Solar Panel and electrical issues.

[yamyam]

Good morning campers from a wet but warm south west France. Having had good replies for previous questions I’ve decided to start a new thread to eliminate cross commenting. And as I mentioned before, after all this cr*p has finished and any campers are heading our way, mail me and we could meet up or give you a free overnight stay during your travels.
We have a Burstner 2007 T625 . Following problems with our leisure battery and what was thought to be parasitic discharge, the battery was changed for a new Exide AGM. Problems persisted with battery discharging what appeared quickly when not on EHU.
when on EHU and solar, on unplugging the EHU all power lost and control panel needed resetting. Disconnected the solar panel and checked across the terminals to find the input voltage was rapidly fluctuating fro 17v to 5v then 17v again . Shouldn’t this input remain constant? With solar disconnected, all problems seem to have resolved so wonder if the control box on solar requires attention. One further question please, no EHU or solar, should the battery discharge from 12.7v to 12.5v over 24 hours, what should battery voltage stay steady at if everything ok, and what voltage should the battery be recharged at please, before any damage can be done?

 

[autorouter]

Reconnected solar controller and panel in the order suggested. Battery began charging immediately and reached 13.7v

Battery charging is a chemical reaction that can take several hours. The only thing indicated by that 13.7V is that the battery is being charged. It is definitely not an indication of how charged the battery is.

The chart in post #23 is only valid with no charging and no load, after allowing several hours to settle. At this time of the year (mid-June) with solar connected, there will probably never be a long enough no-charge period for this to be valid. Some would say that's a bonus, but don't get too concerned about the detail of the voltages.