[creeky]

Thx Pinballlooking. Its been a pleasure reading your journey as well. (One thing I noticed about the Volt batteries, as posted above, is there were 3 low cells on one battery. After charging and watching they've held up perfectly. Leading one to wonder why they were so low. And even more so, consider if it was the BMS or volt charger at fault. Something for Volt owners to wonder at also.) smile.

On with the show

So after 27 days I have sent 112kw of solar power to the batteries. I have sent 94kw of solar power to my inverter. And I have done some very bad math.

I take an average of 7 days of charging back when I had the batteries under testing. There were days when the batteries being charged for the first time then sat, hooked up to the solar charger, and then topped up the next day.

This average indicates a solar controller daily load of 130w per controller.

Hence, (18kw of loss - 7kw for the 2 solar controllers load) * 92% for inverter/cable loss = 80% system efficiency.

And it would appear the batteries are aprox 91% efficient.

Note: take none of this too seriously. The solar controller(s) load could be off by a factor of 1.5. And there are other problems. Accuracy of the $18 ammeter by ex.

Yet for all intents

However, be that as it may, and all that. Total battery voltage variance is now at .02v.

Cell balancing?

I appear to have found a simple method of using high cells to top up low cell voltage. both lowering high cells and boosting low cells. So cell balancing in a very hands on way. More on that after further testing.

My quest for a balancer/bms continues. I found some really good docs on the balancing/bms chips that the Volt uses. I haven't had time to read them yet.

Update complete!

PS-still gives me a tingle when I, as I did last night, turn on the dishwasher before going to bed. After watching TV or listening to music late into the eve. Huzzah.

PPS-yesterday was cloudy in the a.m. with full sun bursting onto the panels at peak generating time. My "summer angle" set of 1kw of 8 year old panels delivered 965 watts. Interesting given a) age of the panels; b) haze/dirt affecting the solar gain c) the high temp of the panels on a very hot afternoon d) prorated at 20% efficiency loss over 25 years should mean that the panel set is only capable of delivering 930 watts peak.

I would say 965 is full on original power spec given the panel temp and conditions.