Understanding Leisure Battery

Calibang · Jul 23, 2021

Hi All

Bit of a noob question regarding the batteries on my 2019 Ocean.

The issue is linked with the fridge. Once the battery is fully charged the fridge only stays on for a short while before switching off. If the engine is running, it stays on.

Checking on Control unit display the battery status is showing 80-90% but only 11.0V. When fully charged its shows 100% and 12.5V. This is the bit I am confused about. If the batteries are 8-90% charged, why would it only put out 11.0V (which is probably the reason why the fridge switches off). The lights etc all still work fine.

Does this means the battery needs replacing? If the batteries need replacing, is there somewhere better than main dealer or can they be replaced under warranty? The camper was relatively little used and neglected to charge up the leisure batteries especially during winter.

All help would be greatly appreciated.

Thanks

Wildcamper · Jul 23, 2021

If the batteries have been neglected and been allowed to discharge then that are probably knackered. If the dealer allowed this to happen then it should be a warranty claim, if the previous owner allowed this to happen then you are probably out of luck. You could try asking the previous owner to pay up but good luck with that one.

KernowMaid · Jul 23, 2021

Calibang said:
Hi All

Bit of a noob question regarding the batteries on my 2019 Ocean.

The issue is linked with the fridge. Once the battery is fully charged the fridge only stays on for a short while before switching off. If the engine is running, it stays on.

Checking on Control unit display the battery status is showing 80-90% but only 11.0V. When fully charged its shows 100% and 12.5V. This is the bit I am confused about. If the batteries are 8-90% charged, why would it only put out 11.0V (which is probably the reason why the fridge switches off). The lights etc all still work fine.

Does this means the battery needs replacing? If the batteries need replacing, is there somewhere better than main dealer or can they be replaced under warranty? The camper was relatively little used and neglected to charge up the leisure batteries especially during winter.

All help would be greatly appreciated.

Thanks

https://vwcaliforniaclub.com/thread...d-hold-a-charge-for-months-not-4-weeks.40523/
Hi I had a similar issue recently. Please see the thread. I had them replaced under warranty.

B J G · Jul 23, 2021

Battery Voltage Levels in Percentage terms

Calibang · Jul 24, 2021

Thanks Wildcamper - I concur with you, deffo need replacing.

@Kennowmaid, thanks for that. Besides need replacing, I still dont understand the 90% charged but 11.0v output? I guess if I replace them, all will be well?

I will try the dealer (dreading it) and see how far I get.

B J G · Jul 24, 2021

Calibang said:
Thanks Wildcamper - I concur with you, deffo need replacing.

@Kennowmaid, thanks for that. Besides need replacing, I still dont understand the 90% charged but 11.0v output? I guess if I replace them, all will be well?

I will try the dealer (dreading it) and see how far I get.

Dealer will have to do a full charge cycle then test before VW will accept a warranty claim.
Over 24 hour process.

Calibang · Jul 24, 2021

Thanks BJG thats one of the big issues for me. I can walk to my local VW (car) to have my Golf serviced but the Camper needs to go to a Van centre which isn't near or convenient. I dont mind dropping it off for a few days but its the issue of getting to and from (taxi I guess).

Just wondering if its more cost effective to replace them myself but judging by some of the prices on the forum, its a bit (very) steep!

Wildcamper · Jul 24, 2021

Calibang said:
Thanks BJG thats one of the big issues for me. I can walk to my local VW (car) to have my Golf serviced but the Camper needs to go to a Van centre which isn't near or convenient. I dont mind dropping it off for a few days but its the issue of getting to and from (taxi I guess).

Just wondering if its more cost effective to replace them myself but judging by some of the prices on the forum, its a bit (very) steep!

Our local VW Commercials comes and collects our van and then returns it once finished. I think this incurred a £10 charge.

B J G · Jul 24, 2021

Calibang said:
Thanks BJG thats one of the big issues for me. I can walk to my local VW (car) to have my Golf serviced but the Camper needs to go to a Van centre which isn't near or convenient. I dont mind dropping it off for a few days but its the issue of getting to and from (taxi I guess).

Just wondering if its more cost effective to replace them myself but judging by some of the prices on the forum, its a bit (very) steep!

Definitely try/exhaust the dealer warranty replacement first.
Dealer battery price will be well over DIY source & fit if not warranty.

G3WRT · Jul 24, 2021

B J G said:
Battery Voltage Levels in Percentage terms

View attachment 81904

G3WRT · Jul 24, 2021

I thought the fully charged battery should be 13.8V? I assume these figures mean there is a diode (0.6V) or more in series dropping the voltage. Anyone know the reason?

yossarian · Jul 24, 2021

G3WRT said:
I thought the fully charged battery should be 13.8V? I assume these figures mean there is a diode (0.6V) or more in series dropping the voltage. Anyone know the reason?

It comes down to resting voltage, under load voltage, and charging voltage and the chemicals in the plates. The figure you quote is likely charging voltage for a lead calcium battery with some sort of valve regulation (above ambient pressure internally.)

Modern sensors look at inter alia, the current, resting time, temperature etc and produce a higher finesse SOC estimate than the table above. Still guesswork though.