Hi. So I am returning to this thread because we are still having battery problems.
Summary:
I started this thread trying to understand why I wasn't getting even close to the stated capacity of my batteries after just a few months of installing them and they had been working fine. After much help from this forum, we found that two of the eight batteries were very low in voltage in the morning and the others were up over 12V. My battery vendor immediately replaced the two bad batteries and everything was good, batteries staying up over 50 volts all night long...for a couple months...
Then, a couple months later, all of a sudden we lost power overnight. I check the batteries and again there are another two at 6 or 7 volts (not the two he had replaced), and the other six batteries are over 12.5 volts. I contacted the battery vendor again, and he replaced those two batteries, free of charge. He tells me there must be something wrong with my system, because in the 4 years he has been installing systems with these batteries he as never had one fail, and he also says the "bad" batteries he replaced are now installed in his system and doing just fine.
I don't know how my system can be causing two batteries to fail - doesn't my controller just see one large 48V battery? Each time there has been one bad battery in each string of four.
Some here had recommended installing an equalizer so the batteries charge and discharge equally.
I went ahead and installed two of these from Watt247, one in each string of four batteries:
https://watts247.com/product/eq-48-...-batteries-or-any-x-3-2v-batteries-in-series/
I like the fact they display the voltage of each battery and that they do keep them equally charged.
Everything has been good for the last few months, even with some overcast skies the batteries have easily made it through the night.
Then just last week, we started losing power again! Now that I have the equalizers I can see that all of the batteries are equally down to 11.5V, causing the inverter to turn off at the <46V set point.
I haven't done it yet because it is a pain, but should I remove the equalizers and see if two of the batteries are down lower than the rest again...?
The guy who sells the batteries is surely going to blame my Growatt unit again. But how could my controller keep killing batteries?
Thanks!!