12V problem

Joined
Dec 7, 2017
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Location
Sherwood Forest, Notts
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51,592
MH
Carthago Compactline
Exp
Since 2017. Before had caravan, folding camper and various tents.
On a recent trip when not on hookup the 12V system kept switching itself off, around 7 times over a couple of days. It worked fine after switching it back on- until it went off again. The battery monitor indicated that the battery was at 100%. The dealer installed a lithium battery for me. I don't know if this has anything to do with it. It's been back to the dealer but I am not sure how thorough their investigation was. I think they may have just put it on hookup and it didn't drop out, which wasn't the problem.
Any suggestions would be most welcome.
 
What was the outcome of the dealer inspection? What electronics/control panel do you have? What was the original battery's total AH and what type? What is the new total AH?

I would have thought the charging and other systems would need to be altered or configured for Lithium if you have moved from another type, assuming you have done that i.e. a swap from old lead-acid batteries to new Lithium. Also, a change in AH may need a control panel re-configuration to ensure the real charge state/type of the new battery is reflected on the panel - if wrong, this "might" cause problems down the line if it "thinks" the battery is at a certain level and it isn't and then cut out. When you switch it back on, it sort of resets but then senses something is wrong again and cuts out again.

If it were the battery (still could be if it is "intelligent" and that bit is goosed) you'd probably be unable to switch everything back on again as you mention.
 
Thanks Andacami.

There was no outcome from the dealer inspection. I have to admit I have no idea about AH.
1629988969099.png

The control panel is this one.
 
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I would have thought if the dealer installed it they would have ensured you had all the relevant bits to go with it? And if they can not find a fault you need to persevere with them until they do? They have taken your hard earned for the job and it should work correctly? Take it back to them and insist that they try it off hook up for a longer period of time.
my other thought was are you using an inverter with it as this will cut off if battery gets below certain voltage and they may not have checked that?🤔
 
The battery monitor indicated that the battery was at 100%.
What battery monitor is it? Does it show volts and amps as well as amp-hours (Ah)?

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Someone more knowledgeable can maybe confirm or deny this but is the battery monitor suitable for lithium batteries? Traditional monitors rely on the decreasing battery voltage to estimate % of charge available, however lithium batteries maintain voltage until almost completely discharged so although it may say 100% it may not be anywhere near that.
 
It doesn't look like your batter monitor measurers amps or counts amp hours of charge/discharge.
If that's the case the percentage readout will be meaningless with Lithium if it is only calculating it from voltage reading as the voltage output is fairly linear until nearly discharged.

I think you need to check the spec on the battery and the settings on the charger & solar controller & B2B.
If you are not sure post the info on here and one of us should be able to check for you.
 
Someone more knowledgeable can maybe confirm or deny this but is the battery monitor suitable for lithium batteries? Traditional monitors rely on the decreasing battery voltage to estimate % of charge available, however lithium batteries maintain voltage until almost completely discharged so although it may say 100% it may not be anywhere near that.
It depends on the type of battery monitor. The simple ones just measure voltage, and deduce the state of charge from that. As you say, not brilliant for lead-acid batteries, and probably no good at all for lithium.

However the other type measures the charge into and out of the batteries. It continuously monitors the current flow (amps) ingoing and outgoing. With an internal chip to measure time, it can account for the amp-hours going in and out. If it's calibrated so that the amp-hours is correct when the battery is full, it is quite accurate.
 
Sensible ideas from funsters:; best advice is back to the dealer and have the sort it out and show you how it all works..
 
Sensible ideas from funsters:; best advice is back to the dealer and have the sort it out and show you how it all works..
Problem is the dealer probably won't have a clue a lot of them for electrical work get a contractor in.

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On a recent trip when not on hookup the 12V system kept switching itself off, around 7 times over a couple of days. It worked fine after switching it back on- until it went off again. The battery monitor indicated that the battery was at 100%.
Bear in mind we only know about your system from what you tell us. For example, a solar controller can get into a weird state, especially if the battery management system (BMS) switches the battery off for a time. Do you have solar?

Another thing you can do to help, both us and the dealer, is to get a multimeter and take some voltage readings at the battery terminals. You can get a cheap multimeter at any DIY shed for less than a tenner, and it's a great help to have on-the-spot readings at the time when things have gone wrong. It's easy and safe to take voltage readings with a meter on a 12V battery, if you're not sure let us know.
 
Bear in mind we only know about your system from what you tell us. For example, a solar controller can get into a weird state, especially if the battery management system (BMS) switches the battery off for a time. Do you have solar?

Another thing you can do to help, both us and the dealer, is to get a multimeter and take some voltage readings at the battery terminals. You can get a cheap multimeter at any DIY shed for less than a tenner, and it's a great help to have on-the-spot readings at the time when things have gone wrong. It's easy and safe to take voltage readings with a meter on a 12V battery, if you're not sure let us know.
Thanks. My brother in law has suggested the multimeter, and is going to use one to take the readings as you suggest.
 
We have the same panel as yours, and we had problems with the panel randomly switching off. It turn out to be the plug on the back was not fully "clicked" in. Maybe worth popping the panel out and checking, it is held in with spring clips so easy to remove.
 
My Compactline came with a CBE system which only monitors voltage. My lithium battery always registers as maximum voltage on the CBE panel.

You say the switching off happens only when you are not on a hook up. The CBE system will shut down if the voltage drops but this doesn’t seem likely with a lithium battery. Perhaps you have an occasional loose connection somewhere on the battery supply that causes the system to shut down from time to time. This would not happen when on hook up because the mains charger would keep the voltage up even if the battery supply was momentarily interrupted.

What make and model lithium battery have you got. The internal Battery Management System (BMS) might possibly shut the battery down briefly if it detected overheating or over voltage. Again you would not notice this if on a mains hook up.
 
Update. The dealer rang and asked me to download the Lifos app for Lifos 105 and when it goes off to tell him the readings. It went off overnight. The voltage showed 13.5 before and after switching back on.

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We have the same panel as yours, and we had problems with the panel randomly switching off. It turn out to be the plug on the back was not fully "clicked" in. Maybe worth popping the panel out and checking, it is held in with spring clips so easy to remove.
I can't see how you would remove it apart from pulling it and I would be a bit nervous about doing that
 
I think it would be worth talking to Lifos about the battery management system. I am wondering whether the BMS may very briefly interrupt the supply from time to time as part of it’s normal operation, possibly when it detects it is not being used. The reason I suggest this is that I have an Efoy fuel cell which does this. A different bit of kit so not directly comparable but it interrupts itself so that it can get accurate voltage readings. The Lifos battery has a built in battery monitor which you access through the app (great feature wish my battery had this), I am wondering if the battery very briefly shuts off when idle so that it can calibrate itself.
 
I think it would be worth talking to Lifos about the battery management system. I am wondering whether the BMS may very briefly interrupt the supply from time to time as part of it’s normal operation, possibly when it detects it is not being used. The reason I suggest this is that I have an Efoy fuel cell which does this. A different bit of kit so not directly comparable but it interrupts itself so that it can get accurate voltage readings. The Lifos battery has a built in battery monitor which you access through the app (great feature wish my battery had this), I am wondering if the battery very briefly shuts off when idle so that it can calibrate itself.
It could be something like that. As far as I can remember it has only gone off when idle. Not when TV, lights etc on.
 
I've got a KS Energy lithium with a bluetooth interface with a phone app that provides voltage, state of charge, charge/discharge rate plus individual cell voltages. My Compactline (Euro 5), same habitation panel, doesn't have a smart alternator, so no B2B installed. I've turned off the CBE charger and rely on 3x100watt panels through an Epever controller. This is configured for the lithium charging parameters. Not had any power cutouts - yet!
 
It seems that when the electricity drops out it leaves the warning W255H on the CP plus. I suspect this is a symptom rather than the cause though.

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It seems that when the electricity drops out it leaves the warning W255H on the CP plus. I suspect this is a symptom rather than the cause though.
That means no 12v to the heater but there must be some power for the CP plus panel to be active however it only requires a few milliamps.
 
That means no 12v to the heater but there must be some power for the CP plus panel to be active however it only requires a few milliamps.
Yes, although the heater is switched off.
 
That code on the CP panel will pop up when there is a brief interruption to the supply.
 
Hi - hope you don’t mind asking did you resolve this and if so how - I have a similar reset issue for no apparent reason - I was wondering if was temperature

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Y
Hi - hope you don’t mind asking did you resolve this and if so how - I have a similar reset issue for no apparent reason - I was wondering if was temperature
Yes. We had the lithium replaced by a gel battery.
 
Yes. They obviously didn’t know how to fit lithium to a Carthago.
I think I’ll just add a second gel now.
 
That was a bit drastic, was that the dealers advice?
Yes. They obviously didn’t know how to fit lithium to a Carthago.
I think I’ll just add a second gel now.
And did they offer a monetary refund, in line with the vast difference in price between the two types of batteries? ;) Please forgive me if my question appears to be somewhat sceptical, but I don't trust dealers of any shape or form, as more often than not, they haven't got a clue about what they are doing, but want to take your money and run. :mad:

Cheers,

Jock. :)
 
And did they offer a monetary refund, in line with the vast difference in price between the two types of batteries? ;) Please forgive me if my question appears to be somewhat sceptical, but I don't trust dealers of any shape or form, as more often than not, they haven't got a clue about what they are doing, but want to take your money and run. :mad:

Cheers,

Jock. :)
Oh yes. Full refund of the lithium and no charge for the gel.

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