I had an auto electrician look at my system the other day,. Charged me £213 for what he purported to be 1.5 hours work which so far as I can see was very little but pronounced all OK except
solar panel not charging. Looked at it myself and my multi-meter gave me 8.5volts (no sun at that point) from the charger (Juta 10 MPPT). I tried reading the manual but it has been translate from the Chinese or whatever by a non native English speaker and is incomprehensible to me. The charge light (red) is flickering which seems to be saying that the
battery is fully charged. Any comments? please.
Battery low light is off and load light is steady on and green. Will 8.5 volts help charge the
battery if it does get low or do I need new
solar panel?
any comments? even if he did a full1.5 hours of work, £213?? I definately used to charge way too little
8.5V will do nothing in terms of charging. When there is daylight, the typical "12V"
solar panel will output around 20V if not connected and between 16V-20V in operation (numbers are approximate).
This is typical of what you might see on a meter with the panel connected and disconnected (I can fake a disconnected panel with a
Victron controller by turning off the charger)
Disconnected (so no charging)
PV - Charger OFF by
David, on Flickr
And connected (and charging)
PV - Charger ON by
David, on Flickr
There is an interesting video from
Victron explaining why when the voltage is too low from the PV Panel, you will not only not be charging the
battery, but actually using the
battery power to run the controller - so instead of the PV helping the
battery, it is draining it! On the
Victron controllers, they don't even turn on until the PV voltage is >5V MORE than the
Battery voltage.
Have a watch of this ... it is not just relevant to
Victron kit.
If it were me, I would be making breaks in the circuitry and checking voltages with my meter to see what the voltages are at various points and noting them down. Once you have the info, be easier to try to make sense of what is happening.
If you ARE getting 8.5V from a disconnected
solar panel, it is knackered (or maybe very dirty?)