Charge controller recommendations
I have a small solar charging system consisting of two 12v 75w panels wired in series and a failing cheap MPPT charge controller. I may be acquiring another identical panel too. I'm currently leanin...
Forum Discussion
BFL13 wrote:
Not sure how they can extend the Vabs when batts are low. Vabs is reached sooner at a lower SOC with a higher charging rate.
If you get to Vabs at 65% SOC then you would expect to be in the Absorption Stage longer than if you got to Vabs at 95% SOC with a low charging rate.
So somewhere in all this you have to relate to whether you have 50w on your 440AH bank for storage or whether your camping set of 600w on the 440AH bank is also used when in storage and the controller has to be able to throttle back that 600w from way overdoing it.
Perhaps I am confused what you guys are really talking about due to some terminology confusion on my part.
You have it right. The extended time is based on start voltage. A battery at 12.6+ in the morning is assumed to be in storage and get just a few minutes Vabs. Battery starting at 12.2 in the morning gets an extended Vabs. Even lower can cancel float and remain in absorbtion all day. All set points adjustable.
And I agree a small system with a large battery may never need a long absorption time. It may never even go to float when in use.
