Another low engine battery.

Casper46

Casper46

Joined
May 4, 2015
Posts
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Location
North Yorkshire
Funster No
36,190
MH
A Class
Exp
since 2000
We have a one year old Carthago C Tourer. This morning my Mercedes Me App told me that the engine battery was dangerously low. Until 2 days ago it was out in the sunshine and the solar was keeping on top of things. It has been inside its garage since then. The Victron Shunt is showing hab battery 100%, engine 12.1. We have plugged in EHU and the Sterling maintainer is now putting power into the engine battery. Is that the only way to top up the engine battery other than charging the battery directly, and why would it only hold up for such a short time?
Everything is turned off as far as we can tell.
Thoughts please.
 
Fitting a Battery Master should keep your starter battery topped up from your hab battery, mine does, or is your starter battery goosed.

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Van Bitz Battery Master — Offgrid Power Solutions

BATTERY MASTER, LEISURE > ENGINE BATTERY CHARGING SYSTEM THE AUTOMATIC ENGINE BATTERY CHARGING SYSTEM WORKS EVEN WITHOUT A MAINS HOOK-UP!
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Casper46 said:
We have a one year old Carthago C Tourer. This morning my Mercedes Me App told me that the engine battery was dangerously low. Until 2 days ago it was out in the sunshine and the solar was keeping on top of things. It has been inside its garage since then. The Victron Shunt is showing hab battery 100%, engine 12.1. We have plugged in EHU and the Sterling maintainer is now putting power into the engine battery. Is that the only way to top up the engine battery other than charging the battery directly, and why would it only hold up for such a short time?
Everything is turned off as far as we can tell.
Thoughts please.
Click to expand...
One year old? Should the battery still be within warranty?
 
It could be an alarm that is draining the battery. Toad alarms and some others gradually deplete the engine battery. I leave a small solar panel on the front, clipped directly to the engine battery and it keeps mine topped up without hookup.
 
ECU, immobilisers, alarms and trackers are all taking engine battery power even when you think everything is turned off. Sometimes the radio will also be taking power, in the case of Panasonic ones it can be more than a little bit if it hasn’t been fully shut down and has just turned off with the ignition.
 
If you have no solar input then fitting a battery master will only maintain the starter battery until the leisure battery is depleted so may not be the solution in this case maybe a small folding solar panel on an extension lead to daylight
 
Two on Tour said:
Fitting a Battery Master should keep your starter battery topped up from your hab battery, mine does, or is your starter battery goosed.

10% off with your Funster discount.
offgridpower.solutions

Van Bitz Battery Master — Offgrid Power Solutions

BATTERY MASTER, LEISURE > ENGINE BATTERY CHARGING SYSTEM THE AUTOMATIC ENGINE BATTERY CHARGING SYSTEM WORKS EVEN WITHOUT A MAINS HOOK-UP!
offgridpower.solutions offgridpower.solutions
Click to expand...
I am getting one fitted tomorrow at the same time as the bigger lithiums are fitted
 
I think the Sterling maintainter only keeps the starter battery topped up if the leisure battery is above 13.3 volts.

I use a Sterling Power B2B which keeps the starter battery topped up no mattter what the leisure battery voltage is.
Works flawlessly. ;)

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Two on Tour said:
nobody has given a plausible explanation of why a Battery Master is not. :unsure:
Click to expand...

I think that eddie has in the past explained why it is ok.

The BM will feed the starter battery provided that there is a 0.7V (or thereabouts) delta between the two batteries.

Ian
 
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LithiumConvert said:
Quite possibly because the lithiums stay at a higher voltage than lead-acid.
Click to expand...

Look at the bulk charging, absorption and float voltages and for FLA and AGM. (y)

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Two on Tour said:
Never quite got why the Ablemail is better if you’ve got lithiums, and nobody has given a plausible explanation of why a Battery Master is not. :unsure:
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All I can say is that two people I know in Scotland had batteries going flat in the winter with a BM one of them got through 3 starter batteries. In both cases fitting an Ablemail cured the problem.
 
Lenny HB said:
All I can say is that two people I know in Scotland had batteries going flat in the winter with a BM one of them got through 3 starter batteries. In both cases fitting an Ablemail cured the problem.
Click to expand...

Not exactly what I would call conclusive evidence of why the Ablemail is better than the Battery Master without details or is Scotland the defining factor. :unsure: :giggle:
 
Lenny HB said:
I did say "all I can say is"
Scotland in the winter raining, sod all solar.
Click to expand...

The Ablemail charges with a 3s pulse of 3a in ever 15s whereas the Battery Master is a constant 1.1a, so what am I missing as to what is being delivered to the starter battery between the two ?
 
As I see it there are a few different scenarios depending on your circumstances:
Do you want the starter battery to be trickle charged only when your lithium is full and solar is generating or at all times inc indoors (while the lithium battery still has enough charge) ?
Do you want the starter battery charged to 12.8V or more, or a bit lower as I understand a smart alternator does?
It can depend on where you leave the van, how long for, lithium capacity etc.
 
Mleabon said:
The Battery Master is good but it can't work miracles. Eventually both the leisure and vehicle batteries will go flat if there is no charging over winter.
Click to expand...

LiFePO4 batteries have very low internal losses. Sure, if you leave them long enough they’ll go flat but for most folks your scenario is very unlikely.

Ian
 
Lenny HB said:
All I can say is that two people I know in Scotland had batteries going flat in the winter with a BM one of them got through 3 starter batteries. In both cases fitting an Ablemail cured the problem.
Click to expand...
All I can say was they were fitted incorrectly

In hundreds of Lithium installations the Battery Master works perfectly

Mind you, the number of ‘non faulty’ Battery Masters that were returned, with absolutely nothing wrong with them belied the virtually zero failure rate we, and other professional installers experienced when installed correctly

However, I’m retired and have no axe to grind, either way, if it were a problem I’d say

But it isn’t
 
Mleabon said:
The Battery Master is good but it can't work miracles. Eventually both the leisure and vehicle batteries will go flat if there is no charging over winter.
Click to expand...
Really!

Next you’ll say perpetual motion doesn’t exist ;)

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Casper46 said:
We have a one year old Carthago C Tourer. This morning my Mercedes Me App told me that the engine battery was dangerously low. Until 2 days ago it was out in the sunshine and the solar was keeping on top of things. It has been inside its garage since then. The Victron Shunt is showing hab battery 100%, engine 12.1. We have plugged in EHU and the Sterling maintainer is now putting power into the engine battery. Is that the only way to top up the engine battery other than charging the battery directly, and why would it only hold up for such a short time?
Everything is turned off as far as we can tell.
Thoughts please.
Click to expand...
The new sprinters are notorious for pulling the cab batteries down. We only have a tracker fitted, but the engine managemnet is live all the time, constantly checking the electric handbrake amongst other things. Ours pulls out around 15 amps a day but the battery master keeps it going while the Lithium hab battery is kept up.There is a way to shut the system down through the MBUX but I have never worked out how to do it.
 
I’d add to this, I designed it to keep our customers engine batteries charged up over Winter, that’s it’s only function I’m my mind

I didn’t care if anyone bought it, in fact the first version was the good old days before the internet so we didn’t bother to retail it at all, as people would buy it, install it badly, or incorrectly and then drip about writing to MMM as the knew what they were doing as they used to work for the AA :doh:

Then the internet started so we re designed and re designed making it waterproof, dust proof, vibration proof, idiot proof, literally connect it up the wrong way, it will sulk and turn off, not playing until the fault is rectified. It is virtually bullet proof

However, not idiot proof so we would still get calls saying that a Battery Master was fitted ten years ago when they bought the van new, and they’d been told they needed a new engine battery and “what are you going to do about it “

Apparently congratulate them that the engine battery lasted 10 years wasn’t what they expected to be told lol
 
bigtwin said:
LiFePO4 batteries have very low internal losses. Sure, if you leave them long enough they’ll go flat but for most folks your scenario is very unlikely.

Ian
Click to expand...
I think you have forgotten the scenario involves the lithium being discharged via the BM.
 
bigtwin said:
LiFePO4 batteries have very low internal losses. Sure, if you leave them long enough they’ll go flat but for most folks your scenario is very unlikely.

Ian
Click to expand...
Not really. Lots of people leave their motorhomes over winter then post on forums asking why their battery has gone flat .

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