Lithium hab battery in sub zero weather

[Dolmen]

I rely on my Lithium hab battery to maintain my cab battery via a votronic battery maintainer (battery master) as I have no solar. The system is working perfectly and at the rate of drain I have seen to date it would be many months before the lithium battery was depleted, however, with the current sub zero temperatures I am wondering what effect it will have on the lithium if any ie will the lithium battery lose some charge just because of the cold weather or can it only lose what is being drained from it by the cab battery, I am not expecting any problems, just not sure how all this works so apologies if its a stupid question.

 

[Ingwe]

Looking forward to the answers.

 

[Verteuil Man]

There is a report that Tesla caras are being abandoned in the US because of the very low temperatures. Could be a similar process.

 

[bigtree]

I was at my van yesterday,the temperature was -1 and the cab battery was being charged via an AMT12-2 from the Fogstar,albeit not doing a great job so have changed the settings on the AMT.

 

[Spriddler]

Another discussion re lithium/low temps was started this morning which has some informative comments.......

Broken Link Removed

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[Guigsy]

There is a report that Tesla caras are being abandoned in the US because of the very low temperatures. Could be a similar process.

Many cars, including Teslas until recently, use lithium nickel manganese batteries. Motorhome hab batteries are lithium Iron Phosphate. These can discharge in sub zero temperatures. Just they can't charge.

And anyway. When will you use your motorhome when it's below freezing INSIDE?

And if you've got a FogStar, it's got built in heating pads to warm it.

 

[funflair]

I rely on my Lithium hab battery to maintain my cab battery via a votronic battery maintainer (battery master) as I have no solar. The system is working perfectly and at the rate of drain I have seen to date it would be many months before the lithium battery was depleted, however, with the current sub zero temperatures I am wondering what effect it will have on the lithium if any ie will the lithium battery lose some charge just because of the cold weather or can it only lose what is being drained from it by the cab battery, I am not expecting any problems, just not sure how all this works so apologies if its a stupid question.

I don't think you will have any problem as the Votronic will only be taking a trickle to the starter battery, the battery will possibly have a minimum temperature for discharge as controlled by the BMS but that would be quite low and should not be an issue, out of interest is your Battery maintainer Lithium specific or just the standard one (not even sure Votronic do a Lithium one).

 

[Ian_H]

I was at my van yesterday,the temperature was -1 and the cab battery was being charged via an AMT12-2 from the Fogstar,albeit not doing a great job so have changed the settings on the AMT.

Have you ever activated the battery heater by charging below zero C? I'd like to know what I should see on the app in this situation. I understand the charge should be diverted to the heater until the battery is warm enough, but don't know whether the app would show any current as its not going into the cells at that point. Also don't know whether app shows any alarms or other indications. Asked Fogstar on their Facebook group but not got an answer so far.

 

[Dolmen]

I don't think you will have any problem as the Votronic will only be taking a trickle to the starter battery, the battery will possibly have a minimum temperature for discharge as controlled by the BMS but that would be quite low and should not be an issue, out of interest is your Battery maintainer Lithium specific or just the standard one (not even sure Votronic do a Lithium one).

Just the standard one, works really well and different to what I have read on various sites eg Roadpro say it only works when receiving a charge eg solar, however the voltronic simply sees the lithium battery as higher than the cab battery and keeps it about 0.5v below. Voltronics own web site says not suitable for lithium technologies, however, Victron engineers take that to mean lithium to lithium and say it’s good for lithium to normal battery, all I know is that it works perfectly and is trouble free. Discharge, pre heating etc all controlled by the battery bms which I never fiddle with, wanted a fit and forget solution

 

[Dolmen]

Have you ever activated the battery heater by charging below zero C? I'd like to know what I should see on the app in this situation. I understand the charge should be diverted to the heater until the battery is warm enough, but don't know whether the app would show any current as its not going into the cells at that point. Also don't know whether app shows any alarms or other indications. Asked Fogstar on their Facebook group but not got an answer so far.

I have not charged it during this cold spell, however, if needed the bms would activate the pre heater first as you say. I’m not 100% sure, however, I believe pre heater would only draw power from ehu and not from the battery itself(?). Like yours, my cab battery has continued to be fed by the leisure battery, I don’t think cold weather discharge kicks in until -10 or 20, will need to check app. I do not have an app for the voltronic so only know it’s working by looking at the cab battery app which shows it is rock steady. The lithium battery app I never fiddle with

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[bigtree]

Have you ever activated the battery heater by charging below zero C? I'd like to know what I should see on the app in this situation. I understand the charge should be diverted to the heater until the battery is warm enough, but don't know whether the app would show any current as its not going into the cells at that point. Also don't know whether app shows any alarms or other indications. Asked Fogstar on their Facebook group but not got an answer so far.

I think the heater comes on itself when it reaches a certain temperature.

 

[jwells]

I spent too much time with trying to see what happens with my battery today started this morning at -3°c! I wanted to know at least it is working as it should, all I have achieved is wanting to know more! Must be something to do with having worked in a test /development lab and not trusting anything will be as intended! Biggest problem is not having a test lab, only a very cold van!
When the solar charger started to output and the bms was below freezing, the bms appeared to be switching the battery charging off/on, and was actually allowing pulses of current into the battery! At the same time it was flashing the Utc warning! After a very long time the battery cells did rise above - 0.0°c but I now have 331 counts of UTC in the history! Not how I would expect it to operate, so I need to get more information to understand what I saw!

 

[Ian_H]

I spent too much time with trying to see what happens with my battery today started this morning at -3°c! I wanted to know at least it is working as it should, all I have achieved is wanting to know more! Must be something to do with having worked in a test /development lab and not trusting anything will be as intended! Biggest problem is not having a test lab, only a very cold van!
When the solar charger started to output and the bms was below freezing, the bms appeared to be switching the battery charging off/on, and was actually allowing pulses of current into the battery! At the same time it was flashing the Utc warning! After a very long time the battery cells did rise above - 0.0°c but I now have 331 counts of UTC in the history! Not how I would expect it to operate, so I need to get more information to understand what I saw!

What make is your battery? I have had the same idea and stuck my yet to be fitted fogstar outside this afternoon! I will have a play when it gets below zero this evening....

 

[Tombola]

No they can supply current at a lower temps than they can recieve charge. Some down to minus 20, (check the factsheet)

just check the leisure battery SOC now and then

 

[starquake]

Many cars, including Teslas until recently, use lithium nickel manganese batteries. Motorhome hab batteries are lithium Iron Phosphate. These can discharge in sub zero temperatures. Just they can't charge.

And anyway. When will you use your motorhome when it's below freezing INSIDE?

And if you've got a FogStar, it's got built in heating pads to warm it.

I'd note the Korean EV's (at least) and many Tesla models also have a heating system as well as cooling for battery. Mine kicks in when its -10 celcius outside.

There was a guy doing Videos of him driving his Kia EV in Finland at -40 celcius in Finland in the North ... the comment he was making was it was better than his Petrol and Diesel vehicles where he needed heaters in the tanks (as well as engine block heating) to stop the actual fuel freezing in those artic conditions.

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[Guigsy]

I'd note the Korean EV's (at least) and many Tesla models also have a heating system as well as cooling for battery. Mine kicks in when its -10 celcius outside.

There was a guy doing Videos of him driving his Kia EV in Finland at -40 celcius in Finland in the North ... the comment he was making was it was better than his Petrol and Diesel vehicles where he needed heaters in the tanks (as well as engine block heating) to stop the actual fuel freezing in those artic conditions.

Yeah. I wondered about that too. Many BEVs have active heating and cooling on their batteries. Including Teslas. A few don't (Leaf?). So is this story really true?

 

[jwells]

Can we keep this thread to habitation batteries please!
No problem with battery discharge below freezing, it's what actually happens to the charging bms control below freezing!

 

[starquake]

Yeah. I wondered about that too. Many BEVs have active heating and cooling on their batteries. Including Teslas. A few don't (Leaf?). So is this story really true?

Well the leaf definitely has no active thermal management, but even the Stellantis group EV's do these days. It's gotta be FUD against EV's given the actual people using them in places where it's really cold like Finland in prefernce to ICE vehicles.

 

[starquake]

Can we keep this thread to habitation batteries please!
No problem with battery discharge below freezing, it's what actually happens to the charging bms control below freezing!

And totally agree on this, you can use, but not charge a Lithium in below 0.

I do wonder how many people configure their solar charge controllers correctly for this thermal compensation.

 

[Ian_H]

I was at my van yesterday,the temperature was -1 and the cab battery was being charged via an AMT12-2 from the Fogstar,albeit not doing a great job so have changed the settings on the AMT.

What settings did you change from and to?

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[bigtree]

What settings did you change from and to?

I had it on setting 6 , I have now attached a flying lead from the leisure battery terminal to switch 2 terminal. This makes it charge longer.

 

[Bessy765]

We have Transporter Lithium batteries which can be used to supply current down to -20c and charged from -4c
they have a ten year warranty.

Not cheap but you pays your money

 

[DavidG58]

Interesting question, our leisure batteries are housed in an external locker with no heating or insulation I would predict temperature inside will be very close to ambient outside

I am happy with my gel for now but had thought I would upgrade to lithium when change needed, but I will rethink now

 

[Gromett]

I rely on my Lithium hab battery to maintain my cab battery via a votronic battery maintainer (battery master) as I have no solar. The system is working perfectly and at the rate of drain I have seen to date it would be many months before the lithium battery was depleted, however, with the current sub zero temperatures I am wondering what effect it will have on the lithium if any ie will the lithium battery lose some charge just because of the cold weather or can it only lose what is being drained from it by the cab battery, I am not expecting any problems, just not sure how all this works so apologies if its a stupid question.

You will have no problems at those temps discharging a Lithium battery. It is only when you....

There is a report that Tesla caras are being abandoned in the US because of the very low temperatures. Could be a similar process.

They are trying to charge them. The reports are totally unclear what is happening. But not even remotely related to the OP.... Sorry

 

[Raul]

I spent too much time with trying to see what happens with my battery today started this morning at -3°c! I wanted to know at least it is working as it should, all I have achieved is wanting to know more! Must be something to do with having worked in a test /development lab and not trusting anything will be as intended! Biggest problem is not having a test lab, only a very cold van!
When the solar charger started to output and the bms was below freezing, the bms appeared to be switching the battery charging off/on, and was actually allowing pulses of current into the battery! At the same time it was flashing the Utc warning! After a very long time the battery cells did rise above - 0.0°c but I now have 331 counts of UTC in the history! Not how I would expect it to operate, so I need to get more information to understand what I saw!

The way the heater work is using the charge current to heat up. Depending on the heater pad, some want a 4A to start heating, any less will just not start heating, and bms will trigger the low temp protection. You can test this with a bench power supply, and give it a 3a then a 4a and see when it start heating. Some heaters are small some are as hungry as 4a. And if this feed it is not met, the heater will not do its job, resulting in a low voltage trigger protection.

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[Ian_H]

Some results: My Fogstar 230Ah underseat battery.
Below the UTC temp I put on a charge with my Victron set at 15A. It generated a UTC alert on the app screen and showed no current charging to the cells. The clamp meter showed 4A going in, presumably to the heater. The temp rise was slow, less than 1 degree in 10 minutes, but with an input of only 14x4 = 56W it isn't going to happen quickly with such a big lump of battery. Obviously heat up rate will depend on battery size, insulation and environment temperature.
When the UTC alert disappeared the charge current immediately started to flow automatically with no action required from me.
Fogstar tell me the new version of the app will show when the heater is active.
Edit: Between zero and 5C the charger was putting in 15A but the battery received about 11A, so the heater stayed on. Above 5C the heater turned off and the full 15A was shown on the app going into the cells.

 

[jwells]

Thank you Raul and Ian_H for your information, confirmed my feelings about leaving the charge selected off in the app until I have the available input charging supply!

 

[Ian_H]

Thank you Raul and Ian_H for your information, confirmed my feelings about leaving the charge selected off in the app until I have the available input charging supply!

Simply having charge selected didn't cause an alarm. It only raised the UTC alarm when I turned the charger on to apply current. It might get messy if weak solar charging comes on below/around the 4A (in my case) mark, as Raul mentioned.

 

[Ian_H]

All the way back to OP original question whether the battery will lose charge in cold weather:
I turned charge and discharge off about 6 weeks ago and the soc was 45%. Yesterday when I turned it back on I did notice the SOC was 39%. Since the bms had not seen any current leaving the battery, I am guessing that it has reduced the SOC based on temperature? Anybody know whether the bms does this or not?

 

[Dolmen]

All the way back to OP original question whether the battery will lose charge in cold weather:
I turned charge and discharge off about 6 weeks ago and the soc was 45%. Yesterday when I turned it back on I did notice the SOC was 39%. Since the bms had not seen any current leaving the battery, I am guessing that it has reduced the SOC based on temperature? Anybody know whether the bms does this or not?

Interesting, think this was the core of my question, ie can temperature alone reduce the state of charge or can it only be reduced if something electrical is pulling it.