Lithium battery issue (1 Viewer)

[camperblast]

Hi there,
A lithium battery was installed on my camper a few years ago but the camper remained in storage ever since.
Many would probably say that the battery is now dead as it staid plugged for quite some time.
Now I got the camper out again and I was wondering if there was any risk in charging the battery now?
I plugged the main to the camper and turned on the battery so that it starts charging, but disconnected it a few minutes later as the switch board started smelling “hot”. I suspect it is ok and just due to the high current being drained while charging due to the fully depleted battery, but I thought I’d ask people here to be safe before plugging it back.
I also have a solar panel and I would not want to cause any damage to it either.
Any advise would be very much appreciated.

 

[James-Alex]

Don’t have lithium but would advise possibly best to take out van and charge properly on an external charger.

 

[cmcardle75]

If it was completely disconnected and started off pretty full, it's probably still charged even after a couple of years.

If it had any parasitic loads, the BMS should have disconnected the battery when it ran down and then it's luck of the draw if it can be woken up again. Waking requires a charger that will apply voltage even if the battery is showing 0V, as the BMS will have cut the battery off. That might require a special mode on the charger.

If it was a poor install without a BMS, it could be dangerous.

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[cmcardle75]

If it was completely disconnected and started off pretty full, it's probably still charged even after a couple of years.

If it had any parasitic loads, the BMS should have disconnected the battery when it ran down and then it's luck of the draw if it can be woken up again. Waking requires a charger that will apply voltage even if the battery is showing 0V, as the BMS will have cut the battery off. That might require a special mode on the charger.

If it was a poor install without a BMS, it could be dangerous.

Actually just spotted that you had solar. If everything was turned off, but the battery and solar left connected, that would typically be enough to keep it fully charged indefinitely even with a few small parasitic loads.

 

[camperblast]

If it was completely disconnected and started off pretty full, it's probably still charged even after a couple of years.

If it had any parasitic loads, the BMS should have disconnected the battery when it ran down and then it's luck of the draw if it can be woken up again. Waking requires a charger that will apply voltage even if the battery is showing 0V, as the BMS will have cut the battery off. That might require a special mode on the charger.

If it was a poor install without a BMS, it could be dangerous.

Thanks, the battery is completely depleted, but as soon as I turn it on (with the camper connected to the main), it starts charging. I also have an app that goes with that system and confirm that it is charging (from 0%).

 

[Just smiffy]

Lithium will suck as much energy as the charger can throw at it, if the charger is not up to it it could over heat so keep an eye on it….
If you have solar why hasn’t that kept the battery topped up….?

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[camperblast]

Lithium will suck as much energy as the charger can throw at it, if the charger is not up to it it could over heat so keep an eye on it….
If you have solar why hasn’t that kept the battery topped up….?

The camper was in storage. So kept in the dark.
How would you suggest to keep an eye on the charger?

 

[Just smiffy]

The camper was in storage. So kept in the dark.
How would you suggest to keep an eye on the charger?

I’m assuming your in the van or have it on charge at home… checking now and again…

 

[camperblast]

I’m assuming your in the van or have it on charge at home… checking now and again…

No, I am on a campground and was going to turn the battery unit on so that it can get charged over night

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[Raul]

Hello camperblast,
If the battery is very discharged, you have to bring it up very slowly, with a very low charge rate, much slower than your on board charger.
The best is with the solar charger with little sun. Once the battery is at about 5-10% state of charge, normal charging can resume. Do not charge with the on board charger from 0 state of charge, it will damage it. Unless you have a variable bench power supply, your best bet to bring it up slowly, is your solar. In the morning it will start with few watts and it will get better. Even now with solar until it gets dark can bring it up a little.
By the way, this is not a issue, it’s quite normal behaviour for LiFePo4 in this state, just not understood, because the bms should limit the charge rate vs state of charge. Some bms do not offer this and you have to manage yourself.

 

[camperblast]

Hello camperblast,
If the battery is very discharged, you have to bring it up very slowly, with a very low charge rate, much slower than your on board charger.
The best is with the solar charger with little sun. Once the battery is at about 5-10% state of charge, normal charging can resume. Do not charge with the on board charger from 0 state of charge, it will damage it. Unless you have a variable bench power supply, your best bet to bring it up slowly, is your solar. In the morning it will start with few watts and it will get better. Even now with solar until it gets dark can bring it up a little.

Thank you for this great answer. It is very much appreciated.
I will take the camper off the grid and turn the battery on tonight so that it catches the early morning sun.
Hope it will work

 

[cmcardle75]

Thank you for this great answer. It is very much appreciated.
I will take the camper off the grid and turn the battery on tonight so that it catches the early morning sun.
Hope it will work

You've got a reasonable chance, I'd think. Lithium are much easier to recover from deep discharge than lead acids, especially if the BMS was kind and turned off the power early enough. If there were lead acid, I'd take them straight down the tip.

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[Raul]

You've got a reasonable chance, I'd think. Lithium are much easier to recover from deep discharge than lead acids, especially if the BMS was kind and turned off the power early enough. If there were lead acid, I'd take them straight down the tip.

But, you can take Li to 0% SOC, not without degradation but it’s possible. All depends on how well the cells are balanced at the bottom. It’s not a recovery as such, more like a slow recharge. If the bms cut out on first cell reaching the limit, then is safe to charge back. If they take charge, and hold a charge well, happy days.

 

[Pausim]

What make is the battery? The manufacturer may well have some helpful advice about charging after full discharge. For example Relion suggest that if the BMS has done a full shut down on low voltage it may need jump starting, they suggest recharging it in parallel with another 12V battery to get it restarted. I think it is unlikely that you will have done much long term damage to the cells.

 

[poppycamper]

fully charged indefinitely

Bad idea... lithiums should not be left at 100% soc indefinitely....Will degrade battery quicker ... 70-80% ideal.!!!

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[cmcardle75]

Bad idea... lithiums should not be left at 100% soc indefinitely....Will degrade battery quicker ... 70-80% ideal.!!!

Yes, I didn't mean it would be a good idea, but it's probably better than allowing it to go to 0% for a few years!

Best is to get it to 70% and totally disconnect, BMS and all, if possible.