AI6YR BenLet's see how the solar shed is doing today. Looks like the AGM batteries still holding up, but seeing fairly deep discharge overnight. 190Ah battery bank dropping to 12.2V. About 25 to 35W constant load. #solar #batteries
Solar panels do seem to be working better after adjustment to the charging profile. Currently in absorption phase, AGM batteries starting to top off. #solar #batteries
4 hours to float. 690Wh off the solar panels after starting at 12.2V on the battery bank this morning. #battery #agm #solar
kajer :unknown:@ai6yr victron crew!! 
Hippy Steve@ai6yr how did the AGMs do overnight? looks like maybe 12.2v was the low? Did you have to add a supplemental charge?
@exador23 No supplemental charge, 12.2V was the low... It's a deep draw, but acceptable as we get more sunlight.
@ai6yr Great news!
@ai6yr I'd missed the first post. Assuming 16hrs at 3A load that's about 47Ah. 12.2V under light load is maybe 12.3V at rest, which would be about 70% SOC.
If 47Ah is 30%, that suggest you've still got about 150Ah of capacity. Not too bad considering what they've been through.
These are all rough estimates, of course.
@exador23 Thanks for the second set of eyes on this! Now that I have the system set to turn off all the load at 11.9V, hopefully will forestall an early death on these. That atmospheric river (with no sunlight) was brutal. Looks like the stress fried the Noco charger I had out there to keep it trickle charged, too, lol. (the emergency charger out there is now an ancient Harbor Freight charger, which probably is too brutal for the AGM on a normal basis, but only pushes things to 13.8V max).
@ai6yr They should be fine through the summer. Might try putting them on a de-sulfator before winter to see if that can bring back some of the capacity to make it through the long nights. Might as well get as much use out of them as possible before switching.
@ai6yr oh. And as it gets hotter, you may want to reassess that absorb time. warm AGMs accept a charge much easier than cold ones. Now that I know your Ah, if the current to the battery drops much below 2A, they can go to float instead. As the days get longer the float time will also increase, which makes up for the shorter absorb.
And if you ever hear a whistling or hissing sound, stop charging immediately and assess things. either the voltage or current is too high and you're losing electrolyte through the release valves. Also since, they've gone through some abuse, occasionally inspect for any bulging of the case and take them out of service if so.
Bosque Bill@ai6yr Yikes, that's too low, at least if they're like mine. The AGM battery manufacturer's rep told me they shouldn't be discharged below 12.3v if you want to preserve their lifetime.
@bosquebill 12.2V is supposedly 60% state of charge. 12.3V is 70%, so that is saying you should only discharge 30% capacity... which would require significantly more battery bank for consumption.
Shoe BillAre these batteries like phone batteries, where you're ideally supposed to keep it between 20% and 80% at all times (supposedly)?
Scott Herr@ai6yr Theoretical example,
190-Ah 12-V battery bank, 100% full
- 28.8 Ah (30 W @ 12.5 V is 2.4 A, for 12 hours)
= 161.2 Ah, 85% full