Getting to "Full" with Not Enough Solar
More on camping tactics etc to try to get batts full while off-grid and not enough solar per PT's "rules" (PT says you need at least 60w solar per 100AH of battery to "equalize" that day sometime b...
Forum Discussion
Doing one pair at a time now. First pair of 6s which stalled at 1.270 yesterday as part of the six batts, done. (Just over 1.275 now to settle near 1.280 I hope) First I put them on controller and got to Vabs fairly quickly then they were put on panel direct. All fixed by 1030. Now doing the other pair of 6s.
This time, on panel direct, voltage rose quickly to 15.4v So that proves the other thing about not enough solar, that there is a limit to what voltage it can get the bank to, same as with small battery chargers. I could not get the six up past 14.6, just sat there. 15.4v on just two batts with same solar panel-direct.
It seems possible that you could even have a situation with less solar per bank, that the solar would not even be able to get the batts to the controller's high set point voltage, and it would stay at that higher voltage, just below controller Vabs, negating any timer the controller might have for Absorption before dropping to Float.
This could be good or bad or not matter---a situational thing.
I won't find out today if the solar I have will be enough for the four 6s, now that the two 12s are disconnected from the bank. Last year this is what we had all summer---130w in contraption, plus four 6s. I did not have the same controller though, and some of the time was on panel direct (after I fried the first controller) so no data from last year on whether normal ops will get these four up enough. Should find out in the next couple of weeks.
Hope to get that $13 RJ Special "MPPT" controller in time before we leave here so I can test it out. Mid September expected delivery, so should have a week with it, all being well.
This time, on panel direct, voltage rose quickly to 15.4v So that proves the other thing about not enough solar, that there is a limit to what voltage it can get the bank to, same as with small battery chargers. I could not get the six up past 14.6, just sat there. 15.4v on just two batts with same solar panel-direct.
It seems possible that you could even have a situation with less solar per bank, that the solar would not even be able to get the batts to the controller's high set point voltage, and it would stay at that higher voltage, just below controller Vabs, negating any timer the controller might have for Absorption before dropping to Float.
This could be good or bad or not matter---a situational thing.
I won't find out today if the solar I have will be enough for the four 6s, now that the two 12s are disconnected from the bank. Last year this is what we had all summer---130w in contraption, plus four 6s. I did not have the same controller though, and some of the time was on panel direct (after I fried the first controller) so no data from last year on whether normal ops will get these four up enough. Should find out in the next couple of weeks.
Hope to get that $13 RJ Special "MPPT" controller in time before we leave here so I can test it out. Mid September expected delivery, so should have a week with it, all being well.
