Mercedes Sprinter starter battery (s) (1 Viewer)

[BillandHelen]

Our new Mercedes starter battery behaves very differently than our old 2017 Fiat Ducati did. The Mercedes has a “smart” alternator and a “smart?” battery, actually it has 2 batteries, a starter and a secondary battery for some of the electronics. From new, when at rest it settles at 12.4/12.5v, according to my Votronic battery monitor and if you open a door etc it can drop to 12.1/12.2v before slowly recovering. It also “wakes up” regularly to check the electronic hand brake is on and run (I think) some diagnostics. It did sit at the dealers for 10 weeks before we could pick it up, so assume it went flat and was recharged.

it hasn’t caused me any problems yet, it always starts immediately, it’s trickled charged by our 120w solar through an mppt regulator. I got Mercedes to check it when it was in for its recall, they thought all ok, though don’t know what checks they ran, mechanic said a basic panel van would last about 3 weeks unattended, ours has alarm and tracker connected.

so, question is, is this normal with Smart alternator/Mercedes batteries? Seems a reasonably common question on Wildax forum? I don’t have a “battery master” fitted as we have lithium batteries, have read the other detailed thread on Votronic,cbe advising not to fit with lithium, that was same advice I got from Roadpro. Maybe I’m just worrying too much now that I can monitor the battery continually!!

Lenny HB , any advice?

 

[Brains]

I also have a Sprinter based vehicle, with much the same set up as you, except i do have a Battery Master fitted.

I'd suggest you talk to VanBitz.

You have a engine battery - basically to run the starter motor
You have a leisure battery to run the van electrics
You have a solar panel, which if a Battery Master was fitted, should trickle charge both batteries

See what VanBiz recommend, they have forgotten more about motorhome electrics than you or I will ever learn.

 

[gus-lopez]

At 12,4-12,5 v resting with solar on I'd say that the battery is being kept going by the solar. Might bean idea to disconnect & see how quick the starter battery dies?

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[69473]

Hi Bill and Helan just picked up your post and your situation is similar to mine.
From what i understand it's perfectly normal for the starter battery to loose charge within 3 wks.
Apparently this is because the vehicle electronics never really shut down completely due to the constant monitoring of the electronic handbrake .
If a vehicle stands for a prolonged period the manual suggests battery disconnection and chocking of road wheels, presumably because you will then have NO handbrake?
The MBUX information system is also power hungry, this can also be shutdown through the vehicle settings menu but will also deactivate other features such as the vehicle alarm.
I fitted a cheap Bluetooth tooth battery monitor to the starter battery purchased from ebay for £20, works well and will give advanced warnings of low charge.
I also have lithium leisure batteries but was told by the installer there wasn't a battery master available compatable with the mix of lithium and AGM?
One thing you may be able to help with, do you have an intermittent flash of the electronic handbrake warning light when the ignition if off.
I've noticed that every 5/6 minutes it momentarily flashes, presumably self checking?

 

[sparkyvanman]

Hi , this may sound as if I am a complete idiot but here goes. I have a Hymer A class 580B on a Mercedes sprinter chassis 2 years old . The leisure battery is under the floor easy enough to get to. But for the life of me I came find the engine starter battery! Does anyone know where it’s hidden. I know I should have got the dealer to show me at handover but there was a lot to take in. Am I the complete idiot or am I missing something?

 

[HarryML7]

Hi , this may sound as if I am a complete idiot but here goes. I have a Hymer A class 580B on a Mercedes sprinter chassis 2 years old . The leisure battery is under the floor easy enough to get to. But for the life of me I came find the engine starter battery! Does anyone know where it’s hidden. I know I should have got the dealer to show me at handover but there was a lot to take in. Am I the complete idiot or am I missing something?

Footwell passenger side ?

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[sparkyvanman]

Footwell passenger side ?

I did think about that but it means lifting the whole of the from rubber flooring and it’s fastened down in lots of places and does not look as though it’s meant to be lifted. I guess I should of asked the Mercedes commercial vehicle dealer who serviced it. I could ask the dealer I bought it from new but to be honest I don’t want to have anything more to do with them , such bad service.

 

[Boris7]

Under the passenger seat

 

[Boris7]

You have access points for jump starting under the bonnet

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[HarryML7]

I did think about that but it means lifting the whole of the from rubber flooring and it’s fastened down in lots of places and does not look as though it’s meant to be lifted. I guess I should of asked the Mercedes commercial vehicle dealer who serviced it. I could ask the dealer I bought it from new but to be honest I don’t want to have anything more to do with them , such bad service.

Is there not a mat inset in the floor mat? I seem to remember jump start connections under the bonnet therefore no need to access the batt for that reason.

 

[pappajohn]

My car has a smart alternator and the voltage varies, after a drive to town and back, between 12.2v and 12.4v. Most likely the electronics pull power before shutting down.
Stick a meter on late and it shows 12.6v.
When running its between 12.4v and 14.0.

 

[sparkyvanman]

Yes t

Is there not a mat inset in the floor mat? I seem to remember jump start connections under the bonnet therefore no need to access the batt for that reason.

Thanks for the reply, yes the is jump start connections under the bonnet , I guess if I ever need to charge the battery I could connect a charger to these

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[Boris7]

I feel stupid now, there’s a devise you can buy (as I was informed on here) that simply connects to the leisure battery positive and starter battery positive and either negative and when on hook up it looks after both batteries.

I bought and fitted one and never have an issue since, just can’t remember what it’s called or find the thread.

 

[pappajohn]

I bought and fitted one and never have an issue since, just can’t remember what it’s called

Battery master.

 

[BillandHelen]

Hi Bill and Helan just picked up your post and your situation is similar to mine.
From what i understand it's perfectly normal for the starter battery to loose charge within 3 wks.
Apparently this is because the vehicle electronics never really shut down completely due to the constant monitoring of the electronic handbrake .

thank you for your response. My tracker allows me to remotely monitor the battery, all is good at the moment, solar is keeping all batteries fully charged in this lovely sunshine, it’s winter I’m worried about. As discussed on another thread, there is a battery maintainer that has been designed to work with lithium, I’m getting this fitted next month by Roadpro, who fitted our lithium and inverter. I’m also going to get Mercedes to put in a new starter battery, about £200 and not under warranty, as the van sat at the dealer for 3 months under lockdown and battery went totally flat. Hoping combination of these 2 will solve the problem, if not then frequent driving or Mercedes recovery will be only options left!!
again thanks for response.

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[69473]

My battery 2020 Sprinter is under the rubber flooring in passenger footwell.
Battery monitor see picture from ebay."12V Battery Monitor Voltage Meter Battery Tester Analyzer by Phone Bluetooth | eBay" <Broken link removed>

 

[69473]

My lithium's were also fitted by Roadpro, due you know the brand name of the battery maintainer?

 

[BillandHelen]

Yes, it’s the Ablemail AMT-12, if you speak with either Andy himself or Allen Jenner they will sort you out. The unit is on their website now, if your handy fit it yourself, if like me, a 3 pin plug is a struggle, it is less than £150!!!

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[Brains]

solar is keeping all batteries fully charged in this lovely sunshine, it’s winter I’m worried about.

We have a solar panel, and our van is stored outside but in almost permanent shadow during the winter.
During this past winters long enforced lockdown at one point we did not even visit our van for 4 months.

The limited solar and Battery Master kept both batteries fully topped up and the van started first time.

As long as the electrobloc is switched off, the amount of power used by a few LED's the tracker, alarm and handbrake monitor a a few other bits is minimal. A few hours of feeble sunshine during the winter months seems to be enough.

 

[69473]

The issue with the newer Sprinter vans and battery drain relates to the MBUX system (10 inch screen) and power hungry electronics some of which never shut down completely, this is well documented on various MB car forums.
These vehicles are not designed to be left for prolonged periods of time, yes its nice to have all the tech and convenience of built in Bluetooth/wifi and internet access but it comes at a cost.
3wks with no additional battery charging will result in a flat battery.
I also suspect that some vehicles starter battery (AGM) performance will be compromised from new due to discharge in storage.

 

[Pausim]

From new, when at rest it settles at 12.4/12.5v

This is normal with a smart alternator. The ECU deliberately leaves room in the battery so that it can recover power when the vehicle is slowing down.

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[BillandHelen]

One year later and an update. Our issue was that the Mercedes electronics never really switch off, constantly checking the electronic hand brake etc, putting the starter battery under strain whilst in storage resulting in low battery warnings. We have a dual MPPT solar charger so things are fine between April/September but up her in Scotland not enough sun to cope over autumn and winter.
we installed an Ablemail 12 battery maintainer which has settings for lithium/smart alternator ( the only maintainer to have this I believe) which trickle charges when lithium over 13.3v and starter below 12.4v, this helped over autumn but in winter just no sun to set it off!!
Fellow funster Hoovie who sells Ablemail kindly offered to install me an override switch which “forces” the maintainer on and will allow me to manually control trickle charging. I’ll try this on site first to make sure it doesn’t deplete the leisure battery too much, I’m hoping it will cope with 2/3 weeks in storage. Fingers crossed this will solve it. Side benefit is should never have to use my mains charger for my lithium again.