AGM batteries - are they better?

full_mosey wrote:

DryCamper11 wrote:
I'm trying to figure out where it makes sense for me to spend money, and the more I look, the more convinced I am that I should focus on solar to finish off the absorption stage slowly, instead of trying to speed up my gen charging in that region. I just don't spend enough time in bulk mode charging for the higher charge rate that you get there to be an advantage for me.

I depend on solar to the extent that the genny is only needed for supplemental charging. The most beneficial use of a genny is during bulk and partway into absorption because as the charger's wattage drops, the effective use of fuel is worse. After that point, I shut down the genny and the solar takes over.

You cannot speed up the charge time after bulk unless you stress the battery with higher volts. With wets, you get extra bubbling instead of faster charging and with AGM without temp-comp(TC) you risk thermal runaway.

Bubbling wets may be wasting fuel when done too often. The only reason to bubble wets is to stir the acid and that takes minutes, not hours. Cracking water into H and O for hours simply wastes fuel and extra volts is bad for the + plates. Even wets will benefit from a TC charger followed by periodic bubbling.

All this emphasis on faster charging between wets and AGM is way overblown. AGMs do charge faster, but the difference is a paper-cut.

For me the really big AGM pros are:
1. low maintenance,
2. Living space installation,
3. Very high inverter draws.

Without any of these pros, it is usually better to choose wets.

HTH;
John

Correct, in the end the ACTUAL difference in charging acceptance is so small that in the MAJORITY of cases MOST users will not see any real or significant improvement in charge times by using AGM.

This basically takes the supposed advantage of faster charging out of the equation for MOST users.

In the end you might see a few minutes shorter charge time for AGM when compared to FLA.

Certainly not enough "advantage" to warrant me spending extra for that "feature".

For me I value the MOST Ahr for the $ and the clear winner for me was 6V GC FLA batts from Sam's..