LiFePo4 batteries in winter

[Hoovie]

Well, I have made sure I have DISABLED any chargers disabling their charging functions when the temp gets down to zero Celcius so they keep working in the cold and my Lithiums Batteries get power into them!
How else can you warm up the Lithiums in freezing weather unless you have current going into them?


I would recommend other people with *certain* Lithium Batteries ensure that they may also not want to be disabling the chargers in very cold weather as well
Otherwise the built-in heaters on the better ones will never get any power to the heater

 

[gerry mcg]

I have the Votronic vcc1212-50 B2B with temperature sensor, plus Victron IP22 charger and victron MPPT connected with a VE.networked Victron Smartbatterysense connected to a ks-energy 205Ah underseat battery.
The SBS provides temperature and voltage info to the Victron charger and MPPT, with a low temperature cut off set at 5C.
I can manually sever the charger / B2B supply by an isolator should I wish, and I can turn off the MPPT charging via the victron app should I wisk.
Plus there is the onboard KS-ENERGY BMS that is acting as last line of defense.

I think that covers all eventualities

 

[peterc10]

I have a fairly similar system (lithium batteries and Victron IP22 main charger). If you have switched off the IP22, is that not your EHU charger? On mine, they removed the fitted charger as it had no lithium profile. So now the IP22 is my hook up charger. So does the EBL have another mains charger? Sorry if I have not understood what you’re doing.

Also anxious about leaving my van plugged into EHU, I switched off the IP22 in the settings section and used EHU to power any 230v gear whilst using the van. But now it’s in storage indoors (so no solar) I just let the lithiums sit and hope the battery master keeps the cab battery topped up. Every two weeks or so, I go and check and if necessary plug in the IP22 for a couple of hours. So far, from full, the lowest the lithium State of charge after two weeks is 78%.

The EBL has always charged the leisure batteries and also gave a separate trickle charge to the engine battery. I have now disabled the leisure battery charging by removing the fuse on the EBL for it, because the EBL has no lithium profile. The IP22 has taken over the role of charging the new leisure batteries when on EHU because it does have a lithium profile. However the EBL still trickle charges the engine battery, which is just a normal lead acid battery. So I have no need for a battery master.

We park our motorhome at home and can keep it plugged into the EHU all the time if we want. Assuming your lithiums are about the size of mine (2x120Ah) it looks like the average discharge from your motorhome's background electronics is only about 0.15A. That has given me food for thought. because I had not done the maths. That means 8 weeks and the lithiums would be getting critically low (approaching 10%). I think I need to work out what my average draw current is before deciding what way to go.

 

[Ingwe]

The EBL has always charged the leisure batteries and also gave a separate trickle charge to the engine battery. I have now disabled the leisure battery charging by removing the fuse on the EBL for it, because the EBL has no lithium profile. The IP22 has taken over the role of charging the new leisure batteries when on EHU because it does have a lithium profile. However the EBL still trickle charges the engine battery, which is just a normal lead acid battery. So I have no need for a battery master.

We park our motorhome at home and can keep it plugged into the EHU all the time if we want. Assuming your lithiums are about the size of mine (2x120Ah) it looks like the average discharge from your motorhome's background electronics is only about 0.15A. That has given me food for thought. because I had not done the maths. That means 8 weeks and the lithiums would be getting critically low (approaching 10%). I think I need to work out what my average draw current is before deciding what way to go.

Thank you, I understand now. I wasn’t aware that your EBL also sent a trickle charge to your vehicle battery. It doesn’t on our van (leisure only) as we learnt to our cost. Fitted a battery master and, touch wood, have had no issues since. Since fitting the BM, we have had two 110ah lithium batteries fitted under the passenger seat. As we can’t leave the van at home (street’s too small) it’s in indoor storage. I‘d prefer not to keep it plugged in all the time but hopefully, being indoors, it shouldn’t drop much below 6-7° over winter. I may have to reappraise things as we go. But going every two weeks or so, just to check things, isn’t much of a PIA.

 

[peterc10]

Thank you, I understand now. I wasn’t aware that your EBL also sent a trickle charge to your vehicle battery. It doesn’t on our van (leisure only) as we learnt to our cost. Fitted a battery master and, touch wood, have had no issues since. Since fitting the BM, we have had two 110ah lithium batteries fitted under the passenger seat. As we can’t leave the van at home (street’s too small) it’s in indoor storage. I‘d prefer not to keep it plugged in all the time but hopefully, being indoors, it should drop much below 6-7° over winter. I may have to reappraise things as we go. But going every two weeks or so, just to check things, isn’t much of a PIA.

The term EBL is short for Electrobloc which is the trade name for chargers and 12v distributing units manufactured by Schaudt in Germany. AFAIK all of these EBLs have the same dual charge function, but I doubt that your Bailey will have a Schaudt EBL. It's a bit like calling a Dyson a Hoover

^{_{Subscribers  do not see these advertisements}}

 

[Ingwe]

The term EBL is short for Electrobloc which is the trade name for chargers and 12v distributing units manufactured by Schaudt in Germany. AFAIK all of these EBLs have the same dual charge function, but I doubt that your Bailey will have a Schaudt EBL. It's a bit like calling a Dyson a Hoover

Our Bailey definitely did not have a Schaudt EBL. Lucky it came with a battery!

 

[bigtwin]

That has given me food for thought. because I had not done the maths. That means 8 weeks and the lithiums would be getting critically low (approaching 10%).

Your BMS should take care of that by isolating the discharge on low voltage cut-off, shouldn’t it?

One of the big advantages of LFP is that they have a BMS that will protect the battery in the event that certain parameters exceed predetermined levels. In that respect they are much easier to look after (much harder to damage) than SLA, however they appear to be causing you some consternation.

Ian

 

[peterc10]

Your BMS should take care of that by isolating the discharge on low voltage cut-off, shouldn’t it?

One of the big advantages of LFP is that they have a BMS that will protect the battery in the event that certain parameters exceed predetermined levels. In that respect they are much easier to look after (much harder to damage) than SLA, however they appear to be causing you some consternation.

Ian

Ian, my approach on all of this is one of belt and braces. As I have said before I do not want to just rely on the protection of the BMS. I am not sure about your harder to damage than FLA suggestion. Charging when the temperature is at or below zero centigrade and fully discharging will both cause terminal damage to Lithium batteries I have been told. The latter applies to the FLAs, but not the former.

 

[bigtwin]

Ian, my approach on all of this is one of belt and braces. As I have said before I do not want to just rely on the protection of the BMS.

I can see that but isn’t that a bit like insisting on disconnecting the EHU cable overnight because, in the event of a fault, you don’t want to risk the possibility of the RCD/MCB protection not operating when you’re asleep?

Charging when the temperature is at or below zero centigrade

But this isn’t possible as the BMS, an integral part of the battery, won’t permit it.

fully discharging will both cause terminal damage to Lithium batteries I have been told.

Again, this is not possible as the BMS prevents it. There is no such protection available for SLA batteries.

SLA batteries suffer damage if they remain in partial states of discharge, this is not the case with LFP and is the most common cause of damage to SLA batteries.

If you’re determined to ignore the features/benefits provided by the BMS, then you’d be best simply physically isolating the batteries whenever you’re not using the MH. However I’m not sure that’s how manufacturers envisaged their products (that provide significant benefits over SLA installations) being used.

Ian

 

[peterc10]

I can see that but isn’t that a bit like insisting on disconnecting the EHU cable overnight because, in the event of a fault, you don’t want to risk the possibility of the RCD/MCB protection not operating when you’re asleep?



But this isn’t possible as the BMS, an integral part of the battery, won’t permit it.



Again, this is not possible as the BMS prevents it. There is no such protection available for SLA batteries.

SLA batteries suffer damage if they remain in partial states of discharge, this is not the case with LFP and is the most common cause of damage to SLA batteries.

If you’re determined to ignore the features/benefits provided by the BMS, then you’d be best simply physically isolating the batteries whenever you’re not using the MH. However I’m not sure that’s how manufacturers envisaged their products (that provide significant benefits over SLA installations) being used.

Ian

It is about a making what I think is a sensible risk assessment. Nothing I am suggesting is going to cost me much, but the downside if things go wrong could cost me a lot.

I simply do not have the confidence you seem to have in the manufacturing and electronics of these batteries nearly all of which are from China. Surely life has taught you that new things sometimes go wrong. And Chinese electronics sometimes fry. I am simply not going to risk over £1k of my own hard earned money on a "trust me I have been making these batteries for a year" sales pitch. As I have said before I am not suggesting that anybody else has this belt and braces approach, but I am still going to apply it. I hope I had made that very clear in my previous posts.

^{_{Subscribers  do not see these advertisements}}

 

[Drexl]

I don't isolate my 2x100Ah Sterling lithium iron phosphate batteries during winter. Using a Votronic 60/40/430 triple - mains charger / B2B/ solar controller has been in use during several sub zero temps last winter (van in NE Scotland on the driveway). The Votronic has the temp probe on the battery terminal and the BMS has its own internal battery temp sensor - temp dropping below +3 Deg C prohibited charging. Once temp raised again charging resumed at about + 5 Deg C. I monitored that through the votronic app and the Sterling BMS app. So I do not have any worries about damaging the batteries due to charging below 0 Deg C. Two separate control systems are there to prohibit it.

 

[peterc10]

I don't isolate my 2x100Ah Sterling lithium iron phosphate batteries during winter. Using a Votronic 60/40/430 triple - mains charger / B2B/ solar controller has been in use during several sub zero temps last winter (van in NE Scotland on the driveway). The Votronic has the temp probe on the battery terminal and the BMS has its own internal battery temp sensor - temp dropping below +3 Deg C prohibited charging. Once temp raised again charging resumed at about + 5 Deg C. I monitored that through the votronic app and the Sterling BMS app. So I do not have any worries about damaging the batteries due to charging below 0 Deg C. Two separate control systems are there to prohibit it.

Do Votronic have an app and how does it link to the phone? I know Victron has an app linked via Bluetooth, but I can't see any way to link my votronic wired B2B and solar controller.

 

[Raul]

Do Votronic have an app and how does it link to the phone? I know Victron has an app linked via Bluetooth, but I can't see any way to link my votronic wired B2B and solar controller.

It doesn’t as far as I know. But, it does have a display panel, quite comprehensive, it’s linked to the votronic trio unit, and you can see most things. Settings are done via dip switches, old school but robust.

 

[peterc10]

It doesn’t as far as I know. But, it does have a display panel, quite comprehensive, it’s linked to the votronic trio unit, and you can see most things. Settings are done via dip switches, old school but robust.

Yes that is what I thought and why I queried Drexl. But I have found there is an Android Votronic app but it can't connect to any of my old school Votronic chargers. Ironically it picks up my Victron gear and it says it is connected to them but I can't get any information on them. So now I am very confused!

 

[tonyidle]

Can someone explain a "lithium charge profile"? I've built a 210Ah battery using four CALP cells. I have the manufacturers data sheet. It states current limits during charge at a fixed voltage. And that's it. No charging staged - nothing.

Because I will at times use the van on EHU with the battery fully charged I need to choose a "float" voltage. This should probably be 13.4v or thereabouts but as long as its below the 80% storage voltage it'll be fine.

The only disadvantage in making do with a decent charger designed for lead acid (or variants) is that the lithium will never achieve full charge. No harm to the lithium will result and full charge will be achieved from solar or battery to battery sources.

^{_{Subscribers  do not see these advertisements}}

 

[gerry mcg]

The lithium charge profile on a Victron IP22 (14.2v bulk / 13.5v float) is similar to the Gel setting on a EBL (14.4v bulk with 13.7v float), but the EBL Gel has a 16h float voltage, whereas you don’t require an extended 16h float at 13.7v for lithium, so it sits at 13.5v.

Operation

www.victronenergy.com

 

[Drexl]

Do Votronic have an app and how does it link to the phone? I know Victron has an app linked via Bluetooth, but I can't see any way to link my votronic wired B2B and solar controller.

You need to get the bluetooth module and download the Votronic app.
The app only displays data - it can't configure settings.

Votronic 1430 Bluetooth Connector S-BC

<p><span style="font-size:14px;"><span style="font-family:arial,helvetica,sans-serif;">This Bluetooth adaptor, enables you to see how your vehicle&...

www.roadpro.co.uk

 

[peterc10]

You need to get the bluetooth module and download the Votronic app.
The app only displays data - it can't configure settings.

Votronic 1430 Bluetooth Connector S-BC

<p><span style="font-size:14px;"><span style="font-family:arial,helvetica,sans-serif;">This Bluetooth adaptor, enables you to see how your vehicle&...

www.roadpro.co.uk

At that price I think I won't bother. The Victron bluetooth dongle for my BMV 700 cost me about £100 less! As I said in my subsequent post I did find the Votronic app. Ironically it recognises my Victron gear and tries to connect to it.

I have a Votronic B2B and MPP solar regulator both of which are set to their standard lithium profiles (which can't be changed) and both have temperature sensors. I have a Victron BMV battery monitor with the bluetooth dongle, bluetooth temperature sensor and IP 22 mains charger. The Victron app gives me plenty of information and will also allow me to modify the charging parameters on the IP22's lithium profile, once I have set it up properly. In addition I have the KS bluetooth battery monitor app that tells me what is happening with the batteries, but will not allow me re-configure the batteries' BMS

But all of these only tell me what has happened or is happening, not what will happen. That is why I want to put in some belt and braces provisions to try to make sure that if something should go wrong it will not cause damage.

 

[the1andonly]

Peter
I agree with your approach of not relying on the battery bms. I have votronic duo mppt and b2b chargers connected directly to the battery not via ebl or cbe (in my case). First winter I fitted an isolator on battery negative (lipo4) and left solar do it business for starter battery. I have also fitted the votronic temperature sensors for each controller (votronic now prevent the low temperature charging) . I now have a more sophisticated control via ssr and bmv712 set on soc to the switch the relay.

 

[AdrianChen]

Well all the above made me wonder what my system will do if the temps drop enough to get my Eccotree batts down to low enough temperatures that the low levels of winter solar charging might cause some damage (theres no EHU at the storage park). I have Victron gear so was able to set the Low temp cutoff points in the 100/50 Solar and Multiplus II to 5c but the Orion B2B has no such facility so I will have to remember to disable that or perhaps use a temp switch to do it automatically which would be easy. All the Victron boxes are very close to the batteries which are in the garage and sitting on a false floor in the void between the double floors they should be very similar in temp to the batteries themselves. Peterc's belt and braces approach is infectious! I might install some additional temp sensors so the charge sources can adjust the profiles to temperature rather than just relying on the BMS.
Thanks to all for posting and kick starting the grey cells.....

^{_{Subscribers  do not see these advertisements}}

 

[Lenny HB]

So now the IP22 is my hook up charger. So does the EBL have another mains charger? Sorry if I have not understood what you’re doing.

The EBL has two charger outputs the main 18 amp onechsrges the leisure battery and a trickle charge output for the starter battery.
Peter has removed the fuse that feeds the leisure battery charger so the EBL will just charge the starter battery.

 

[Jimbohorlicks]

My Ecotree 100ah lithium ,is Bluetooth and also has a heater built in.I have been monitoring mine over the last week or so as it's on the drive with solar connected but not in direct sunlight as the drive is down a little at the wrong angle, the battery was at 80% soc and dropped down to 73% with the van control panel switched on( over a week) with it off its heading back to 80% .
we had some frost yesterday but didn't notice that the battery wasn't charging,but will certainly recheck in the colder weather. There is a temperature monitor on the app but it just shows the temperature, no cut off points.

 

[Hoovie]

My Ecotree 100ah lithium ,is Bluetooth and also has a heater built in.I have been monitoring mine over the last week or so as it's on the drive with solar connected but not in direct sunlight as the drive is down a little at the wrong angle, the battery was at 80% soc and dropped down to 73% with the van control panel switched on( over a week) with it off its heading back to 80% .
we had some frost yesterday but didn't notice that the battery wasn't charging,but will certainly recheck in the colder weather. There is a temperature monitor on the app but it just shows the temperature, no cut off points.

If it has a heater, there probably isn't a cut off point as the BMS should just automatically divert the current to the heater pad.
If the battery isn't charging when cold (in that there is no current going into it) then maybe you have a temp cut-off on the charger, which you need to disable, otherwise having a heater is a bit pointless.

 

[Jimbohorlicks]

I don't believe I have a temp cut off on the solar controller, but I will check it next time its cold, currently my battery was showing as 9 degrees..

 

[peterc10]

I don't believe I have a temp cut off on the solar controller, but I will check it next time its cold, currently my battery was showing as 9 degrees..

You shouldn't need it Jim as long as your heatpad works. What solar controller do you have?

^{_{Subscribers  do not see these advertisements}}

 

[Jimbohorlicks]

You shouldn't need it Jim as long as your heatpad works. What solar controller do you have?

I have an mppt controller but its not lithium configured, so it's set on a gel setting. I realise this is not ideal and shall be looking to replace it with a lithium compatible mppt controller. I don't get the full solar amps with the gel setting but it will suffice for now. The problem being is that as the lithium battery is always at 13 + amps the controller sees this as a fully charged gel battery and compensates accordingly and only trickle charges.

 

[AdrianChen]

You shouldn't need it Jim as long as your heatpad works. What solar controller do you have?

Yes agree if there is a heatpad its not necessary - mine do not have one, and I will forget!!!! Doubt there would be much of an issue with the low charging current Im seeing from the winter sun - but

 

[Hoovie]

Yes agree if there is a heatpad its not necessary - mine do not have one, and I will forget!!!! Doubt there would be much of an issue with the low charging current Im seeing from the winter sun - but

Most lithium batteries without heaters are actually happy with a low current charge even when below 0C (typical value quoted is 1/10C, so under 10A for a 100Ah Battery) so solar in Winter is likely to be fine, but chances are the BMS would stop the battery accepting charge regardless at that temp and if it didn't, it is possible on the odd bright winters day you could get more, so a risk maybe not worth taking.

 

[AdrianChen]

Most lithium batteries without heaters are actually happy with a low current charge even when below 0C (typical value quoted is 1/10C, so under 10A for a 100Ah Battery) so solar in Winter is likely to be fine, but chances are the BMS would stop the battery accepting charge regardless at that temp and if it didn't, it is possible on the odd bright winters day you could get more, so a risk maybe not worth taking.

Good to hear! We have 2*216AH batts so with 432AH I doubt it would be an issue in this country even with the 350 watts of solar we will have when I get round to swapping out the existing 100watt panels.

 

[Adriaadventure]

Is it not possible to isolate the charge input via the LFP’s BMS? That would be the simplest method.

In terms of SoC for storage, around 50% should be fine.

Ian

I realise this a 4-month old post I am replying to, but I am fairly sure that the instructions for the Votronic solar MPPT units state that the Habitation battery must always be connected as the regulator cannot regulate the voltage charging correctly without the hab battery being connected ?

^{_{Subscribers  do not see these advertisements}}