[Nick Flint Posts: 4958 Status: Offline]

Only fair to report further on my Motorhome problematic NEW Starter battery whilst connected to a 24 yr old solar Photo Volt grid.
New solar charging control unit looked nice, covered a few screw holes but did not improve the continuously DISCHARGING battery,
which was the opposite of desired performance.  :'(
I took many readings over many days in many different ways, but in short-
The solar panel is somehow discharging the battery although all readings show as expected.
Disconnect solar panel and M/Home terminals = total stability with CONTRARY to advice given by the battery supplier, does NOW give good results straight out of the box!
Voltage, Int res, EDC state of charge and state of health ALL read bang on when NOT connected to Vehicle.
Ive tested for parasitic leak and defused the clock and radio memory ATM so we shall see what happens as I slowly reconnect things.
My guess now is that perhaps the solar panel is not now behaving correctly, after 24 yrs of use/ (abuse?)
Life's rich pageant 

[Nick Flint Posts: 4958 Status: Offline]

Learned something today (see it was possible)---
NEW batteries show State of Health as around 80% ONLY on my battery monitor  as they are "apparently"-designed this way and ONLY approach better figures following on from cycled usage over a good few weeks (20-30 cycles).
I shall of course keep my tester handy which measures many parameters - int res, EDC, State of charge, State of health, and voltage. This follows on from replacing the solar charger monitor (24 years old) with a new, modern and clearly more up to the job doobrie. I had become less confident the old monitor was up to matters ref blocking diodes and actual charging.
The old removed unit does have evidence of blackened PCB. I shall update this thread in a while, but the M/Home gets little use from now on though.
Ive checked out M/H parasitic drain and once the tiny clock and immobiliser circuit fuse was removed, - there was NO drain. Im confident the solar panel (18 inches X 48 inches) is well up to preventing drainage and keeping immobiliser in use.