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:
I looked up the MegaWatt unit. It is just a cheap 120 to 12 volt charge controller. I think I would spend more and get an automatic 3 stage charger. Anyway I am traveling and do not have that option.
I fail to see what is unreasonable about using solar panels. I think I should be able to fully charge my batteries when I am at 90% charge and have sufficient amperage to maintain the absorption charge for close to an entire day. That would be no different than setting the MegaWatt or other charger to absorption and powering it with a generator all day.
It just seems that something is wrong when a full day of charging on almost full batteries never achieves the standard for a full charge.
The problem with solar is in being able to do the Lifeline's 20% minimum amps for the Bulk stage. 300AH would be 60 amps.
Even if you could do that starting in the morning, that would mean your array could do much more by mid-day so that would be a huge array.
270w flat on the roof might do maybe 15 amps at noon? So it is not going to do much early in the morning.
However, if you are starting at 90% SOC, you would see a fast rise to Vabs of 14.3 with a very short time in Bulk, and tapering amps from there on. You can get to full that day.
What I don't know is if that means your "full" will not be down to the 0.5a/100 idea, since you didn't hit it with the 60 amps during Bulk.
