Bruce In Bangkok wrote:

O.K., if you want to be pedantic,
How much voltage do you need to pump approximately 2000 X ( 6.242 ×
1018^18) electrons per second into a battery.

Remember this from an earlier post?

"Recharge rate won't exceed 15% average of the battery AH capacity."

Thus:

2000/15% = 13,333 AH of battery bank is required for a 2,000 amp
charging rate.

Normal charging voltage is anywhere from 13.2VDC-13.8VDC.

Lew