HELP NEEDED. battery drain

[S m w]

Hi everyone
Just having some problems with my both my batteries with regards to voltage levels
Let me explain my scenario
I have a Swift Motorhome 2019 model
In storage at present a 100w solar panel fitted and a battery master fitted by van blitz last September
When checking my voltage every few days via my Swift command app
The batteries are losing so much power it’s now down to 8v on each battery
I’m not sure why so much drain on battery
As far as I know the only power on is the PSU.( power supply unit ) which needs to be on for me to get readings from the app
I have a factory fitted tracker as well fitted surely that doesn’t drain to much ?
And because of lockdown I can’t visit the storage site to sort out the issue and now concerned that I will kill off the batteries and they will need replacement at the end of lockdown
Any ideas?
thanks
Steve

 

[Kannon Fodda]

If the batteries are down to 8V they are totally flat. No way will they recover just from the 100W solar. 10V can be regarded as flat for lead-acid, 12V would just about be a 50% charge, fully charged probably some 12.6V or more.
Every probability you will now need to replace the batteries. Any time they are flattened risks damage so they won't hold a good charge.
At this time of year 100W solar will often give a negligible charge. Even a sunny day you won't get much. 80W is about the best I've achieved with my van on the drive. Any app that is running, even for monitoring will use something, as would trackers, alarms and other stuff. My Victron Shunt is suggesting a draw of around 0.3mA. That is going to add up over time.

 

[Phill D]

Wow, 8v on each battery then you are probably lucky to get a response for your devise that is sending you the signal for your app.
the problem with solar this time of years is that on good days even if you get a meaningful charge it will be for such a short period it will not be useful.
if that 8v is accurate then sadly its likely the batteries will be shot if not already very soon.

how long has the van been parked up?

 

[S m w]

Hi phill D
The van has been in storage for only about 4 weeks now
When visiting the storage site before we had 12.8 on each battery when we took it for a 10 mile ride when we were in tier 3 so couldn’t go to far
Steve

 

[S m w]

Think next winter before I leave it for a few weeks I’m gonna isolate the vehicle battery via the key switch on steering column and turn off fully the Sargent power supply unit
And not use the phone app don’t want same issue every year

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[Phill D]

Hi phill D
The van has been in storage for only about 4 weeks now
When visiting the storage site before we had 12.8 on each battery when we took it for a 10 mile ride when we were in tier 3 so couldn’t go to far
Steve

4 weeks appears a short period to drop 2 batteries to 8v a piece. E.G. if you leave your car for a 3 week holiday its likely to have sufficient to start it when you return.

suggest something is really dragging it down, as you cant get near it there is not a lot you can do or check, but it would be interesting to find out the drain you are getting with the set up you have.

 

[S m w]

Yeah you could be right I’ve been thinking that too seems a lot in a short time of battery drain
May need to look into further when I am allowed to after lockdown
Thanks for your advice
Steve

 

[Trevor Wbm]

Newbie here, but is it not odd that both batteries are suffering? I've managed to flatten the leisure battery by leaving a light on in the loo, but surely the starter battery should be isolated?

 

[Phill D]

Newbie here, but is it not odd that both batteries are suffering? I've managed to flatten the leisure battery by leaving a light on in the loo, but surely the starter battery should be isolated?

he has a battery master set up in simple terms that trickles to the cab battery when needed so as the cab battery takes load it is replaced by the hab battery until they both Die!

the idea is that you always have sufficient cab battery to get you going..... but not in these circumstances.

 

[S m w]

As far as I know the tracker system runs off the starter battery as well
But could be wrong so some drain could be coming from that and insufficient sunshine last few weeks for solar power

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[Phill D]

I still think 4 weeks to drain 2 batteries to 8v each is quick.

 

[rosalan]

You have a Radio, Tracker and no doubt a Thatcham device all ticking over in mid winter. All dragging the battery down. Even a 100w solar panel will struggle to give any juice with the sun low down on the horizon so not able to help, always assuming there are no shadows on it.

 

[Jasz]

I doubt if your Swift will be the same as our Autotrail, but I once discovered that our battery had run down due to the heating fan still running in storage. It appears that it is deliberately wired from the permanent supply!
We were lucky and our battery survived and is still ok 2 1/2 years later.

 

[DuncanMcD]

I'm no expert but think your batteries will be ok once you can get them out of the vehicle and on charge. (I had one far lower than that, and the post above also sounds encouraging.)
Disconnecting the batteries when in storage works well I've heard. Obviously you'd have to be aware of any insurance implications. If you haven't got a battery charger use this time to search around for one, then you don't have to pay a lot for a brand new one.

 

[the1andonly]

To drain 2 batteries in 4 weeks sounds like more than the drain from a tracker. Ive had a 100w panel maintain 2 batteries in the past. You may need to trace the source of your drain before sacrificing 2 new batteries. A simple way to measure the current is to use a DC Clamp meter. Work out whatis drawn from each battery and by what. Pulling fuses or measuring voltage drop across a fuse will indicate the circuit, then safest method to measure current is to use a dc clamp meter ( shall i say that a 3rd time) no have a picture instead

This model can also be used to measure Voltage.

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[BlackIce]

Not an expert on this but sounds like you either have a fault causing a power drain or the cab battery is already failing. We have a 100W solar feeding the leisure battery and a Sterling battery to battery charger trickle charging the cab battery. The van has a tracker and alarm but the battery voltage has only dropped from 12.7v to 12.4v in the last 6 weeks despite the van being in shade most of the day.

 

[Kannon Fodda]

A 10 mile run is unlikely to have put much charge into the batteries if they were already part depleted. Initially when you switch off the gauges may show a high voltage, from the charging process, but you need to look again half hour or so later to see the true resting voltage. Very simply if you have a 100AH leisure battery and it was half discharged (50AH left), and in ideal circumstances your setup allows a 30A max charge, your going to need a couple of hours of running. Unless you have a B2B fitted the standard charging system in a motorhome won't be doing even that - The Sargent system in my Autotrail had a max of 12A.

 

[S m w]

Thanks for all your advice guys
Much appreciated will be checking out your ideas. So my problem won’t happen again
Cheers
Steve

 

[Compactliner]

One of the issues will certainly be the Sargent PSU which will undoubtedly 'managing' some sort of 'smart charging'....in fact it will be taking far more charge to run than is being generated by the solar panel...
Just look at the AutoSleepers owners forum and this is one of the hottest topics in winter...
Folk think smart charging will keep all batteries up....no.
However, they also want their trackers, alarms, monitoring apps all working...
A way round the Sargent 'hunger' is to turn it off, solar should then default to just the leisure battery (depends on which PSU you have) and then isolate the cab battery which should then stay up (but no immobiliser/alarm?) and not call for a top up via the BM.

 

[S m w]

Yeah compactliner your right
When the batteries are replaced I will do what you have suggested
They ( dealerships) never tell you all the information you need it’s surprising how much the PSU does drain the hab battery when left on to use these modern app’s
Summer is fine but winter is a different story even with solar