After reading about submarines in World War II, I was curious about their battery capacity, specifically in comparison to modern Battery Electric Vehicles (ie Tesla, Bolt, Leaf, i3, etc).

I haven't been able to find a source that either answers the question in kWh or gives me enough information to calculate it myself.

My current guess is about 30 kWh, based on a figure of 12000 Ah in a 120 cell system, and a voltage of 2.75 V - 1.05 V

I would accept an answer for any class of submarine in WWII, but I was looking at the US Balao class.

  • $\begingroup$ What was the chemistry used in the batteries you are looking at? $\endgroup$
    – Solar Mike
    Jan 23, 2019 at 20:13
  • $\begingroup$ @SolarMike Lead Acid $\endgroup$ Jan 23, 2019 at 20:58
  • $\begingroup$ Old topic but I am not sure how the maths are done... With lead acid, 2.25V nominal x 120cells in series and 12000Ah cells we get about 3MWh, not 30kWh... maybe Ah rating is wrong. $\endgroup$ Apr 23, 2020 at 17:16
  • $\begingroup$ @ÁlvaroSatuéCrespo my comment to you was lost (mod changing your answer to a comment) so repeating it: are you assuming each cell has a capacity of 12000Ah ? $\endgroup$
    – Solar Mike
    Apr 23, 2020 at 20:12
  • $\begingroup$ @ÁlvaroSatuéCrespo It's been a while since I asked this question, I wish I had stated it better.The 12000Ah refers to the whole system, not one cell; so it's 2.25*12000 = 27000 V*Ah = 27000 Wh = 27kWh. I do not recall where I got the figure of 100 Ah per cell in this class of submarine. $\endgroup$ Apr 24, 2020 at 21:49

1 Answer 1


Collecting bits from sites,


World War II American fleet submarines had two batteries, each composed of 126 cells. By comparison, a 12-volt car battery contains only 6 cells, each producing about 2.25 volts when fully charged, with a maximum power output of about 45-50 amps. Each cell in a submarine battery produces from 1.06 volts when fully discharged, to 2.75 volts at the optimum output, so connecting the 126 cells in each battery in series gives a usable output of from about 210 to 350 volts, and a power output of as much as 15,000 amps with both batteries connected in parallel. (no mention of total amp-hrs)


My submarines (Oberon class of the 1960s-1990s) had two lead acid batteries containing 224 cells each with a nominal voltage of 440 volts.. The cells were rated 74.20 ampere-hours at a 5 hour rate (nominal voltage of each cell was 2.2 V)

448*74*2.2 = 73kWh


The US Navy "Balao" type submarine (1944/45) was fitted with 4 four Elliot Main (Electric Motors) two on each shaft, with a total horsepower of 2,740. While submerged, these motors were powered by two massive (each cell weighing 1650#) 126-cell batteries (in series) capable of delivering 5,320 Amp/Hrs each.

Assuming they meant Amp-hrs, and guessing 2.2 V per cell, 2.2 * 2*5320 = 23.4 kWh


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.