Maximum amps for testing AGM capacity?

pianotuna wrote:
There are those who would say 13.6 won't ever charge a single battery fully.

That's mostly the voltage I use for my two (expensive) 115 AH Group 31 12V AGM deep cycle RV batteries. The ammeter eventually goes to zero amps being accepted if I leave them on 13.6 volts long enough.

Maybe I'm slowly destroying my batteries - don't know - and so far for years in these forums no one has been able to provide a clear and simple electro-chemical engineering based reason(s) as to why I am slowly destroying them. They get mostly charged during trips and floated month after month after trips using that same 13.6 volts and a permanently installed ammeter for monitoring their continual charging current acceptance rates.

I've read several technical papers on lead acid battery charging and so far none have stated outright, or implied, that 13.6 volts is a slowly destructive way to charge lead acid batteries. The technical papers only state/imply that it will take LONGER to fully charge lead acid batteries using 13.6 volts and that whatever charging voltage is used - the batteries should not sit too long between charges with no charging voltage being applied - which I understand the electro-chemical reaon(s) for.

I've saved around $200 dollars by continuing to use (mostly) the stock converter that came installed in the RV for charging of it's coach batteries.