Battery question

For lead acid

Bob

In the ideal world, yes.

In the real world, no... most batteries are "rated" at their "C/10" rate, meaning that a 50Ah battery can supply 50/10=5 amps for 1*10=10 hours (=50Ah total). If you draw the "1C" rate (50A), you'll get noticeably less power out of it (

No. That's a nominal rating. You'll need to look at the manufacturer's data sheet but the BCI rating system for lead-acid batteries specifies a discharge rate of 1/6 the AH rating for 6 hours (IIRC). So, you should be able to discharge at 8.3 A for at least 4.8 hours (80% rated capacity). The higher the discharge rate, the less you'll be able to pull from it; at 50 A, it's not going to last long.

The difference in energy extracted at high rates also depends on the battery construction. Batteries designed for high discharge rates do considerably better; batteries designed for way high capacity, with discharge rates sacrificed, will do considerably worse.