PD4655 Charging Graph
I have been reading quite a bit about different converters and charge rates, specifically some claims that PD's seem to drop off earlier than other brands. That is not what I have noticed on my setup,...
Forum Discussion
pnichols wrote:mena661 wrote:
You seem to think AGMs are some mystical battery ...
Nope on the mysticism.
All I know or care about regarding (my) AGM RV batteries is:
1) They don't require any maintenance - they just sit there, shut up, and do their job year after year.
2) They have less internal resistance - so they absorb more charge current under any applied charging voltage.
3) They require a float voltage of 13.5 to 13.8 volts, so when switching to them I could keep right on using my good old 13.8 volt fixed voltage converter instead of spending the additional $$ for a multi-stage charger retrofit to my RV.
By the way, for fastest charging (which I don't care about), my AGM batteries can take per their label, and if one desires, 14.4 to 14.8 volts. I call this "14.XX volts" - what my alternator output is for awhile when starting out down the road before it's voltage starts to slowly decline ... I assume most/all motorhome alternators are supposed to act this way (kindof like an infinite-stage charger).
It is not the alternator that is acting that way, it's the battery. Due to chemical reactance, temperature, specific gravity, etc. The battery, at a given charge voltage at the terminals, at a given temp and at a given specific gravity, is the limiting factor. The more sulfr on the plates that is not hard, the more amps the battery can take.
Exceptions are at the extreme end of the bell curves, 0 to 10% charged, and 90 to 100% charged, due to the ionic state of the electrolyte solution.
