.

Connecting in Parallel: equal voltage, higher number of Amps

When connecting batteries in parallel, we connect the minus terminal of one battery to the minus terminal of the other battery and the plus terminal of one battery to the plus terminal of the other battery. We connect the minus wire of the electrical appliance to one of the minus terminals and the plus wire to the plus terminal of the other battery (see the picture below). The same voltage is now supplied but the number of Amps has increased.

In the picture above, the minus terminals of both batteries are connected and the plus terminals are connected. So the battery is connected in parallel. There is still 12 Volt but the number of Amps has increased from 50 to 100. We have now created a 12V100Ah battery. If we measure the capacity in Watt-hours, the total capacity is now 12 x 100 = 1200 Wh.

So the number of watt-hours always remains the same, whether you connect them in series or parallel.

Attention: always check whether batteries are suitable to connect together. Only connect identical batteries (same type/model, age and charge status) and use cables of the correct thickness and length. We recommend that you do not connect 12 volt Rebelcell batteries in series but instead select a Rebelcell 24 volt battery. Rebelcell 24 volt batteries can be connected in series up to 48V without any problems.

### Other terminology relating to batteries

The technical specification for batteries often includes many other terms. Below we will try explain what the most important ones mean.

Voltage: this is the voltage that the battery delivers on average. As explained above, the battery starts with a higher voltage than when it is partially discharged. With this we mean the average of this progression or the nominal voltage.

Chemistry: this indicates what kind of lithium battery technology is used.

C1, C5, C20: this indicates battery capacity when discharged in a certain number of hours. C20= 100Ah means that the battery can deliver 100 ampere hours if it is discharged in 20 hours (with 5A). Lead batteries have a lower capacity if they are discharged faster. For example, a lead-acid battery can deliver 100Ah if it is discharged in 20 hours (C20=100), but if the same battery is discharged in 5 hours it will only deliver 70Ah (C5=70). With Rebelcell batteries it doesn’t matter if you discharge them in 20 hours, 5 hours or 1 hour, they always deliver the same capacity. That is why we always refer to our capacity as Capacity (C1-C20). Read more about this in our article about effective battery capacity.

EqPb: this stands for ‘equivalent lead battery’. By this we mean that this battery can be compared to a lead battery with the indicated capacity when used in combination with an electric motor. Often a lithium battery with a much lower Ah can in practice deliver the same amount as a lead-acid battery with a much higher Ah. In practice, for example, the Rebelcell 12V50 can be compared to a 105Ah semi-traction battery in terms of operating time for an electric motor. This also has everything to do with the usable battery capacity.

Nominal energy: this is the battery capacity measured in watt-hours (see above for explanation).

Maximum continuous discharge: this is the maximum number of amps the battery can continuously deliver. Suppose a battery has a maximum continuous discharge of 30A, then you cannot connect a device that draws more than 30A. The higher the capacity of the battery, the higher the maximum continuous discharge.

Peak discharge (10 milli-sec): this is the maximum number of amps the battery can deliver for 10 milli-seconds. This is always higher than the maximum continuous discharge. Some equipment has a short peak discharge when starting up (so called ‘inrush’ currents). This is for example the case when you go from zero to full throttle in one go with an electric outboard engine. At that moment, the motor requires more amps than the rated maximum for a short time.

Lifespan (#charges) (@80%DoD): this indicates how often you can discharge and recharge the battery up to a certain percentage. For example, if it says “Lifetime (#charges) (@80%DoD): 1500” it means that the battery can be discharged to 80% for 1500 times (i.e. with 20% capacity left). For example, if it says “Lifetime (#charges) (@100%DoD): 1000” then the battery can be fully discharged 1000 times.

Energy density: with this we measure the number of Watt-hours per kilo of battery. Energy density is much higher for lithium batteries than for lead-acid batteries. A high energy density means that you can store more energy in the same space. And this results in a lighter and smaller battery.

Bandwidth voltage: see explanation of the discharge and capacity of batteries. This gives the minimum voltage (at 0%) and the maximum voltage (at 100%) of the battery.

Charge temperature: this gives the minimum and maximum temperature at which a battery can be charged.

Discharge temperature: this indicates the minimum and maximum temperature at which a battery can be discharged.

Storage temperature: This indicates the minimum and maximum temperature at which a battery can be stored safely.

Maximum charge current: This gives the maximum current in A at which the battery can be charged. The higher this number, the faster the battery can be charged (with the right battery charger).

Integrated cell balancing: part of the Battery Management System. The cell balancing feature ensures that the voltage of individual lithium battery cells is equalised, so the cells all have the same charge status / voltage. This is necessary for optimal use and performance of the battery.

Temperature protection: part of the Battery Management System. The battery is switched off when the temperature becomes too high or too low. This is a protection to prevent damage.

Maximum discharge current protection: part of the Battery Management System. The battery is switched off when the power draw of your equipment is higher than is allowed. This is a protection to prevent damage.

Overvoltage protection: part of the Battery Management System. The battery is switched off when the voltage becomes too high and the battery is overcharged. This is a protection to prevent damage.