Van Battery Issue

[Kperr02]

Hello,

My T6.1 starter battery shows as low (with a warning to drive the vehicle) after being at a campsite for ~4 nights. However, I can leave it parked outside the house for a few weeks & have no battery issue.

I’ve checked that there are no internal lights on in the cab (doors etc), but cannot figure out what is draining the battery.

The battery did go flat a month ago when I left the side lights on, but though I’ve had a quick google, the sites I’ve read suggest that the battery should not have been damaged (which would seem to be the case when I leave it outside the house for a few weeks with no battery issue).

Grateful for any advice,

Thanks.

 

[Dellmassive]

When camping every time you unlock/power up the van the lights come on and the modules power up..

if you open the van multiple times a day. . . . .

And if you leave the door open then the van will stay awake longer.

thats why the battery will go flat after 2 days or so.

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at home the van is parked and locked - so will last 4 weeks.

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when camping you need a EHU battery charger connected to the starter battery. . .

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

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or if off grid,

look at taking some mobile solar with you.

100-200w should help extend your camping duration.


more info here:

[Guide] Mobile Solar Panels ? . . . - How I Did It -

Mobile Solar Panels ? . . . - How I Did It - There is loads of background to this . . . . . but for now here is a vid for you all. =] Just remember W = V*A and as a general rule a good 100W panel will give you up to 6A charge with good sun. 25w = 1.5A 50W = 3A 100w = 6A 200w = 12A 300w = 18A...

www.t6forum.com

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and here:

Dellmassive’s "How I Done It" blogs.

-- Dellmassive`s -- "How I Done It" -- thread -- ************************************************** Dellmassive`s -- "how I Done It" -- Thread ************************************************** Kit List And Stuff -- How I Done It & What I Use --...

www.t6forum.com

.

 

[Martinf]

In our experience the vehicle battery is the T6 Achilles’ heel when used as a camper. Dellmassive explains why.

We have greatly reduced the problem by doubling the installed solar panel capacity and installing a solar charger that will automatically charge the vehicle battery under set conditions. We use an NDS SunControl2 but I’m sure there are others. As a post -build install it’s a bit of a hybrid, being installed in parallel with the original leisure battery charger, but works well for us.

In reserve, we carry a separate vehicle battery charger.

 

[bobbybasic]

- Change all your interior light bulbs to LED's.
- Switch off the overhead cab light.
- Then fit one of these:

AMT12-2 Trickle Charger charges Vehicle Battery from Leisure Battery with Solar Charger /Mains Hookup | Ablemail Electronics

The AMT12-2 has many names Trickle Charger, Battery Maintainer, Battery Saver, Reverse Charger, Top Up Charger, Battery Equaliser, but its purpose is to keep a Source / Vehicle Battery charged & protected from damage during prolonged periods of Vehicle, Boat & Motorhome inactivity or storage...

www.ablemail.co.uk

 

[SAJO]

For the interim until I get any of these solutions sorted I'm using solar powered trickle charge that I used for my motorbike, probably not as powerful as these solutions but with the current sun were having its appears to be helping nicely.

 

[R&RK]

Hi all, we have a similar problem on our T6.1 Highline, March 2023 vintage. With the van parked up without use, we get 9 days from full charge (12.6v) to the low voltage warning (11.7v). Been back to VW but they declared there is not a problem with the battery, they suggested driving it more often. Plots from BM2 attached. The BM2 is set to lead-acid battery as I can't see any indication on the battery of type, no label or part number visible with the battery in-situ. As it's not a daily driver, it's a nuisance having to keep it charging the whole time, much quicker to drain when camping, doors open etc, adds an unwelcome stress to camping.

I have two questions;
Is there any way of telling what type of battery is fitted and if currently an ESB, would upgrading to AGM help to extend the life?
Is 9 days about right for full to flat or does that suggest a problem?

 

[Dellmassive]

Looks like, after a drive, it's dropping below 12.0v within 3days.

So something not right.

Either the battery needs a full charge.

Or.

Something is draining the battery.

Or.

The battery is knackered.


Can you try connecting to a EHU charger for 24hrs to get a full charge in....then retest for a week.


.

 

[Dellmassive]

Post a picture of the starter battery and van....

Have you got any 3rd.party electrics wired up?

How often does it get driven?

 

[R&RK]

Hi Dellmassive, thanks for responding and also for your previous posts on these issues which have been interesting & helpful.

I think the battery was fully charged at the end of the day on the 16th or at least, as fully charged as it ever gets. We had returned from a trip away and had been driving for 3 hours. I have added a plot showing 14th Feb, the van had been charging for over 48 hours by that point, (using a Ring RSC612 smart charger, bought in a panic on a previous camping trip with warning messages on the dashboard). We then drove from 12ish until 3pm and camped, without charging the vehicle, for a couple of days. Voltage seemed to drop to 12.5V as soon as we stopped driving and then, with doors opening and closing etc, voltage dropped to around 12v by the morning of 16th when we set off to get back home. After another 3 hour drive, we arrived home at 6pm and the BM2 reported 12.6v.

Do you think the BM2 should be set to AGM battery type, would that give more accurate voltages? How can I tell what type of battery is fitted?

Would it be worth buying a Victron charger instead of the Ring?

We bought the van, professionally converted in July last year and have been having these problems ever since, to be fair to the converter, we get similar results if we disconnect the leisure system so I don't believe there is any problem from that side. Surprised when VW declared there is no problem.

I should have said that we have a tracker on the vehicle which presumably consumes power when the van is asleep.

Prior to reading your earlier posts, I had been charging the battery using an old style of charger, not a smart one, might that have caused problems? VW didn't mention any problem with the battery but I haven't had that independently checked.

It's too dark to take photos now and I am away for the next couple of days but will send photos later this week. Nothing connected across the terminals other than the BM2 and I use a body ground when charging, thanks to your previous posts.

Thanks for your interest so far, will be in touch latter half of this week.

 

[R&RK]

Hi Dellmassive,

Sorry for the gap in the messages. Taking this forward, my Ring charger stopped working so for the past month or so, I have used a Victron blue smart charger with quick disconnect so it is easier to use. I've had a poke about in the engine compartment and found its a Moll EFB+ battery.
Our van is a March 2023 T6.1 highline, not a daily driver, too precious for that!
It had a tracker fitted as part of the conversion (Global Telemetrics S5 + Immobiliser) which is powered by the vehicle battery system, not Leisure, it will consume power all the time.

Photos below;
Battery with top cover removed, only BM2 monitor connected to battery negative post
Busbar showing connections to leisure system (disconnecting these makes no different to the battery life) and Victron disconnect
Victron quick disconnect, positive connected to busbar, negative to chassis ground point (thanks for your earlier posts on this)
Plot from BM2 showing full charge 2nd March 13.3v (battery on charge for 4 days), dropping to 12.11v by 9th March with the van locked and left alone.

Then something hopefully interesting - we had a 5 day trip away last week for which the leisure system was reconnected and we didn't charge the vehicle battery other than by driving each day. The plots from BM2 show;
5 day driving plot shows battery charged to 13.3V before we set off 2nd April, camping in the van each evening/night so doors open & closed etc, van hooked up to electric supply each evening to charge leisure (only). Driving for 159 miles on day 1, only got 12.7v when we stopped, charging only from the vehicle alternator, less on subsequent days when we covered less distance.
6 April plot shows our return journey, starting at around 12.1v, we drove for 5 hours or so, covered 250 miles but the vehicle only charged the battery back to 12.7, nowhere near the 13.3 we get from the Victron Smart Charger. Haven't shown the plot for today but at 18:00 on 8th April, we're back down to 12.33v.

The conversion that we had professionally done has added a Victron lithium battery for Leisure, with an Orion DC-DC smart charger, the converter has checked the settings on the DC-DC charger to make sure it isn't draining the vehicle battery or taking supply from the alternator, he's happy with the settings.

We are getting other minor electrical issues, a couple of fuses blown and the submersible water pump or tap stopped working after 2 months so I am wondering if there could be a common fault underlying all of this.

I would appreciate your thoughts on whether;
The Moll battery is likely to be defective, VW have checked it and declared it OK.
There is likely to be a parasitic drain somewhere draining the vehicle battery when the vehicle is parked up (other than the tracker)
The alternator isn't working effectively as not charging the battery above 12.7v.
Any other thoughts/tests you can suggest.

Would greatly appreciate any suggestions, keen to focus the search if possible.

Thanks for reading this far.
Kind regards, Richard.

 

[roadtripper]

As a general observation the MOLL EFB batteries have a bit of bad reputation, they have not been very reliable. You might want to consider moving to an AGM battery.

If you are a 6.1 then you will have Start Stop so remember that your van will generally only charge to around 80% (it leaves capacity to do regenerative braking) but the Victron will charge to 100%

If your 12.7 figure is from a point the battery is reasonable unloaded then that would be about that region - an EFB battery follows an AGM voltage profile.

I assume your start stop is functioning? (It's a good sign of general health of the system) your smart alternator appears to be, hence the spikes of near 15v charging

 

[TallPaul_S]

The alternator isn't working effectively as not charging the battery above 12.7v.

Unfortunately, it's actually working exactly as designed...

See here for a full explanation

[Guide] DC-DC Charger (for leisure battery) -- How I Done It --

But in short, T6 and 6.1 have 'smart alternators' which, due to emissions and fuel consumption reasons, only charge the starter battery (and factory leisure battery if fitted) under braking, or when headlights etc are on.

As a result, to allow for charging under braking etc, it will only ever charge the battery to around 80% or 12.5/12.6v - as your seeing. The only way to get the battery to a full charge is to use a mains charger, or trickle charge from a DC-DC charger.

Also remember it takes an hour or so for the battery to settle after being charged, and volts will drop if you unlock it, so take any reading with the van locked and at least half a hour after turning the engine off.

Looking at your graphs, there's definitely either a drain or the battery is knackered.

Here's mine on a T6



12.4v after a 25 min drive from work, 5 and a half days later with zero driving and it's only dropped to 12.24v.

 

[roadtripper]

Let's run some numbers. In your March plot you got to about 55% charge using the AGM values, and I suspect your starter is 70Ah like mine.

So that means, assuming full capacity, you've lost 38.5Ah of capacity over 7 days. That's 5.5Ah per day.

That's an average current of 0.23 amps

That's not actually a huge amount it's not inconceivable that a tracker could do that, it does feel a bit high.

However in normal driving your capacity is going to be lower as it may only be charged to about 80%

Ideally in a conversion things like trackers and dash cams should run off the second battery

 

[Dellmassive]

Looks like you have a problem, the starter battery is being drained at a constant rate.

It's running flat over 7days.

Id assume the tracker may be the cause, but possibly other items as well?
Usb charger? Dashcam?... Anything else non OEM installed?

To test you can pull the fuses for the tracker for a few days, then plug back in for a few days... Then post the bm2 plot.

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...

 

[Dellmassive]

You can also get a clamp meter to trace the power leak, like this.....

Clamp Meters

Any recommendations for clamp meters? They have been mentioned in a few threads but I can’t find suggested products. Suitable for small mA measurements with dc in the van and elsewhere and also if possible up to mains ac. I’m not sure how much I need to spend for a tolerably decent one with the...

www.t6forum.com

....

 

[R&RK]

Gents, thanks for your responses, been really helpful to rule out some theories. No other non OEM connected other than tracker, don’t know how that is powered so will take it back to the converter and ask them to investigate. Will post a further message when I have an answer. Thanks again.

 

[DXX]

Batteries are like live in partners, you don’t notice the gradual reduction in performance until you get a new one.

 

[Bigsidavies]

Is it worth just getting rid of that crappy Moll and getting a decent higher capacity 95ah AGM.
I replaced mine earlier this year for about £140.

 

[roadtripper]

Is it worth just getting rid of that crappy Moll and getting a decent higher capacity 95ah AGM.
I replaced mine earlier this year for about £140.

My vote would be yes. I know the cost isn't trivial but if you are having weird unexplainable electrical issues starting from a known good battery can often solve things.

 

[R&RK]

Thanks chaps, good call and might come to that, will let the converter check it out first though as it’s still under warranty. Keen to find if there is something causing a drain as that would affect a new battery too. Any recommendations for a brand of agm battery and is it a case of the largest capacity that can fit? Current Moll is 70 ah, 95 seems like a decent upgrade, what sets the upper limit on capacity?