Battery status display

[Brianandjoy]

My battery status display keeps jumping from 80 to 70% I’ve given it a charge and now the leisure batteries display is jumping from 100 to 90% any ideas we’ve just had 3 days frosty weather.We are going away for 3 months how long can we ask our son to leave them on charge,the manual says 12 hours,c an you safely leave it on longer.The batteries are 2 years old

 

[ArunAlec]

When at home I leave mine on hookup permanently so I can run a mains dehumidifier from the mains socket. No different from being plugged in at a campsite.

 

[AlanC]

I leave our van plugged in for a minimum of 24hrs once every 4 weeks or so. You can leave the van plugged in for much longer with no ill effect, as Alec says, just like being on-site.

When the charger has brought the batteries to full charge, it drops down to a low current trickle charge. This is good as the trickle charge will help to de-sulfurise the plates thus preserving the life of the battery. I do the same with a separate charger for the engine battery too.
Alan

 

[TripleBee]

I do the same with a separate charger for the engine battery too.
Alan

Don't charge them at the same time. I did it once, and I got some strange effects, like heating starter battery and a strange current display to the leisure batteries.

Normally, when the leisure batteries are full, the inside charger will automatically start trickle charging the starter battery too, so no real use to charge the starter battery separately. But if you do, first disconnect the van from the mains.

 

[AlanC]

Don't charge them at the same time. I did it once, and I got some strange effects, like heating starter battery and a strange current display to the leisure batteries.

Normally, when the leisure batteries are full, the inside charger will automatically start trickle charging the starter battery too, so no real use to charge the starter battery separately. But if you do, first disconnect the van from the mains.

No, I do them each on different days for just that reason.

BTW, I believe formally the engine battery is not trickle charged by the onboard charge when on hook-up. It is apparently a quirk of the wiring that it gets a small trickle charge when on hook-up. Probably a small leakage current via the split charge relay.

Alan

 

[TripleBee]

I measured the starter battery once on a campsite after a few days on charge. The starter battery was about 13,xx V, so it certainly was being charged.
If I measure first day on charge, the starter battery is on normal voltage of about 12,6V, so not charged.

It is not much, but it helps. Anyway, it's better to get a decent charger to charge the starter battery, but not while the leisure batteries are on the mains.

 

[WelshGas]

No, I do them each on different days for just that reason.

BTW, I believe formally the engine battery is not trickle charged by the onboard charge when on hook-up. It is apparently a quirk of the wiring that it gets a small trickle charge when on hook-up. Probably a small leakage current via the split charge relay.

Alan

I measured the starter battery once on a campsite after a few days on charge. The starter battery was about 13,xx V, so it certainly was being charged.
If I measure first day on charge, the starter battery is on normal voltage of about 12,6V, so not charged.

It is not much, but it helps. Anyway, it's better to get a decent charger to charge the starter battery, but not while the leisure batteries are on the mains.

Can definitely confirm this is so, at least on my 2014 California .

Does the Mains Charger Charge the Engine Battery?

A question often asked. VW categorically say NO, it does not. However there is a body of Forum members that believe it does “ Trickle Charge “ the Engine Battery once the Leisure Batteries are Full. Proof. On site and I plugged in my 2 Voltmeters. Cheap and cheerful but they both under read by...

vwcaliforniaclub.com

 

[ArunAlec]

Can definitely confirm this is so, at least on my 2014 California .

Does the Mains Charger Charge the Engine Battery?

A question often asked. VW categorically say NO, it does not. However there is a body of Forum members that believe it does “ Trickle Charge “ the Engine Battery once the Leisure Batteries are Full. Proof. On site and I plugged in my 2 Voltmeters. Cheap and cheerful but they both under read by...

vwcaliforniaclub.com

My starter battery gets a trickle too! Confirmed with voltmeter.

 

[AlanC]

I don't doubt there is a trickle current passing into the engine battery when on hook-up.

My point was that this was not intended by design, more a happy accident but shouldn't be relied on to keep the engine battery healthy.

Alan

 

[marchugo]

The loading of the starter battery when on hook, is not a happy incident. The Cali is designed to give a 1 Ampere charge to the starter battery when on hook.

All the best from Amsterdam,

Marc.

 

[MattBW]

I measured the starter battery once on a campsite after a few days on charge. The starter battery was about 13,xx V, so it certainly was being charged.
If I measure first day on charge, the starter battery is on normal voltage of about 12,6V, so not charged.

It is not much, but it helps. Anyway, it's better to get a decent charger to charge the starter battery, but not while the leisure batteries are on the mains.

Yes and remember not to connect the negative to the negative terminal on the engine battery but to an earth on the body nearby. It can cause issues with the systems used to monitor the battery and bluemotion etc.

 

[TripleBee]

Yes and remember not to connect the negative to the negative terminal on the engine battery but to an earth on the body nearby. It can cause issues with the systems used to monitor the battery and bluemotion etc.

Well, I don't have that problem as mine is no bluemotion, but indeed, with start/stop you need to take body negative and not battery negative.