Confusion on battery charging
I am confused about the best practices for charging batteries. For 7 years I had 300 AH of Lifeline AGM batteries, 270 watts of solar and a simple charging system. My old camper has a 110 volt c...
Forum Discussion
JimK-NY wrote:
My battery voltage is about 12.7 in the morning. That corresponds to using only about 10% or 30 AH. Last week the temps were lower so I used my furnace and dropped to 12.6. Even with the furnace I doubt I pull over 30 AH most nights. If I have decent solar that should be less than 3 hours of charging. No way! I can charge for hours longer and never seem to reach 14.3 and 1 amp.
270W solar is not a "decent" size these days :).
Seriously though, 270W on clear summer day AND if starting at 90%, should suffice. Here is the problem:
1) Not all days are clear. Hence - you need more solar for cloudy days, to enter Absorb quickly and stay there for 2 hours.
2) Your controller restarts the Absorb when there is not enough light to keep Absorb 14.x - all of them do, but yours wants to keep it for 2 hours no matter what. And then it restarts 2-hour timer every time again.
If it takes all day to even get to 14.x, then you don't have enough solar, given your loads, weather and battery state of charge. Or Don Piano is right (he often is), and your battery is a poor shape after years of under-charging and takes a long time to get to 14.x.
It would've been nice to upgrade controller too, so that it wouldn't restart 2-hour timer every time.
I am not sure why you want the current to drop down to 1 amp. Unless Lifeline are really that different, battery is considered full when current drops to 1% of capacity, or 3A in your case. This is when it's in Float already.
