Group 35 Batteries. Dimensions, Features, and Recommendations
BCI Group 35 batteries are very popular battery size of lead-acid batteries, commonly used in cars, trucks, RVs, and other similar applications as starting or dual-purpose batteries.
These batteries, especially dual-purpose and deep cycle batteries, are often used in other applications as well, like UPS batteries, wheelchair batteries, security system backup batteries, medical applications, off-the-grid, etc.
The most popular BCI Group 35 batteries are Absorbent Glass Mat (AGM) Sealed Lead Acid (SLA) batteries, but lithium iron phosphate (LiFePO4) batteries are slowly entering the market, especially for dual-purpose applications.
Updated: January 9, 2023.
Group 35 batteries are medium size batteries featuring 20h capacity in the 42-65 Ah range, providing 430-850 Cold Cranking Amps (CCA), 90-130 minutes Reserve Capacity, etc.
Their physical dimensions are approximately (LxWxH) 9 1/16 x 6 7/8 x 8 7/8 inches (9.0625 x 6.875 x 8.875 inches, 230 x 175 x 225 mm), while their electrical features depending on the battery design, intended use, chemistry, etc.
Group 35 Batteries Comparison Chart
The following chart lists the most popular group 35 batteries, with their most important features (batteries are ordered alphabetically):
Battery Type
Battery Chemistry
Weight (lbs/kg)
Note: Amazon links in the table open in the new Windows (‘Model’ column), feel free to check them for the most up-to-date and offers.
Group 35 Batteries Dimensions, Weight, Chemistry, Features
Again, the physical dimensions of Group 35 batteries are approximately (LxWxH) 9 1/16 x 6 7/8 x 8 7/8 inches (9.0625 x 6.875 x 8.875 inches, 230 x 175 x 225 mm). we have to emphasize this since many group 35 batteries are slightly longer than standard maximum length.
This difference is not large. some of the batteries are less than half of an inch longer than they should be, but since they are intended mostly for cars and similar applications with some room to spare around the battery, they can easily fit such battery compartments.
Nonetheless, be sure to measure the battery compartment first and check that the battery may fit such battery compartment even if it is somewhat larger than the recommended standard.
Most group 35 batteries are spill-proof AGM batteries, designed either as dual-purpose or as starting batteries.
Some of the models are declared as dual-purpose batteries, but in essence, they are starting batteries with increased tolerance toward cycling applications, which is very important for modern vehicles where the main battery has to provide large currents in order to start the main engine (gas, diesel), but also it has to be able to power different electric and electronic systems while the engine is turned off, like audio systems, ventilators, lights, security systems, etc.
Lead-acid group 35 batteries are mostly dual-purpose AGM batteries, featuring strong starting currents, but thanks to improvements in AGM battery technology, they can also cycle well, at least when compared with wet/flooded lead-acid batteries.
AGM lead-acid batteries are spill-proof, maintenance-free batteries that are heavier than lithium batteries, and they don’t cycle as well as lithium batteries.
But, AGM group 35 batteries are very reliable batteries and can operate even in very low temperatures.
Lithium-ion batteries are present in the form of Lithium Iron Phosphate (LiFePO4) batteries, which is practically the safest lithium battery chemistry type.
Lithium-ion batteries feature Battery Management Systems (BMS) that monitor battery parameters, and if necessary, they protect the battery by cutting it off from the rest of the electric circuit. they offer over-voltage, over-charge, over-current, over-discharge, high- and low-temperature protection, and they also often balance individual cells.
Such Battery Management Systems ensure that lithium-ion batteries may be used as drop-in replacements for AGM SLA batteries.
Considering their weight, lithium-ion batteries, as starting batteries, easily outperform AGM batteries with ease.
Note: Lithium batteries are sensitive to low temperatures, and in such conditions, their BMS can simply disconnect the battery from the car’s electric system. Something like that can never happen to AGM lead-acid batteries.
Here are our short reviews of the most popular AGM and lithium group 35 batteries (batteries are ordered alphabetically):
Arc-Angel Group 35 LiFePO4 Battery
Arc-Angel Group 35 LiFePO4 Battery is a true starting/cranking battery with a CCA value of 900 Amps.
Its physical dimensions are 9.37×6.77×8.70 inches (238x172x221), so it is slightly longer than the ‘standard’ group 35 battery.
But, it weighs only 16 pounds (15.99 pounds according to the manufacturer), which is half of the Optima 8020-164 35 RedTop AGM starting battery and less than one-third of the Odyssey 35-PC1400T and NorthStar NSB-AGM35.
Arc-Angel Group 35 LiFePO4 Battery is designed as a drop-in replacement for group 35 AGM/Gel-Cell/Wet lead-acid batteries and may be charged with onboard alternators.
However, it is recommended by the manufacturer to charge it, if possible, with lithium-ion battery chargers. Its nominal capacity is 40 Ah.
It is a maintenance-free battery, with an extra-low self-discharge rate. it is claimed by the manufacturer that it is able to start the car even after one year of storage.
Since these batteries are not very long on the market, at least not when being compared with AGMs, reviews from other users are not very numerous, although the battery itself is often praised by the users.
Arc-Angel Group 35 LiFePO4 Battery comes with a 10-year(!) warranty.
For the most up-to-date offers and prices, feel free to check the Arc-Angel Group 35 Amazon link (the link opens in the new window).
Bosch S6523B S6 Flat Plate AGM Battery
The Bosch S6523B AGM group 35 battery is a robust and reliable battery designed for good performances in both low and high temperatures.
It accepts charge well, allowing it to be used in vehicles with Start/Stop systems. Also, it is recommended for vehicles with short driving distances since it recharges rather quickly after cranking the engine.
Bosch S6523B AGM group 35 battery weighs ~40 pounds (~18.1 kg), it features 53Ah 20h capacity, Reserve Capacity of 110 minutes, 650 Amps CCA rating, and 780 Amps MCA rating.
It is a very good starting battery that cycles well and comes with a 4-year free replacement/pro-rata warranty.
For the most up-to-date offers and prices, feel free to check the Bosch S6523B AGM Group 35 Battery Amazon link (the link opens in the new window).
Delphi BU9035 AGM Group 35 Battery
Delphi BU9035 AGM Group 35 Battery is described as a dual-purpose battery, but it is starting battery with improved tolerance toward deep discharge and cycle applications.
This is a very balanced design, offering 680 CCA, 100 minutes RC, and 50 Ah 20h capacity, all packaged in not too heavy 40 lbs battery.
Also, considering its performance, it is also a reasonably priced battery.
The physical dimensions of the Delphi BU9035 AGM Group 35 Battery are Height: 7.75, Width: 6.75, and Length: 9.563 inches. it is also slightly longer than the ‘standard’ group 35 battery.
For the most up-to-date offers and prices, feel free to check the Delphi BU9035 AGM Group 35 Battery Amazon link (the link opens in the new window).
DieHard 38275 AGM Group 35 Battery
DieHard 38275 AGM Group 35 Battery is very similar to Delphi BU9035 in terms of performance: 650 CCA, 100 minutes RC, and 50 Ah 20h capacity.
Also, it weighs a very acceptable 42 pounds.
As an AGM battery, DieHard 38275 is a spill-proof, maintenance-free group 35 battery with increased vibration resistance and improved tolerance to cyclic and deep discharge applications.
Nonetheless, it performs best as starting battery in gas and diesel cars, trucks, and other vehicles that are not overburdened by multimedia devices and other similar electronics.
For the most up-to-date offers and prices, feel free to check the DieHard 38275 AGM Group 35 Battery Amazon link (the link opens in the new window).
NorthStar NSB-AGM35 AGM Group 35 Battery
NorthStar NSB-AGM35 is a true ‘heavyweight’ among the group 35 batteries, and it weighs 49 pounds, just one pound less than the Odyssey 35-PC1400T battery.
But, NorthStar NSB-AGM35 is also an excellent performer, featuring 60 Ah capacity, 740 CCA, 880 MCA, and 115 minutes RC. it is the only dual-purpose battery that comes close to the Odyssey group 35 battery in terms of performance.
NorthStar NSB-AGM35 physical dimensions are (LxWxH) 9.45×6.76×8.54 inches. another slightly longer than the ‘standard’ group 35 battery.
NorthStar NSB-AGM35 uses plates made of pure lead, ensuring good starting features and deep cycle applications. the battery is able to cycle over 900x when being discharged down to 50% DoD (Depth of Discharge).
Price? Well, what you pay is what you get. an excellent and reliable battery with a very nice price tag.
For the most up-to-date offers and prices, feel free to check the NorthStar NSB-AGM35 AGM Group 35 Battery Amazon link (link opens in the new window).
Optima Batteries 8020-164 35 RedTop Starting Battery
Optima 8020-164 RedTop is the only ‘true’ AGM lead-acid starting battery on our list.
Optima 8020-164 RedTop is made using spiral-wound plates, offering a large surface at a relatively low weight. it weighs only 31.7 pounds, which is ~65% of NorthStar NSB-35AGM and Odyssey 35-PC1400T battery.
In terms of starting/cranking performances, Optima 8020-164 RedTop features 720 CCA (740 CCA NorthStar, 850 CCA Odyssey) and 910 MCA (880 MCA NorthStar, 950 MCA Odyssey). excellent cranking characteristics for such a lightweight AGM battery.
Optima 8020-164 RedTop physical dimensions are 9.38 x 6.75 x 7.69 inches (it is also wider than the ‘standard’ 9 1/16).
20h capacity is ‘just’ 44 Ah, and RC value is 90 minutes. Optima 8020-164 RedTop is not designed for anything but cranking/starting applications.
For the most up-to-date offers and prices, feel free to check the Optima Batteries 8020-164 35 RedTop Starting Battery Amazon link (the link opens in the new window).
Optima 8040-218 D35 YellowTop Dual Purpose Battery
Optima 8040-218 D35 YellowTop features the same design philosophy as Optima 8020-164 RedTop battery. spiral wound plates, AGM battery type.
Optima 8040-218 YellowTop is intended for both starting and deep cycling applications, making it a true dual-purpose battery that can provide 620 CCA, 770 MCA, 98 minutes RC, and features 48 Ah 20h capacity.
Also, it is slightly heavier than RedTop. 36.4 vs. 31.7 pounds, while the physical dimensions are the same.
Generally, Optima 8040-218 YellowTop is not as popular as the RedTop version, but it is, nonetheless, one of the most popular group 35 batteries, used in a broad range of applications where both starting power and deep discharges are required.
For the most up-to-date offers and prices, feel free to check the Optima 8040-218 D35 YellowTop Dual Purpose Battery Amazon link (the link opens in the new window).
Odyssey 35-PC1400T Automotive and LTV Battery
Odyssey 35-PC1400T is the heaviest AGM SLA group 35 battery on our list. it weighs 50 pounds (22.7 kg), but it also outperforms other AGM batteries as well:
Odyssey 35-PC1400T is a true dual-purpose battery. obviously, it is an excellent starting battery, but it is also designed to tolerate at least 400 cycles down to 80% DoD (20% SoC. State of Charge).
It can be fully recharged in 4-6 hours with no adverse effects on the battery.
Also, it is able to operate down to.40°F (-40°C) with somewhat decreased cranking amps, but nonetheless, that is a very low temperature. at those temperatures, lithium batteries are probably permanently damaged, while other lead-acid batteries are heaving huge performance issues (if such a low temperature did not already damage them).
With 3-10 years of service life, and a non-spillable and maintenance-free design, Odyssey 35-PC1400T is one of the best, if not the best, group 35 AGM battery.
Note: The author of this article is somewhat biased toward batteries with exceptional low-temperature performances. and Odyssey batteries are such batteries.
Price? Well, just like the NorthStar NSB-AGM35 battery, what you pay is what you get. an excellent, tough, and reliable battery with a very fine price tag 🙂
For the most up-to-date offers and prices, feel free to check the Odyssey 35-PC1400T Automotive and LTV Battery Amazon link ( the link opens in the new window).
Odyssey ODP-AGM35 Performance Series AGM Battery
Unlike the Odyssey 35-PC1400T battery, which is part of the Odyssey Extreme series, the Odyssey ODP-AGM35 battery is part of the Odyssey performance series, offering not-so-good discharge performances, but it is lighter and often offered at a somewhat cheaper price.
Odyssey ODP-AGM35 battery weighs 45.9 pounds (20.8 kg) and features a 20h capacity of 59Ah, 110 minutes RC, and 675 Amps CCA.
Note: some of these values are clearly stated on the battery’s casing.
On the other hand, the official Odyssey website states 765 Amps CCA, 770 Amps MCA, 900 Amps HCA, RC 117 minutes, and weight of 50.0 pounds (22.7 kg).
Personally, this 765 Amps CCA is too much for 770 Amps MCA and 900 Amps HCA, so the actual value is most probably 675 Amps CCA and NOT 765 Amps CCA.
Regardless of this confusion about the battery’s performances, the battery is a good low and high-temperature performer, but not as good as Odyssey 35-PC1400T.
For the most up-to-date offers and prices, feel free to check the Odyssey ODP-AGM35 Performance Series AGM Battery Amazon link (the link opens in the new window).
Long Story Short: If You are looking for a group 35 AGM starting battery, Optima RedTop is an excellent choice. it is a very good performer, especially considering its weight.
If you are looking for a good, all-around group 35 battery, consider Delphi, DieHard, or Optima YellowTop batteries. they all have their own pros and cons, just note that countless users have already tested the Optima YellowTop in various real-life situations.
But, Delphi and DieHard models are more affordable batteries than Optima.
And if you are looking for the best performer group 35 battery, consider either NorthStar NSM-AGM35 or Odyssey 35-PC1400 batteries. Odyssey clearly outperforms NorthStar by a nice margin, but they are both good and reliable batteries.
If the price difference is large enough, go for the cheaper one, and if not, Odyssey 35-PC1400T is the right choice.
How to Read ACDelco Battery Date Codes and Claim Warranty
The battery is the heart of your car’s electrical system. It provides the necessary power to start your car, keep the air conditioning on, and the headlights lit. For this reason, an automotive battery needs to be reliable, durable, and always in perfect working order. However, not all batteries are perfect when they make it out of the factory gates. Due to manufacturing defects, some batteries will end up not charging, no longer holding a charge, or not working as intended.
ACDelco batteries are one of the most popular batteries on the market and are well-known for their reliability, ruggedness, and longevity. ACDelco backs their batteries with 12- to 42-month warranties. well within the average lifespan of most batteries. ACDelco batteries are sold all over the world, but most of the ACDelco batteries sold in the United States are manufactured in North America.
If you are having problems with your ACDelco batteries, have it checked at their service and retails centers. There may be a material or workmanship defect on your battery that warrants replacement.
What are battery date codes
Battery date codes are used by manufacturers to indicate what when and where the batteries were manufactured. It also allows you to determine the age of your battery and whether it is still covered by the warranty.
A typical car battery lasts between two to five years. If your battery is old, it may no longer hold a charge like it used to and needs a replacement. Also, it may no longer be covered by a warranty since the coverage period was way past.
When buying a replacement battery, a newly manufactured one, needless to say, is better than old stock. Before purchasing a new battery, however, it is important to determine whether your old battery is still covered by the warranty to avoid unnecessary expenses.
Where to find the battery date code
The battery date code on ACDelco batteries is in the alphanumeric (consisting of letters and numerals) format. The code is usually printed on the battery tag placed on top of your ACDelco battery. The date code can be a bit hard to find especially when other codes such as model and serial numbers also printed on the battery tag. What sets apart the battery date code, however, is that it usually starts with either the letter “P” or “S”, followed by three digits, then end with another letter.
What do these codes mean
The first characters indicate the series of your ACDelco battery. The letter “P” stands for the Professional Series, “S” stands for the Advantage/60-Series, “H” stands for Heavy Duty, “K” stands for Voyager/Marine, while “M” stands for Maintenance Free.
The next three digits indicate the month and year the battery was manufactured. The first two numbers indicate the month while the third number indicates the year. January is represented by “01”, February by “02”, up to December which is represented by the month code “12”. As for the year of manufacture, only the last digit of the year is included in the code. If your battery was made in 2019, only the number “9” is included in the date code. This may cause confusion between batteries that were made before 2010 since a battery made in 2019 may be confused with one made in 2009. If you are unsure what year your battery was manufactured, seek help from your ACDelco service center or retailer.
The last character is the plant code which indicates where your battery was manufactured. This part of the code is most likely used by ACDelco to trace the origin of your defective battery. Please see the image below from ACDelco for reference.
How to read the ACDelco battery date code
To illustrate how to read the battery code on your ACDelco battery, look at the image below. This battery has a battery date code of “P039R” (highlighted in red) on its tag. This means that this ACDelco battery is a Professional Series battery manufactured in March 2019 at ACDelco’s plant “R”. (Grabbed image, replace if necessary)
How does ACDelco’s warranty work?
ACDelco provides a limited No Charge Warranty on their batteries. This means that ACDelco will replace your defective battery with a new one free of charge if it fails to hold a charge within the provided warranty period. ACDelco’s warranty period can range between 12 months and up to 42 months depending on the battery series. The warranty period is reckoned from the initial date of purchase of the replacement battery.
If your ACDelco battery is the original battery that came with your new GM vehicle, it is covered by a limited warranty of three years or 36,000 miles, whichever comes first, for Chevrolet and GMC. For Cadillac and Buick, the limited warranty is 4 years or 50,000 miles, whichever comes first. In both instances, the original battery must be taken to the GM dealership for replacement.
Things to know before claiming warranty
It is important to remember that not all damages to your battery are covered by ACDelco’s warranty. The battery warranty is limited to material and/or workmanship defects and does not include damages arising from, but not limited to the following:
- Improper use of the battery from its intended purpose or specification;
- Deliberate abuse;
- Normal wear and tear;
- Negligence, alterations or accidents;
- Prolonged storage or minimal use resulting in battery discharge;
- Electrical faults such as short circuit, excessive load, and faulty wiring;
How to claim under the warranty
If you wish to have your warranty-covered battery replaced, you must return the battery together with your dated sales receipt to your ACDelco service center or retailer. ACDelco technicians will check your battery for material and/or workmanship defects and identify the problem with your battery. If the battery is found defective, ACDelco will provide you with a new battery of comparable performance free of charge.
Will the new replacement battery covered by a warranty
The new battery will receive the remainder of the original warranty. This means that in the event that the second battery fails, the original date of purchase will be used as the reckoning point for the warranty and not when the original battery was replaced.