Here is the math behind:
http://www.subsim.com/radioroom/show...postcount=7896
To work out the recharge time use formula Ah / Amp = time.
therefore assuming that your craft is travelling at 'Slow Ahead' using the information above the battery has a rating of 9160Ah, as the information states the charging is done in 3 phases, so for phase 1 the battery is charged at 1650 Amp.
9160Ah/3=3053.333
3053.333Ah/ 1650Amp=1.85 Hours
for phase 2 the amps are slowly reduced from 1650Amp to 415Amp giving an average of 1650-415=1235Amp
3053.333Ah/ 1235Amp=2.47 Hours
phase 3 3053.333Ah/ 415Amp=7.35 Hours
giving a total for normal charging off 1.85+2.47+7.35=11.67 Hours
for a 'Fast charge' the information states that it reduces the time by 1/3
11.67/3=3.89
giving a 'fast charge' time of 11.67-3.89=7.78Hours.
These figures are only an approximation as recharge systems do not work at 100% efficiency today never mind 80 years ago! you could probably add another 20% - 40% to these figures.
Les