Flat Battery

The solar panels keep my batteries in trim but I still give the MH a run about every four weeks just to keep the mechanicals in fettle. Whilst I wouldn't say it is a "transport of delight" from a driving point of view, it still makes a pleasant day out for a picnic.

agree with CY, regular use of the MH will keep things ticking over and bring any issues to your attention straight away....

re: :solar panels....the other advantage (in fact their raison d'être) is to give more freedom to choice of parking/site, allowing longer away from the requirment to hook up if thats your style....hreat for aires, temp hol sites, CL etc....

good luck. 

I have just been down to our motorhome and the vehicle battery was flat. We last used the MH on 9th December so it's only been 4 weeks. Since this happened to us last February I have connected the solar panel charger to the vehicle battery as well as the leisure battery. It has been OK over the summer and autumn months. I would have thought that it would have been ok for 4 weeks. The leisure battery is fully charged at around 14 volts according to the built in voltmeter. The vehicle battery measured 12.8 Volts until the ignition was turned on , then it fell to 12.2 volts. Everything looked ok, waited for the heater plug symbol to go out and tried the starter but nothing there, just dragged everything else down.

The base vehicle is a Peugoet boxer with 1.8 litre diesel engine. Vehicle was registered in May 2017. There is a battery standby system whereby you push a red button by the ignition key, turn the key to  BATT position and the battery is supposed to go into standby after about 7 minutes. This is supposed to isolate everything except the ECU memory storage, but I don't believe it works as last time I used it the clock and radio stations had to be reset, but not this time. I wonder if it has anything to do with adding the vehicle battery to the solar panel charger, although this has been alright for a shorter period of 3 weeks during the autumn.

Has anyone any suggestions. Thanks.

the 14v voltage at the leisure battery will be the raised voltage from the SP. a full rested battery should be 12.6 or 12.7v.

as you are not seeing an equivalent at the vehicle battery, I'm guessing no charge from the SP is being applied...could this be the case?

is this a self installed system, do you have a twin channel regulator set to disburse charge to both batteries?

the voltage at the vehicle battery of 12.8 'may' be the raised solar voltage but it's possible the starter battery is diff and not capable of holding that applied charge.....so it's actually flat.....hence the non starting.

i would get the cab battery tested.

what is the make of the conversion....AS by any chance?

When you buy a motorhome with a solar panel (usually 60 Watts minimum) it comes set up with a charge controller which balances the power to both leisure and engine battery. Sometimes you can adjust the charge priority and/or the percentage to each battery. As you have set this up yourself you need to be aware of the options and how they are set. Your cab battery should not have failed after less than 2 years so maybe the charging regime is incorrect.

There is of course much less sunlight at this time of year and the charge available will be substantially lower.

The solar panel controller is a Truma SDC10. It has 2 outputs and the default is Battery 1 (habitation) 50% and battery 2 ( vehicle) 50%. When I connected the vehicle battery to output 2, I changed the setting (for winter) to 20% for habitation and 80% for the vehicle. The battery type is set to AGM. The leisure battery is a Yuasa L36 AGM Plus, 12 Volt, 96 Ah, 850 A.  The vehicle battery is 12 volt, 95 Ah, 680 A (EN2/SAE) I cannot see the manufacturer or model as the label is hidden.

The base vehicle is a Peugeot Boxer and the conversion is Elddis.

you could disconnect the cab battery completely....then fully charge it with a seperate smart charger and then leave it for a few hours...

it should still be retaining its 14.6 or 14.7 volt full charge level.

if it has fallen away then it's not able to hold charge.

as in my earlier post, it may well be that the voltage you saw at the battery (14v) is the solar panel voltage....normally a rested battery would not have a charge this high...

i would do some tests in the cab battery to check its fine before doing other things...

AGM batteries require a different charging regime. Not sure how one system setting can be correct for cab battery (not AGM) and habitation battery (AGM), still, these systems are complicated and if it was installed that way then I guess it’s right.

Presumably it is still under warranty so a trip to your dealer seems the best way to get it resolved.