I have a 24volt sytem consisting of 2 strings of 6volt/225amphour.
1 string is Trojan T-105's, Other string is a no name job but the
batteries/casing are identical to the Trojans except they are white with red lids
instead of the maroon like the trojans.
The trojan string I bought new 3.5 years ago. The red/white no name string was given to me recently as throw aways.
First inspection of the red/whites showed they had not been maintained at all, the electrolyte levels where way low(each battery took almost a litre to top up!) and the tops where dirty and wet. Also they show some bulging on sides. I charged them
and then left them alone for a week or so and they held at 25.3volt so I gave them a go and they appear to be going ok.
I am running both strings paralell and they seem to be ok after a few weeks or so.
Yesterday I decided to check each 6volt battery with multimeter.
First checks were made with power coming in from panels as well as power coming out from inverter. All batteries showed more or less equal voltage(+- 0.02volt).
Last night I switched to another battery bank(2 x 12v/180amphour sealed, valve regulated FullRiver) and left the other bank to settle overnight.
This morning I performed the same check of each battery(batteries remain connected to each other). The noname red&whites all showed 5.95volts. 3 of the Trojans showed 6.05volt but 1 showed 5.69volt. The positive terminal on this battery has turned black as well.
Is this battery toast?
What if anything can I
should I do?
Is it ok to have 2 different strings like these connected in paralell?
Also is it ok to run the string of Trojan's and the String of Fullriver sealed type together in paralell?
tia
Ian.