Not Balancing Three 12v Right
This post is just for info in case anybody else has a similar situation I have learned the truth about wiring up three 12s as though they were two 12s. With the load and charging pos and negs o...
Forum Discussion
That smartgauge is what I was trying to say in the OP where I had three batts done as though two.
He says the middle battery discharges less than the end ones, but I didn't measure that. I saw the middle battery lagging on the recharge by its SG showing it not as full as the end ones.
I don't know why the middle battery doesn't come back on the recharge where it takes fewer amps, since it also provides fewer amps on the discharge. Maybe while camping there is more time for them to even out on the discharge side so the recharge is uneven right after, allowing no time (days?) for things to even out.
OnaQuest is right in warning this could be a bogus observation, not to be applied to anyone else's situation, but it is what I got with my messy set-up.
I did not take SGs while camping on completion of a 50-90 to see how the batts shared that. It was after getting home with the batts down and plugging in to let the converter bring them up (it is slow). By next day they are almost full, and that is when I took the SGs. I have seen this every time, so it was not just a one-off.
That set of SGs is to tell me if they need the high voltage finishing charge to get them to 100% which they always do need. The converter can't do it-voltage too low. I then have to do each of the three separately as mentioned with a charger that has the high voltage into the 15s. Then I can bank them as before put them all on the converter for a Float. It takes two or three days after getting home before the batts are all done up and on float.
(Leaving them on the converter for weeks instead is a disaster--the SGs do not come up to full. Got to get them into the 15v range like US Battery and the others say you do before going on the float.
The Float voltage is then able to keep all the batts at their baseline SGs despite the unbalanced set-up. Mex explained this was ok in a previous thread, as long as the battery taking the smallest share of the amps is still getting enough to overcome its own self-discharge.
He says the middle battery discharges less than the end ones, but I didn't measure that. I saw the middle battery lagging on the recharge by its SG showing it not as full as the end ones.
I don't know why the middle battery doesn't come back on the recharge where it takes fewer amps, since it also provides fewer amps on the discharge. Maybe while camping there is more time for them to even out on the discharge side so the recharge is uneven right after, allowing no time (days?) for things to even out.
OnaQuest is right in warning this could be a bogus observation, not to be applied to anyone else's situation, but it is what I got with my messy set-up.
I did not take SGs while camping on completion of a 50-90 to see how the batts shared that. It was after getting home with the batts down and plugging in to let the converter bring them up (it is slow). By next day they are almost full, and that is when I took the SGs. I have seen this every time, so it was not just a one-off.
That set of SGs is to tell me if they need the high voltage finishing charge to get them to 100% which they always do need. The converter can't do it-voltage too low. I then have to do each of the three separately as mentioned with a charger that has the high voltage into the 15s. Then I can bank them as before put them all on the converter for a Float. It takes two or three days after getting home before the batts are all done up and on float.
(Leaving them on the converter for weeks instead is a disaster--the SGs do not come up to full. Got to get them into the 15v range like US Battery and the others say you do before going on the float.
The Float voltage is then able to keep all the batts at their baseline SGs despite the unbalanced set-up. Mex explained this was ok in a previous thread, as long as the battery taking the smallest share of the amps is still getting enough to overcome its own self-discharge.
