Basic battery charging in a T6 with a battery under the bonnet and one under the seat.

[cnl123]

Hi all. Thanks for allowing me on your forum.
I have recently bought a 2017 ex AA T6/T32. The battery (starter) has died and I am looking to charge it. Be aware that I have gone from a simple but very reliable T4 and although that was simple I am confused with how I can charge the T6. Do I just attach the charger leads to the bonnet battery and let it do its thing? Do I disconnect the battery (maybe both batteries) and charge out with the vehicle. The manual is not helpful as it just tells me to take it to the nearest VW dealer. They give no instructions as to how to get it to the dealer without a charged battery though. If I disconnect a battery will it mess up the onboard 'computer' ? Any advice to this matter would be appreciated.
Thanks

 

[Dellmassive]

Connect a smart battery charger with a AGM profile to the battery Red POS post.

But the Black NEG clamp needs to got to the vans chassis and not the NEG battery post.

 

[roadtripper]

See this recent thread

Newbie Hillside Starter battery charging question

Hi I am new to the Campervan world have recently brought a Hillside Birchover and now have it in storage for the winter. The starter battery voltage has now dropped to 12.2V so I am planning to charge the starter battery. The VW manual is useless in its advice for charging the battery stating it...

www.t6forum.com

 

[Dellmassive]

Battery Chargers - How I Did It -

Battery Chargers - How I Did It - So its that time of year again, cold, rainy. . . . . . . flat battery =[ This time we look at Battery Chargers. Our vans will most likely come with a AGM style starter battery, for this type of battery we need a "Smart Charger" . . . . but what does this...

www.t6forum.com

.

Battery Charging - Main Battery Chassis Point -

Battery Charging - Main Battery Earth Point - so weve all be told NOT to bridge out the battery monitor on the neg side of the battery when charging it. This is so the ECM can correctly gauge the SOC (state of charge) of the starter battery by monitoring the current flow in and out of the...

www.t6forum.com

.

Battery Monitoring -- How I Done It --

Battery Monitoring -- How I Done It -- Part #1 Battery monitoring is a very important part of your 12v system . . . . whether its just the vans starter battery or your leisure setup keeping an eye on the power in your battery bank will keep you from breaking down and make sure your weekends...

www.t6forum.com

.

 

[cnl123]

Connect a smart battery charger with a AGM profile to the battery Red POS post.

But the Black NEG clamp needs to got to the vans chassis and not the NEG battery post.

Thanks for the response. Could you please tell me why negative contact has to go to the chassis? Is it something to do with keeping the system info alive? Would I have to charge under the bonnet ? Or disconnect and charge out of the bonnet but near the vehicle. What are the implications of charging outside the van? Thanks.

 

[roadtripper]

The big block on the negative battery post is a shunt - it monitors charge into and out of the battery very precisely so the van (and the stop start system) knows the exact state of charge at all times. As everything needs to go through that lead it can see everything.

If you connect anything direct (load or charge) then it is not seen by the van and it will get the calculation wrong leading to electrical issues.

 

[Bigsidavies]

Thanks for the response. Could you please tell me why negative contact has to go to the chassis? Is it something to do with keeping the system info alive? Would I have to charge under the bonnet ? Or disconnect and charge out of the bonnet but near the vehicle. What are the implications of charging outside the van? Thanks.

If you remove the battery from the vehicle then you can just charge it as normal as far as I’m aware, with the pos and neg leads to the battery terminals. You don’t need to be near the van.

 

[roadtripper]

If it's off the van then you don't need to worry about the shunt. However you may find you get a chunk of warning lights when you replace the battery until all the electronics sort themselves out with a drive.

If you can get the charger under the bonnet it's a lot simpler and less hassle, just make sure you connect the ground to the other side of the shunt.

But either will work so do what's the easiest for your situation.

The picture of my battery is a 6.1 system but before I made a dedicated charging lead I connected the ground of the charger to the battery cable crimp here

 

[Dellmassive]

The big block on the negative battery post is a shunt - it monitors charge into and out of the battery very precisely so the van (and the stop start system) knows the exact state of charge at all times. As everything needs to go through that lead it can see everything.

If you connect anything direct (load or charge) then it is not seen by the van and it will get the calculation wrong leading to electrical issues.

View attachment 224151

yep - what he said.

 

[Dellmassive]

if you remove the battery from the van and chsarge it - the van "energy management syatem" - wont know its been charged.

and will go into a self learning program that can last for 15 drive cycles, where the stop/start is dissabled untill the van re assesses the battery SoC.

and as @Bigsidavies on a T6.1 you get a dash full of errors untill a few drive cycles where the sensors recalibrate.

....

@roadtripper shows a good point to clamp the NEG charger lead (on his T6.1)


+++++


D


I've added my own starter battery fuse box . . .



and picked up my own chassis ground.




and added my own Victron charger quick disconnect.





and thats were i picked up the feed for the battery monotors. . .





+++++++++++


your notice that VW copied us and added an additional fuse box at the battery on the T6.1 ( tongue n cheek comment as i done it before them as the T6 battery was very poor for adding additional circuits to the battery)


++++++++++


i run the Victron IP65 charger : Amazon.co.uk : victron charger 12v

the Victron quick disconnect : https://amzn.to/3NPCwfL

and the BM2 battery monitor : https://amzn.to/4aHqhM3



and if you want to add your own fuse box like mine : https://amzn.to/3H6wdAN


.

 

[Bigsidavies]

if you remove the battery from the van and chsarge it - the van "energy management syatem" - wont know its been charged.

and will go into a self learning program that can last for 15 drive cycles, where the stop/start is dissabled untill the van re assesses the battery SoC.

and as @Bigsidavies on a T6.1 you get a dash full of errors untill a few drive cycles where the sensors recalibrate.

....

@roadtripper shows a good point to clamp the NEG charger lead (on his T6.1)


+++++


View attachment 224157D


I've added my own starter battery fuse box . . .

View attachment 224159

and picked up my own chassis ground.

View attachment 224158


and added my own Victron charger quick disconnect.


View attachment 224161


and thats were i picked up the feed for the battery monotors. . .

View attachment 224160



+++++++++++


your notice that VW copied us and added an additional fuse box at the battery on the T6.1 ( tongue n cheek comment as i done it before them as the T6 battery was very poor for adding additional circuits to the battery)


++++++++++


i run the Victron IP65 charger : Amazon.co.uk : victron charger 12v

the Victron quick disconnect : https://amzn.to/3NPCwfL

and the BM2 battery monitor : https://amzn.to/4aHqhM3



and if you want to add your own fuse box like mine : https://amzn.to/3H6wdAN


.

View attachment 224162

Thanks for clearing that up Lee. I did wonder how it would know you now had a full battery.
So probably
Not the best idea to charge it away from the van then?
I’ve done it that way before so that I don’t have a cable trailing across the public pathway for a whole day as my van is parked on the street.

 

[Dellmassive]

Thanks for clearing that up Lee. I did wonder how it would know you now had a full battery.
So probably
Not the best idea to charge it away from the van then?
I’ve done it that way before so that I don’t have a cable trailing across the public pathway for a whole day as my van is parked on the street.

its fine to charge OFF the van,

just be aware of the vans process of testing the battery - normally higher rev`s for a while and start/stop will shows as disabled . . . I've noticed it can last for 15 drive cycles, a week, two weeks . . . whatever.

it keeps going untill the EMS decides that the battery is fully charged, and it assumes the previous SoH of the battery.


+++


that why you need to code in a new battery - to reset the SoC & SoH to 100%.


+++

 

[cnl123]

Thanks for all your input on this subject. I have a lot to learn and all advice here has cleared a lot of things up for me.
Another question: How does the auxiliary battery under the passenger seat get charged? In situ? Out of situ? Or is it just left to the alternator to work it's magic after the start/stop battery is fully charged? Also if charged within the vehicle (both batteries) are both the + / - leads still connected ?

Thanks

 

[roadtripper]

It depends what's fitted in your van, other ex AA van owners may be able to help if you are using what they fitted:

Team ex-AA van

Recently picked up my first van. So excited! now the spending starts do we already have an ex AA, or this colour yellow van thread?

www.t6forum.com

You'll generally fall into one of two ways of charging when the engine is running.

A split charge relay that engages when the engine is running so both batteries are charged as a pair. Very basic and relies on the two batteries being identical types, in a start stop system it also means they will never be charged beyond around 80% to leave room for regenerative braking.

A DC-DC charger that is basically a battery charger that runs off your van electrics. This will keep the two batteries isolated so the van charges and looks after the starter and the DC-DC charger charges and looks after the leisure battery (and just looks like a large load like a heated windscreen to the van when running)

DC-DC charging is considerably better with a start stop vehicle and also allows the use of different battery types, in particular modern LiFePo lithium batteries for much greater capacity, but they do cost more.

With either system you would be fine connecting a mains charger to the leisure battery to top it up - many vans have one permanently fitted as part of the EHU - the only possible exception is a genuine California which I believe also has shunts on the leisure batteries.