Battery Issue??

[J8mes]

Hi All,
2919 T6 T28 Camper.
My battery voltage always seems to be around 12.2 to 12.3 when checked and engine and ignition off. Always thought should be 12.6v.
When I turn ignition on drops to 11.5 ish.
When engine running its between 13.6 and 14.4.

Now my limited knowledge would suggest the battery is not fully charged.
A mobile VW tech ( out for another issue) suggested this was normal for the VW smart charge system.
I on the other hand think something is not quite right.
Had van for 10 months from new and not actually had any issues starting even if left for a couple of weeks.
Anyone got any suggestions to this being normal or something being a mis?

 

[Nigel W]

Mine is the same. I think the battery management system limits the base charge of the battery at 80% charge so that there is room for a dump of power into the battery during regenerative braking.

 

[J8mes]

Mine is the same. I think the battery management system limits the base charge of the battery at 80% charge so that there is room for a dump of power into the battery during regenerative braking.

Hi Nigel,
Thank you for the reply, seems to make sense. I just worry that in the winter if I don't use it for a couple of weeks I get a no start issue

 

[Nigel W]

We think along the same lines as mine doesn’t move for months on end. I bought a little Noco 5 amp charger which I plug into the cig lighter once a week and that keeps it nicely topped up.
happy to send you details if you want?

 

[J8mes]

We think along the same lines as mine doesn’t move for months on end. I bought a little Noco 5 amp charger which I plug into the cig lighter once a week and that keeps it nicely topped up.
happy to send you details if you want?

Hi Nigel,
I bought a Noco GB40 to keep with the van, as I don't yet trust the van .
Think we definitely think alike!

 

[Nigel W]

Hi Nigel,
I bought a Noco GB40 to keep with the van, as I don't yet trust the van .
Think we definitely think alike!

I don’t like to use jump starters so I use one of these below with the adapter to go into the cig lighter - just keeps the battery topped up

NOCO GENIUS5UK, 5-Amp Fully-Automatic Smart Charger, 6V And 12V Battery Charging Units, Battery Maintainer, Trickle Charger, And Battery Desulfator With Temperature Compensation: Amazon.co.uk: Car & Motorbike

NOCO GENIUS5UK, 5-Amp Fully-Automatic Smart Charger, 6V And 12V Battery Charging Units, Battery Maintainer, Trickle Charger, And Battery Desulfator With Temperature Compensation: Amazon.co.uk: Car & Motorbike

www.amazon.co.uk

NOCO GC003 X-Connect 12V Dual-Size Male Plug Accessory For NOCO Genius Smart Battery Chargers: Amazon.co.uk: Car & Motorbike

Buy NOCO GC003 X-Connect 12V Dual-Size Male Plug Accessory For NOCO Genius Smart Battery Chargers at Amazon UK. Free delivery on eligible orders.

www.amazon.co.uk

 

[Pete C]

Mine is much the same (2016 model) with the original battery. No issues with starting after 4 weeks in the depths of winter.

What I do, if I know it is going to be left for some time, is fully charge the starter battery with a charger before I leave it.

Pete

 

[J8mes]

Mine is much the same (2016 model) with the original battery. No issues with starting after 4 weeks in the depths of winter.

What I do, if I know it is going to be left for some time, is fully charge the starter battery with a charger before I leave it.

Pete

Cheers Pete, good idea.

 

[J8mes]

I don’t like to use jump starters so I use one of these below with the adapter to go into the cig lighter - just keeps the battery topped up

NOCO GENIUS5UK, 5-Amp Fully-Automatic Smart Charger, 6V And 12V Battery Charging Units, Battery Maintainer, Trickle Charger, And Battery Desulfator With Temperature Compensation: Amazon.co.uk: Car & Motorbike

NOCO GENIUS5UK, 5-Amp Fully-Automatic Smart Charger, 6V And 12V Battery Charging Units, Battery Maintainer, Trickle Charger, And Battery Desulfator With Temperature Compensation: Amazon.co.uk: Car & Motorbike

www.amazon.co.uk

NOCO GC003 X-Connect 12V Dual-Size Male Plug Accessory For NOCO Genius Smart Battery Chargers: Amazon.co.uk: Car & Motorbike

Buy NOCO GC003 X-Connect 12V Dual-Size Male Plug Accessory For NOCO Genius Smart Battery Chargers at Amazon UK. Free delivery on eligible orders.

www.amazon.co.uk

Looks good!

 

[Nigel W]

Just one last point, look at your vehicle battery. The left hand post has a cover over it - lift this and check that there is only one connection to this post.
The converters sometimes use this terminal and they shouldn’t.

 

[J8mes]

Just one last point, look at your vehicle battery. The left hand post has a cover over it - lift this and check that there is only one connection to this post.
The converters sometimes use this terminal and they shouldn’t.

I'll check that later, i have a funny feeling there is a fused wire coming from the positive terminal.

 

[VanDamMan]

Hi All,
2919 T6 T28 Camper.
My battery voltage always seems to be around 12.2 to 12.3 when checked and engine and ignition off. Always thought should be 12.6v.
When I turn ignition on drops to 11.5 ish.
When engine running its between 13.6 and 14.4.

Now my limited knowledge would suggest the battery is not fully charged.
A mobile VW tech ( out for another issue) suggested this was normal for the VW smart charge system.
I on the other hand think something is not quite right.
Had van for 10 months from new and not actually had any issues starting even if left for a couple of weeks.
Anyone got any suggestions to this being normal or something being a mis?

Wow your not Dr Who ...Time traveller. “2919” T6... sorry ...back to the present your battery sounds fine ...it’s the stop/start 80% regeneration thing......but during lockdown I used solar to trickle charge service battery once the leisure was full using Ctek 250 ..
Dashcams may cause a slight battery drain and if you leave it standing for prolonged period perhaps Try a trickle battery charger

 

[Big.mac]

I'll check that later, i have a funny feeling there is a fused wire coming from the positive terminal.

That isn’t necessarily a problem. Most likely it is a feed to a DC-DC charger if you have a leisure battery fitted.

 

[J8mes]

Wow your not Dr Who ...Time traveller. “2919” T6... sorry ...back to the present your battery sounds fine ...it’s the stop/start 80% regeneration thing......but during lockdown I used solar to trickle charge service battery once the leisure was full using Ctek 250 ..
Dashcams may cause a slight battery drain and if you leave it standing for prolonged period perhaps Try a trickle battery charger

Thanks for the info, much appreciated. Didn't notice the typo

 

[J8mes]

That isn’t necessarily a problem. Most likely it is a feed to a DC-DC charger if you have a leisure battery fitted.

I'll try and check that out.

 

[Nigel W]

I'll check that later, i have a funny feeling there is a fused wire coming from the positive terminal.

Positive is ok it’s the negative on the left with the cover on which shouldn’t be used. My battery to battery charger was connected to both terminals causing Vehicle battery charging issues, the negative has to be moved to a body earth point.

 

[Bruntonpasty]

Positive is ok it’s the negative on the left with the cover on which shouldn’t be used. My battery to battery charger was connected to both terminals causing Vehicle battery charging issues, the negative has to be moved to a body earth point.

Can I ask why? Surely the battery earth is connected to both the vehicle body and the gearbox casing? The same? Happy to be shown the error of my ways..

 

[Pete C]

No. The battery negative is connected to the vehicle body through a device which measures current flow, to help determine the state of charge of the battery. If you connect directly to the battery negative terminal, then you bypass this device, and the vehicle becomes unaware of any current flow through that new cable.

Pete

 

[Bruntonpasty]

Thanks, I did not know that. Everyday's a school day....I'd like to see a CFD for that.

 

[Nigel W]

Can I ask why? Surely the battery earth is connected to both the vehicle body and the gearbox casing? The same? Happy to be shown the error of my ways..

Have a read of this post - it’s very informative

Starter Battery Wiring - VW Disagreement

Interesting one. I've had a few problems with my starter battery discharging (its a Varta, not a Moll so thats not the issue!). Basically my battery goes flat after around 5-7d inactivity. Thats pretty short imo. This was an issue before lockdown and is not just due to the extended hiatus. I've...

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