Battery Equivalents and Replacements

How to Convert Cold Cranking Amps (CCA) to Amp Hours (Ah)

The conversion between Cold Cranking Amps (CCA) and Amp Hours (Ah) is not direct for one very simple reason: Cold Cranking Amps describe the battery's ability to provide strong currents required for starting/cranking internal combustion engines, usually for 30 seconds, while Amp Hours (Ah) describe the battery's capacity and its ability to provide a certain current for, usually, 20 hours.

Basically, Cold Cranking Amps (CCA) and Amp Hours (Ah) both describe the battery's capacity and its ability to provide current for some time - they are just two extremes of battery usage.

Updated: March 9, 2024.

optima redtop 35 1

Cold Cranking Amps (CCA) vs. Amp Hours (Ah)

CCA (Cold Cranking Amps) is the value (given in Amps) of the maximum current that a new, fully charged, 12V battery can deliver for 30 seconds, with the voltage NOT dropping below 7.2V, at 0°F (-18°C).

Of course, there are several definitions of the CCA value, which are standard dependent, but this is the most common one.

Capacity is the value that directly describes the capacity of the battery and is given in Amp Hours (Ah).

The capacity of the new, fully charged 12V lead-acid battery is the value of the constant discharge current delivered for 20 hours without the battery's voltage falling below 10.5V, at 80°F (~27°C), multiplied by 20h.

For example, a 100 Ah lead-acid battery can provide 5 Amps for 20 hours.

The capacity of the lithium and other similar batteries is the value of the constant discharge current delivered for usually 20 hours without the battery's voltage falling below cut-off voltage, multiplied by, usually, 20h.

Obviously, when dealing with lithium batteries, it is very important to check the actual values - some manufacturers provide 1h capacity, some 5h capacity, some 10h capacity, etc.

When trying to convert Cold Cranking Amps (CCA) to Amp Hours (Ah), the main problem is that this conversion depends on the battery model, chemistry, intended use, and similar - it is important to note that there are starting, dual-purpose, and deep cycle types of batteries, each designed somewhat differently from the other.

car battery amps m

Starting batteries are the most popular type of car batteries and are used for cranking the engine and for powering various lighter loads (lights, audio, security system, and similar) while the engine is turned off.

However, starting batteries should not be used for deep cycle applications since their plates are relatively thin with a large surface and are optimized for high current applications.

Dual-purpose batteries are unable to provide as strong cranking currents as starting batteries, but they tolerate much better deep-cycle use. Dual-purpose batteries are used as cranking batteries and for powering various loads while the engine is turned off.

Dual-purpose batteries are very common industrial and marine batteries, becoming more and more popular even in cars due to the increased power demand during periods when the engine is off.

Deep cycle batteries are optimized for deep discharge and cycle applications - they are unable to provide strong currents, but they cycle well.

Cold Cranking Amps to Amp Hours Cross Reference Chart: CCA to Ah and Ah to CCA

The following cross-reference chart lists average CCA and Ah values for starting, dual-purpose, and deep cycle car, RV, marine, and light industrial batteries, depending on their BCI group:

BCI Battery Group Starting / Cranking Dual Purpose Deep Cycle
Group 8D - 220 Ah, 1450 CCA 250 Ah, -
Group 22NF 55Ah, 500 CCA 60Ah, 745 MCA 55 Ah, -
Group 24 - 76 Ah, 840 CCA 85 Ah, -
Group 26 50Ah, 550 CCA - -
Group 27 - 90 Ah, 900Ah 100Ah, -
Group 31 - 100 Ah, 1000 CCA 120 Ah, -
Group 34 55 Ah, 800 CCA 60 Ah, 750 CCA -
Group 34/78 50 Ah, 800 CCA 65 Ah, 850 CCA -
Group 35 44 Ah, 720 CCA 60 Ah, 740 CCA -
Group 41 (T65, 54LB) 50 Ah, 650 CCA - -
Group 47 (H5, L2, 55L2) 60 Ah, 600 CCA 50 Ah, - -
Group 48 (H6, L3, 66L3) 70 Ah, 760 CCA 70 Ah, 750 CCA -
Group 49 (H8, L5, 88L5) 92 Ah, 850 CCA 90 Ah, 850 CCA -
Group 51 (51R) - 60 Ah, 700 CCA 60 Ah, -
Group 58 (58R) 50Ah, 550 CCA - -
Group 65 - 75 Ah, 850 CCA -
Group 75 55 Ah, 760 CCA 55 Ah, 750 CCA -
Group 78 55 Ah, 760 CCA 65 Ah, 800 CCA -
Group 85/86 - , 625 CCA 55 Ah, 730 CCA -
Group 94R - 80 Ah, 800 CCA -
Group 95R (H9, L6) 105 Ah,  925 CCA 105 Ah, 950 CCA -
Group 96R - , 600 CCA 50 Ah, 600 CCA -
Group GC2/GC2H (6V) - - 215 Ah, -
Group GC8/GC8H (8V) - - 180 Ah, -
Group GC12 (12V) - - 150 Ah, -
Group U1/U1R 35 Ah, 400 CCA - 35 Ah, 300 CCA
Group YTX4L-BS/YTZ5S 3 Ah, 50 CCA - -
Group YTX5L-BS 4 Ah, 70 CCA - -
Group YTX7A-BS 6 Ah, 90 CCA - -
Group YTX9-BS 8 Ah, 135 CCA - -
Group YTX12-BS 10 Ah, 185 CCA - -
Group YTX14-BS 12 Ah, 200 CCA - -
Group YTX14AH/YTX14AHL-BS 12 Ah, 210 CCA - -
Group YTX20L-BS 18 Ah, 270 CCA - -
Group YTX24HL-BS 21 Ah, 330 CCA - -
Group YTX30L-BS 30 Ah, 385 CCA - -
Group YTZ10S 8 Ah, 180 CCA - -
Group YTZ14S 11 Ah, 230 CCA - -

Note: again, these are 'average' values since they can differ significantly between the batteries of the same BCI group - for example, Optima batteries are known for their ability to crank large engines despite having a relatively lower capacity (and weight!) due to their spiral-wound cells.

On average, CCA to Amp-hours relation depends on the battery type, and on average, it is:

  • starting lead-acid batteries: Capacity (Ah) x 10-16 = CCA (Amps)
  • dual-purpose lead-acid batteries: Capacity (Ah) x 8-12 = CCA (Amps)
  • deep-cycle lead-acid batteries: Capacity (Ah) x 4-8 = CCA (Amps)

Note: many manufacturers limit (at least on paper) the maximum current of their deep-cycle batteries, emphasizing the fact that they are not designed for such use. Also, smaller motorcycle/Powersports starting batteries achieve starting currents that are 20+ times their 20h capacity.

In order to check actual capacity and CCA dependency, always check the battery documentation and use these values only as orientation values.

Lithium Batteries CCA to Ah Conversion

Most automotive and light industrial lithium batteries are deep-cycle Lithium Iron Phosphate (LiFePO4) batteries that feature Battery Management Systems (BMSs) that disconnect the battery when the temperatures are low, sometimes already at 32°F (0°C), although most often at 14°F (-10°C).

Note: many newer lithium batteries can be discharged down to -4°F (-20°C), but their output currents and actual capacities are limited at those temperatures - at least until the cells get warmer.

Also, most lithium batteries have discharge currents limited to 1C continuously and usually 2-3C for 2-5 seconds - for example, a typical LiFePO4 12V 100Ah battery features a maximum continuous current of 100 Amps and surge current of 200 Amps for 2-5 seconds.

Thus, talking about the true CCA value for such batteries makes no sense.

However, for some starting lithium batteries, their manufacturers provide "CCA" values, which are actually the maximum currents that these batteries can provide, usually for 3-5 seconds at 32°F (0°C) or even at 77°F (25°C).

Note: one of the CCA limits for lead-acid batteries is voltage not dropping below 7.2V (1.2V per cell) - 12V Lithium Iron Phosphate (LiFePO4) batteries have 4 cells (4S construction), and with 3.2V per cell, that is 12.8V per battery. Forcing LiFePO4 battery down to 7.2V (1.8V per cell) would probably damage the battery. Hence, their built-in Battery Management Systems disconnect the batteries usually around ~10V.

Direct conversion from CCA to Ah and back for lithium batteries is impossible to give since they vary significantly - for example, there are starting lithium batteries for Powersports applications that have their CCA (Amps) in the 50+ range of their nominal capacity given in Amp Hours.

CCA (Amps) = Capacity (Ah) x 50

Such batteries offer great weight savings and improve engine starting/cranking, but they tend to be more expensive than lead-acid batteries.

weize ytx20l battery 1

For example, one such battery is Weize Lithium YTX20L-BS (Model BAC-0107) LiFePO4 Motorcycle Battery (Amazon link, opens in the new window), which has a nominal capacity of 8Ah and is rated at 600 CCA.

In reality, this battery can provide 600 Amps for 3 seconds, which is usually enough to crank relatively large gasoline and even diesel engines - not bad for a battery weighing just 5.874 pounds (~2.67 kg) and supports 50k+ starts during its lifetime.

Long Story Short: When converting CCA to battery capacity and vice versa, one has to note the battery chemistry and type.

However, as the batteries age, their capacities decrease, just as their ability to crank the internal combustion engines decreases.

Lead-acid or lithium batteries, that is the question ...

Personally, unless you really need to save some weight, go for starting an AGM (or Gel-cell) battery, especially in very cold or hot weather.

Lithium batteries often ensure a cleaner and safer start, but they have their cons as well.

oldie but goldie car w600px

For example, if you have a vehicle that is older than ~1995-1998 and you want to replace the lead-acid battery with a lithium battery, consider replacing charge controller electronics, which was often so simple that it relied on the lead-acid battery to stabilize the voltage in the car's electrical system.