Originally Posted by Civilguy
Fascinating. So, high voltage is not enough for anti-sulfating, we need the amps too?
Can you tell I'm well-practiced in the art of extended analysis and immediate inaction?
Different purposes. Pushing the voltage up above 'full charge' and holding it there for a bit equalizes the cells. That's a good thing to do, and even a BT Junior will manage it on any battery over time as long as the voltage leakdown rate (self discharge plus any parasitic loads) is less than the charge rate.
Pushing current through a full battery also causes it to hydrolyze the electrolyte into hydrogen and oxygen
. More current = more bubbles per unit time. Too much of this is definitely a bad thing, and is why an old-school trickle/float charger can't be left running unattended on a battery for weeks or months - you have to stop
putting current through the battery at some point. Knowing when to stop is what differentiates a battery maintainer from a trickle charger.
Flooded lead acid (FLA) batteries also need some kind of agitation to keep the electrolyte from stratifying in bad ways. You get this for free in any kind of a vehicle that's moving. The bad news is that trailer batteries generally don't move around during winter storage. Overcharging the battery for a few hours at a high enough current will generate some gas and stir the electrolyte. This is something that people with stationary battery banks on solar
systems do regularly to maintain battery health. As long as you check your electrolyte levels periodically and top up as needed to replace the electrolyzed water you'll be fine.
My SOP is to turn the converter off (I have it on its own circuit breaker) when the trailer is pickled unless I anticipate using a lot of 12V (say, running the MaxxFan for a while). I then hook up a battery maintainer to the battery and let it do its thing. I find myself messing with the trailer periodically through the winter, so it's not a big deal to flip the switch on the Schauer over to manual for a while to let it stir the electrolyte after a month or two - I do have to remember to turn it back off, though...