AGM batteries - are they better?
Upgrade to an AGM battery. You can safely mount them inside, and upside down, and they will out-perform any flooded battery you ever owned! Here's a quote from another thread. It's typical of other...
Forum Discussion
CA Traveler wrote:
Partial comparison:
Lifeline GPL-4CT 220AH 66lb 10.28x7.05x9.92H $316
Interstate GC2-HD-UTL 216AH 64lb 10.25x7.12x10.85 $149
Interstate GC2-XHD-UTL 232AH 65lb 10.25x7.12x11.25 $153
Virtually the same except for cost.
OP It doesn't seem like AGMs are for you as for most RVs, which is likely the cost factor.
I don't know of any RV that has a 500A charger. I suspect telcoms want a very fast rate when power is restored and may use very high charge rates.
Generally for my AGMs charging is about the same profile rate as a flooded battery. It is a different profile but not to far different. My 100A Magnum generally charges at a maximum of 80A due to design cost tradeoffs and I haven't measured my alternator charge rate but suspect it's about the same.
All of this makes me wonder why Monaco installed AGMs in my rig. They are outside and the higher GC2 height is not a factor. Less self discharge, lower internal resistance, better voltage regulation, no corrosion, no checking/adding water, what?
Hmmmm. For comparison, my Sam's Club Duracell EGC2 230AH 6 volt batteries were $85 each and weigh 66 pounds IIRC.
It makes sense that lower internal resistance would result in faster charge rates at all parts of the charge curve, but you don't seem to be seeing that. I've optimized my 80A PD9280 charge system with short fat charge cables to hold pretty close to 80A during bulk charging. But, as the battery voltage rises to within 0.1 volts of the 14.8 charger voltage, the current is limited by the cable resistance and the battery internal resistance. I'd love to see some comparison charge tests between AGM and FLA batteries of similar capacity.
