MY2017 Vehicle battery flat after a few weeks

[MikeB]

As others have noted, these modern vehicles don't like not getting used! And the battery manages to discharge over a few weeks. Well, ours was utterly discharged having not been used for 3 weeks, and is now showing low voltage after only standing a week, and this after being charged and then a nice run. It's a Varta, and was new 3 years ago curtosy of the original Moll being one of the "faulty ones" and replaced by VW under warranty. I accept that it's almost certainly been damaged as a result of not being used, but are there any thoughts / tricks to try before biting the bullet and just having to replace it?

On that note, what recommendations do the assembled throng of experts have for a replacement? Clearly, capacity is a Good Thing, but also resilience to irregular use.

 

[Pete C]

When you say “low voltage”, what is the actual voltage ?

Also, do you have anything non OEM attached to the battery or 12v outlets ?

Pete

 

[Pete C]

Also, never forget that if you charge the battery fully, then take it for decent drive, the battery will have less charge at the end than when you started the drive, due to the way the smart alternator works.

Pete

 

[Dellmassive]

The easiest / cheapest way to prevent that problem in future is to just connect up a smart charger once a fortnight and let it charge for 24hrs.

having a modern smart charger connected 24/7 is fine will keep the battery 100%, - if you can have the van connected to EHU 24/7.

if not then a good overnight charge every other week will be good.

but,

allowing the battery to drop low or flat will reduce its life expectancy and will not recover after a charge.

more in the charger side here -

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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if you have a leisure battery or solar see here - [Guide] Battery Maintainer (for Starter battery) -- How I Done It --


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and if you need a new starter battery, see here - Upgrading Starter Battery - how to guide



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[Qnapper]

For a few years now, I have been using a Sterling Battery Maintainer and to date never had a problem with vehicle battery even after leaving parked for 6 months. There are others out there, but trust Sterling stuff.

Battery Maintainer

Instruction Manual PDF Product Information PDF Battery maintainer / charger includes 1m of cable.Save money on batteries and stop them from being destroyed by discharging. A flat battery means you need an expensive replacement.The auxiliary battery charger maintainer is simple to install and is...

sterling-power.com

 

[MikeB]

When you say “low voltage”, what is the actual voltage ?

Also, do you have anything non OEM attached to the battery or 12v outlets ?

Pete

11.4 yesterday, after standing a week. That being after a nice overnight charge and a decent run. It struggled this evening. There's nothing running in the background, that I know of. Certainly no dashcam, tracker or similar. The van is a full conversion, but we turn everything off on the "leisure side" of the conversion when it's stood unused. (So fridge is off, even though that runs off the leisure batteries anyway)

 

[Pete C]

Ok, sounds like the battery is knackered.
Ours happily lasts 4 weeks on a full charge, and that’s nearly 5 years old.
As mentioned above, the key is keeping it topped up by a charger regularly.

Pete

 

[MikeB]

The easiest / cheapest way to prevent that problem in future is to just connect up a smart charger once a fortnight and let it charge for 24hrs.

having a modern smart charger connected 24/7 is fine will keep the battery 100%, - if you can have the van connected to EHU 24/7.

Thanks for the links - very impressive work if I may say so.

As it happens, the conversion has a charger built in, so yes, that's probably the best method. And it's how I charge if necessary, even to get it started when the battery decided to flatten completely. Unfortunately, it's a royal pita to run the cable to the van! But I accept it may well have to be the solution - other than using the wagon more often

Or putting solar on it.

 

[Dellmassive]

Thank you @MikeB

Take a look at the battery monitoring thread......

You will be able to see what's going on with your 12v system.

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

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I'd recommend two of the BM2 Bluetooth battery monitors, one on the starter and one on the leisure battery.

You will be able to track your battery levels from your phone and have a calendar history.


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[AussieMick]

Some camper conversions have a 240v battery charger that only charges the leisure battery not the starter battery also.
This is how mine is.

I have a separate 240v smart charger for my starter battery .

My leisure battery is connected to the onboard charger 24/7 and the starter battery is connected weekly or so until smart charger says it full.

Many assume the onboard charger will charge both batteries but its worth checking as your starter battery may be getting no charge at all.

I agree a battery monitor is the way to go as you can see exactly what is going in and out of your batteries and can charge when required.

Remember for a long battery life a battery, agm etc like to be kept at full charge as much as possible.

 

[CAB]

Carista left attached? Seems to drain mine quicker when I forgot to take it off.

2 weeks from 12.9 to 12.0v for me is normal, just alarm and tracker.

Small dash solar in the summer slows it down but doesn't keep it level, but then we are using it more frequently.

CTEK MXS 5.0 for a day every fortnight during the winter.

 

[MikeB]

Take a look at the battery monitoring thread......

Yet more awesomeness. I hanker after the days when I could fix my LandRover with a 1/2 spanner and a 5 lb lump hammer. It all went to hell when I had to buy a 13mm spanner - - -

And these days ye can't even change a battery without a computer!!!

 

[Dellmassive]

Lol.... Yep.

If you like that..... Here's the rest.

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

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[MikeB]

Some camper conversions have a 240v battery charger that only charges the leisure battery not the starter battery also.
This is how mine is.

Yes - there are lots like that it seems - ours charges both. I can't recall which it prioritises, but possibly the vehicle battery as I don't bother with a jump off another vehicle, just plug the van into the mains and it'll start happily enough. We've been out today, an hours drive each way. The leisure batteries are reading 12.6 and the van battery is 12. I'll take a trip to Halfords this week and get it tested I think.