Originally Posted by Deano
Question for those of you who grasp all of the ratings for batteries.
I have a pair of GC2 batteries in my 05 210 Pop. They each are rated at 122 minutes at 75 amps and 20 amp hour capacity of 232.
I need to know the maximum amp draw over several minutes that will not damage the batteries. The expected draw would be approximately 100 amps or slightly less.
I assume you mean the 20 hour rating is 232ah, which is actually very good for GC2 batteries. 100 amps would be an easy thing for AGM batteries, probably OK for most wet cells. The fact that you batteries carry a reserve minutes rating is somewhat a worrisome as that would often indicate an non true deep cycle battery.
It is probably best to just give it a try and see how much the voltage drops at the 100 amp load. If you start dropping into the low 10 volt range, you are pushing things pretty hard.
It is likely you will find that the 100 amp load will be fine when the batteries are at 50% full or more, but shakey at less than that. When we had 260ah of wet cells (Trojan GC2 batteries) that is how it worked out for us. AGMs will do better than wet cells.