Thanks again but the
solar control seems to be working properly unless it is an intermittent fault with a twenty eight year old van anything is possible .
Intemittant fault on a brand-new van is possible, let alone a 28 year old one
As merl says, you can only get a high voltage on the
battery from something connected to it. i.e. a Charger.
You hadn't been driving it - so can't be the Alternator
You don't hook up - so it can't be the Mains Charger.
Only thing left is the
Solar Charger/Controller, so that is the area where you need to focus on.
You haven't told us what
solar regulator you have, so can't give any specific "check this" or "check that".
You *could* have a
battery equalization routine enabled on the controller which will intermittantly, but on a regular cycle put a higher voltage into the
battery for a short period. Some controllers will not do this, others you can programme to do this, others do it every nth charge cycle whether you want them to or not! The voltage you are seeing is on the high side for that routine, but not impossible (and also not desirable).
The voltage you are seeing can be around what a PV Panel may output, so you could have a connection from Panel to
Battery? maybe internally in the controller, maybe a stray wire strand on the connector making an intermittant connection? You could have a bad solder joint on the Controller PCB. maybe a slight overflow of solder that is making a connection randomly depending on movement or heat and shorting PV +ve to
Battery +ve.
To give an example of my own
Solar Controller, I was randonly losing power out to my Habitation Electrics (which are fed via the LOAD of the
Solar Controller) for a while. Couldn't really identify what was happening, but when doing some further analysis, it turned out that the
Battery was intermittantly disconnecting from the
Solar Controller and this was only apparent at nighttime as the Controller was harvesting enough to run the active 12V loads during the day (I would occasionally lose power in the day when there was a heavy cloud (hindsight info
). And when I was checking voltages, etc with my meter, it was all ok as the action of putting the probe on the
battery +ve and -ve on the controller fixed the connection temporarily, as the fault was (on closer inspection under a magnifying lens) a dry joint on the
Battery +ve terminal on the controller.
And this was a
Solar Controller only just over a year old, made by
Victron, so top quality kit. So be it old or new, bargain basement or top drawer, it doesn't matter, you can still have problems with a piece of kit!
(as an aside, Controller was replaced as
Victron don't tend to repair kit, but while waiting for the new one, fixed the faulty one in about 5 minutes with a iron and been fine since
)
