Engine battery flat

[steviej]

A few days after a 200 mile drive I found my engine battery was completely flat. I don't appear to have left anything switched on. I put my Cali on mains hook up, but after 24 hours charging the auxiliary battery's the engine battery was still flat and showing 4 volts across the terminals. I connected an external battery charger to the engine battery last night and after 12 hours the vehicle started this morning. I am puzzled as to why putting the van on hook up didn't charge the engine battery, or doesn't this work if the battery is completely flat?

My Cali is 3 years old, what is the life expectancy of the engine battery? any advice would be appreciated.

 

[Californiaman]

I think the semi 'official' life of a modern car battery is 2-5 years. In my experience, where older batteries used to seem to give a warning before failing modern ones work perfectly, right until they fail catastrophically.

My money would be on a failed battery.

 

[briwy]

Looking at the wiring diagram and description there is no provision for charging the starter battery from the hook up.
The only connections between the starter battery and leisure batteries appear to be through the voltage sensing isolation relay (via a fuse) that charges the leisure batteries when the engine is running.
I guess either the battery has had it or there is a problem with the alternator/charging circuit.
Does the battery hold it's charge now that it's been charged? If so then it would point to an alternator problem. Try checking the starter battery voltage with the engine running and see if it increases, it should be around 14-14.5v if it's charging OK.

 

[Martin]

Facelift should charge all three batteries when on hook up .. Mine does on a 60 plate

 

[briwy]

Wiring diagram here

Hope this helps

 

[Californiaman]

Yes, my facelift does too - 3 years old - I guess it may not be a facelift...

 

[steviej]

Thanks for your responses.

I took my Cali down to SMG Cowfold this morning and they tested the starter battery and alternator and gave them a clean bill of health The alternator was charging at 14.26 volts. Also the starter battery draw with with all equipment off was 0.036A which is normal.

So I am none the wiser as to what caused my flat battery, but will be carrying a jump starter on my next trip away. I was also told that the facility to charge the starter battery while on mains hook up was for "top up" rather than replenishing a totally flat battery.

Once again, a great service from SMG Cowfold.

 

[calikev]

I think you are right the hook up would only trickle charge the van battery
I only noticed a couple of volts difference between being hooked up and not
To much to ask for it to charge a flat battery

 

[murray0710]

I had to replace the battery on mine at 14 months. Had done some long trips day before, tried to start next day, totally dead. Called VW assist out (rac), confirmed battery was useless and had to get a new one fitted.

 

[John]

Hi Stevie,

just to clarify your starter battery should be trickle charged when on mains hook up.

This was not the case for the early Classic T5 Cali's up to 2007, which is why the training manual and circuit diagram, in the above post, shows that only the two leisure battery's are charged from mains hook up.

The training manual was written to help VW technicians with the introduction of the first Classic T5 Cali's, and has not been updated.

A fully charged starter battery should be showing around 12.5 V, when a voltmeter is connected across it. With the mains hookup connected to your face-lift Cali I would expect the voltage to increase to around 13 V to 13.5 V.

If this is not the case you have a fault in the, starter battery, mains hook up charging circuit.
It could even be as simple as fuse but may be more complicated.

Hope this helps.

John

 

[volksvans]

If you have a Kenwood Nav fitted it will drain the battery more than the standard unit due to can bus adaptors etc.....it is quite simple to wire this into the leisure battery...

 

[steviej]

Thanks John for your advice. I connected a voltmeter across the stater battery (fully charged) and got 13 volts. I immediately put my van on mains hookup and tested again and still got 13 volts across the starter battery. This might explain why putting my Cali on mains hookup did not put anything back into a flat starter battery.

Any idea which fuse I should check?

 

[John]

Thanks John for your advice. I connected a voltmeter across the stater battery (fully charged) and got 13 volts. I immediately put my van on mains hookup and tested again and still got 13 volts across the starter battery. This might explain why putting my Cali on mains hookup did not put anything back into a flat starter battery.

Any idea which fuse I should check?

Hi Stevie,

I have not got the workshop manual on my computer at the moment so sorry I can not help.

Perhaps Stu (another Mod) may be able to help or you could send a PM to Alex at SMG.

John

 

[KernowLad]

If you have a Kenwood Nav fitted it will drain the battery more than the standard unit due to can bus adaptors etc.....it is quite simple to wire this into the leisure battery...

I flattened ours on a campsite thanks to using ours a bit much (CDs to get the kids to sleep!). Luckily it bump started fine.

 

[estresao]

Do someone knows whether a Cali Beach (2015) also charge the main battery when on hook up?

 

[Bigted]

A 2015 bench will trickle the starter battery when plugged in.

 

[WelshGas]

You can leave the sidelights on one side on if you switch off the ignition with the indicator stalk on. R then sidelights on R side on and vice versa. This can flatten the engine battery after 48 hrs or so.