Additional batteries more info needed

Brianandjoy · Apr 24, 2019

We had our additional batteries replaced last year under warranty as they weren’t holding charge even though nothing was running,we charged them up over winter admittedly not for 12 hours at a time but they had at least 5 or 6 hours every month.We are having trouble getting them to hold 100%.As soon as you disconnect the mains it shows 100% but this soon drops to 90%.Using the van over Easter we drove 4 hours but the batteries only showed 90% charged.They dropped 10% a day with just the fridge running and small amounts of lightning and water pump use.Is this normal.How long should the batteries last with light use.When we drove home about 6 hours journey they held 100% for 24 hours then dropped to 90% just parked outside the house.Is this normal.

johnyboy · Apr 24, 2019

We are similarly light users - 10% a day is pretty good really.
I read somewhere on the forum that driving (alternator charging) will not truly charge them to 100% such as the hookup does so I wouldn't be concerned with immediate drop on return drive

BenPcaliman · Apr 24, 2019

I believe when driving they will only charge to 90%. Hook up every month at least for 24hrs or get a solar panel. Works really well mine does from camper solarsolutions

WelshGas · Apr 24, 2019

Brianandjoy said:
We had our additional batteries replaced last year under warranty as they weren’t holding charge even though nothing was running,we charged them up over winter admittedly not for 12 hours at a time but they had at least 5 or 6 hours every month.We are having trouble getting them to hold 100%.As soon as you disconnect the mains it shows 100% but this soon drops to 90%.Using the van over Easter we drove 4 hours but the batteries only showed 90% charged.They dropped 10% a day with just the fridge running and small amounts of lightning and water pump use.Is this normal.How long should the batteries last with light use.When we drove home about 6 hours journey they held 100% for 24 hours then dropped to 90% just parked outside the house.Is this normal.

With everything OFF, what voltage and current draw does the Control Panel show?

Do you have anything plugged into the 230v Inverter socket on the bottom of the B pillar behind the front passenger seat?

Lift up the flap on the Inverter socket, see above, do you see a Green light On , top Left, under the flap?

MattBW · Apr 24, 2019

That is correct the bluemotion technology will only allow the alternator to charge them to about 80%, it has to leave some capacity for the regenerative braking etc. The control panel should show if you have power being used with everything off as WG says above.

The charging indicator isnt 100% accurate either and the control panel will also use some power over time. When you first stop the batteries will show 100% because of the output of the alternator, its only after an hour or two that the battery will settle and you will get an accurate idea of its resting charge.

Brianandjoy · Apr 24, 2019

There’s no green light on under the inverter flap,with the display panel on battery status it reads -0.2A,is that just the current drawn on the display panel?does The internal heater power come from the engine battery or additional batteries.Thanks for all the help so far

Loz · Apr 24, 2019

remember to turn the control panel off (as opposed to standby) with a second press of the off button. This will stop the drain from the control panel itself.

WelshGas · Apr 24, 2019

Brianandjoy said:
There’s no green light on under the inverter flap,with the display panel on battery status it reads -0.2A,is that just the current drawn on the display panel?does The internal heater power come from the engine battery or additional batteries.Thanks for all the help so far

The Diesel Parking Heater runs from the Leisure Batteries.
The 0.2amp current draw on the Control Panel is normal while the Control Panel screen is active and drops to 0 when the screen shuts down or the Control Panel is switched Off.

Brianandjoy · Apr 24, 2019

You mention a second press of the off button,is that the one beneath the diesel heater,I’ve only been pressing it once o turn the screen off,should I press it twice

TripleBee · May 2, 2019

Yes, the newer cars (and vans) don't charge the batteries full while driving. The generator will only charge now and then, the other times it will only give 12,2 - 12,5 V. So never suspect to have fully charged batteries, not even the starter battery.

To turn your display off, press the on/off button (left under), if nothing happens, press it again. Then the display will go black. If you press that button again, and you can directly see the information on the screen, it was not turned off. If you see the VW logo showing up, it was completely off.

My batteries are always fully charged because I (happily) don't have bluemotion technology. Although they say that I could save about 0,5 liters of diesel per 100 km. Don't know how that will be possible with my rather low consumption (6,5 - 7,5 liters/100km). And I have the 6 speed gearbox instead of a 5er with much too long 4th and 5th gear. It is now already struggling sometimes when the road is going up.

MattBW · May 3, 2019

It saves a little fuel in theory by disengaging the alternator when not required and reducing engine effort very slightly in practice no idea.

MartG · May 3, 2019

Do all new vehicles come with bluemotion, ie, the 'BMT' in the spec?

Sorry for the hijack but still awaiting my new Ocean... Talking of fuel saving, does the 'coasting' option make sense? I though it was certainly frowned upon (not in full control), although the dsg would cut in immediately I guess if throttled up. The car would use fuel to keep it running while coasting - my understanding was 'normally' the car cuts fuelling while engine braking downhill?