Lithium Batteries: Cold Weather Question

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Gizmo

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Bellingham,WA
I have recently completed the solar install on our new truck camper and it is performing very well, even with the minimal battery capability that came with our TC.  I will be installing the inverter soon.  After I am finished with all the installs and I am satisfied with the performance of everything, I will be replacing the original batteries with lithium.  In my research on these batteries, I have learned they should/must not be charged when temps drop to and below 32 degrees.  Our fulltime plans are not to be in cold weather very long if at all except maybe the first winter where my wife may take a job for a year and the occasional unexpected drop in temperature, after that we plan to follow the weather to avoid the extremes.  My only option to place the batteries is in the battery box because of space constraints and personal needs.  While we will be mostly boondocking, our plan when faced with cold weather is to stay in a CG/RV park with electric hook-up.  So, I would like to hear what suggestions you'all may have regarding heating the battery box to above the freezing point at least, considering we plan to have electrical hook-up available.  Ideas I have come up with so far is to place a work light with an incandescent bulb or perhaps a heat lamp in the box.  Another idea I am wondering about is locating a suitable heating pad of some sort.  I will be interested to hear ideas, suggestions and any product recommendations. Thanks.
 
You might get hold of ASTravelers. He's got some practical experience with LI batteries. When our AGM house batteries are no longer viable, I'd love to replace them with LI technology (if I can be convinced that their limitations can be overcome) but our AGMs are six years old and still going strong. We mostly boondock, and we rely heavily on solar power, so a lithium battery system would be ideal for our type of camping.

Unfortunately, to enable LI batteries to live anywhere near their theoretical lifespan, I'd need a completely different type of battery monitoring system - more accurately, a "battery management system." And to make them work with our auto gen-start sytem (which, in all honesty, we rarely use) we'd need some type of device that would make them work together. To my knowledge, no such system exists.

And it's not just the cold that limits LI technology, cumulative exposure to temps above 90 degrees F can severely lessen their AH storage capacity - in just a couple of years. I think you're on the right track seeking out some type of heating system for cold weather ops, but I'd probably be more concerned about warm weather ops - especially if the batteries would be exposed to outside temps. I'll be following your experiences closely.

Kev
 
Kevin Means said:
You might get hold of ASTravelers. He's got some practical experience with LI batteries. When our AGM house batteries are no longer viable, I'd love to replace them with LI technology (if I can be convinced that their limitations can be overcome) but our AGMs are six years old and still going strong. We mostly boondock, and we rely heavily on solar power, so a lithium battery system would be ideal for our type of camping.

Unfortunately, to enable LI batteries to live anywhere near their theoretical lifespan, I'd need a completely different type of battery monitoring system - more accurately, a "battery management system." And to make them work with our auto gen-start sytem (which, in all honesty, we rarely use) we'd need some type of device that would make them work together. To my knowledge, no such system exists.

And it's not just the cold that limits LI technology, cumulative exposure to temps above 90 degrees F can severely lessen their AH storage capacity - in just a couple of years. I think you're on the right track seeking out some type of heating system for cold weather ops, but I'd probably be more concerned about warm weather ops - especially if the batteries would be exposed to outside temps. I'll be following your experiences closely.

Kev

Kev I am new to LI and my learning will continue I am sure with experience.  What I have learned so far in talking with a couple mfg.s, you may not need a different battery monitoring system.  I am looking at a couple of the newer plug and play LI batteries which have internal battery monitoring management systems.  They have indicated to me any of the better higher quality battery monitors and charge controllers will work.  The consensus seems to be, the parameters for these LI batteries is essentially the same as AGM.  When the time comes to make the purchase and I decide on a particular battery, I will get the mfg's specs and set my monitor and controller accordingly.  I do have a generator, but no auto start device, so I cannot help you with that.  I plan to use the generator only as a plan B if conditions dictate, or to run the AC if needed.  I keep my converter off otherwise.  I was originally going to stick with AGM but besides some of the other real advantages to LI the compelling reason for me is weight which I have to keep tabs on because of the size of my TC.  I can install 3-100Ah LI with 10-20 pounds less weight than two 100 Ah AGM's. I'll be sure to update as I gain experience and use.
 
Kevin Means said:
And it's not just the cold that limits LI technology, cumulative exposure to temps above 90 degrees F can severely lessen their AH storage capacity - in just a couple of years. I think you're on the right track seeking out some type of heating system for cold weather ops, but I'd probably be more concerned about warm weather ops - especially if the batteries would be exposed to outside temps. I'll be following your experiences closely.

Kev

Kevan, 
Here something weird about LI batteries.  I was playing around on the Tesla site, in the specs about battery range it had several variable perimeters. One of them was the ambient temp.  As the temp went down, the range went down, but as the temp wet up  over 110 it got the best range.
 
Well Tesla is certainly on the cutting edge of LI technology, and there are different chemical makeups of lithium batteries, so maybe the high-temp issues have been resolved (That would be nice!) Our solar output and battery capacity are well-balanced (970 watts/840 AH) but an 840 AH LI battery setup would cost nearly $11,000.00. And from what I've read lately, our existing Magnum charger should work with modern LI batteries.

I could probably get similar performance out of an LI battery bank with about 25% less capacity (630 AH) because LI batteries can be drawn down farther, and more often, without damaging them, and they'll charge faster... but that's still an $8100.00 battery bank. There are still a lot of "should work" and "probablies" when making the switch to LI batteries. At current LI prices, I'm just going to need to get more confident in them before taking the plunge.

Kev
 
Hello folks,

Regarding LiFePO4 batteries, there's a recent trend on "plug-compatible" batteries which have a built-in BMS to make the battery basically indistinguishable from a normal Lead-Acid 12V battery. I learned about that recently from this blog post here:

http://www.theboondork.com/mainphp/im-glad-thats-over

Here are two examples:
https://battlebornbatteries.com/shop/12v-lifepo4-deep-cycle-battery/
http://www.lifebluebattery.com/lifeblue-battery-home-page/lifeblue-battery-features.html

The blogger I pointed to above has just installed four of these Battleborn batteries (1st link above) in his 5thWheel, replacing a previous lead-acid battery bank without changing a thing (besides moving the battery bank to under his bed, in an effort to provide better climate control for them), and it seems they are doing OK so far. As it's been just about a month since he installed them (see further posts on his blog) there's not nearly enough time yet to judge on long-range durability and performance, of course, but as the reputable folks at the N.Arizona Wind & Sun are selling these batteries too, I can't believe they are complete flops: https://www.solar-electric.com/battle-born-bb10012-100ah-12v-lithium-battery.html

Kevin, as LiFePO4s can safely be discharged down to 20% of their capacity without any ill effects, if these Battleborns really perform as expected, you'd need only 840*50%/80%=5.25 -> 6  of these batteries to replace your current bank... the cost would as of now be well under $6k, not $11k or $8.1k as you are figuring (that is, if all advertised data is true). And the weight economy, longer lifecycle, and much faster recharge times come as added bonuses.

We are really looking forward for more, longer term data on these batteries... we really want to be able to have them (or something similar) right from the start and skip lead-acids completely on our  future 5thWheel.

Cheers,
--
  Vall & Mo.
 
VallAndMo said:
Hello folks,

Regarding LiFePO4 batteries, there's a recent trend on "plug-compatible" batteries which have a built-in BMS to make the battery basically indistinguishable from a normal Lead-Acid 12V battery. I learned about that recently from this blog post here:

http://www.theboondork.com/mainphp/im-glad-thats-over

Here are two examples:
https://battlebornbatteries.com/shop/12v-lifepo4-deep-cycle-battery/
http://www.lifebluebattery.com/lifeblue-battery-home-page/lifeblue-battery-features.html


Kevin, as LiFePO4s can safely be discharged down to 20% of their capacity without any ill effects.

Actually I am consistently reading among the blogs and the Mfg.'s that LI batteries can safely be discharged down to 10% without any harm, but not a bad idea to take action in the 15-20% range to recharge.  Another benefit often overlooked is LI batteries charge faster.

Here are a couple more links:
https://greenlifebattery.com/
http://www.relionbattery.com/
https://www.lithiumion-batteries.com/

Of all of them, Battle Borne are the least expensive and getting some early positive reviews.





 
Hello Gizmo,

Gizmo said:
Actually I am consistently reading among the blogs and the Mfg.'s that LI batteries can safely be discharged down to 10% without any harm, but not a bad idea to take action in the 15-20% range to recharge.  Another benefit often overlooked is LI batteries charge faster.

Interesting. What I've been hearing is that, for maximum longevity, LiFePO4s should be charged until 95% (ie, do not charge the final 5%) and discharged until 15%, so that's how (5+15) I got my 20% number. By 10%, do you mean charging all the way to 100%, then discharging all the way to 10%? Or something else?

Here are a couple more links:
https://greenlifebattery.com/
http://www.relionbattery.com/
https://www.lithiumion-batteries.com/

Thanks for the links! Will be keeping an eye on them.

Cheers,
--
  Vall.
 
Yes you have it correct, charge to 100% and they can be discharged to as low as 10%, I would suspect it is will probably be prudent practice to not go that low on a regular basis, but this is all still new technology, so it will be interesting to see what our experience will be, as well as others who are going this route.
 
Hi Posters

I too am planning on installing LIP batteries from the git-go on a soon to be purchased TT.  I don't necessarily trust manufacturer's info on this topic.  I have tended to read, well actually study because it's complex stuff, on information contained at this web site -- which is all about ALL KINDS OF BATTERIES. 

http://www.mpoweruk.com/

Especially this section on Lithium Cell Failures.

http://www.mpoweruk.com/lithium_failures.htm

According to info at the above, you get best battery life (cycles) by charging to 90% or below 20%.  Nothing says you can't go above/below those numbers, but the ideal State of Charge working range is between 20% and 90%.

I realize there are different lithium ion chemistries, and one must be sure and stick with LIP for data and evaluation.  Some of the info in the last link may be generalized and out of date?, maybe more specific information about LIP best performance operating parameters has become available and I need to check out some the links others have posted.

I have been in contact off and on with AM Solar in Oregon, and even 6-8 mos. ago, they were expressing concern about whether LIP batteries would even be available for them to obtain.  The reason??  a world-wide shortage of lithium, ie. not enough mining capacity to meet the incredibly rising demand.  In looking at their prices now, compared to 6 mos. ago, the battery packs are quite more expensive.  Therefore, it appears that the price of lithium iron phosphate batteries (and likely other lithium ion bats) is high, not because of technology constraints or lack of markets, but rather because of the raw material shortage.  I don't think the prices are going to come down any time soon if that is the case. There are many reasons why mining capacity may not be able to ramp up quickly in some of the largest producing countries even though the market demand is high (politics, bribery, lack of equipment, no new deposits, etc.)

https://investingnews.com/daily/resource-investing/energy-investing/lithium-investing/lithium-producing-countries/

A little about which countries produce the most lithium.

Keep the info coming.

 
Hi Gizmo,

Gizmo said:
Yes you have it correct, charge to 100% and they can be discharged to as low as 10%,

Thanks for the clarification. So, as to that "bottom limit" (ie how deep to discharge), our numbers are quite close.

I would suspect it is will probably be prudent practice to not go that low on a regular basis, (...)

I suspect that going all the way to 100% is not very prudent either. I've read that LiFePO4s can be seriously damaged by overcharging (ie charging past 100%) even by just a little bit, and in the process of charging them to exactly 100%, I think it would be very easy to inadvertently go 1-2% over (due to imprecision in the measurements caused by temperature variations, component tolerances etc) and then end up damaging them.

Cheers,
--
  Vall.
 
A couple of things, the LI batteries that AM Solar sells are of the type requiring an external BMS and is a fairly complex set-up.  This kind of system in addition to being more complex, is also quite a bit more expensive to purchase than the plug and play LI batteries. Not saying this is bad and AM Solar is an excellent company with very good products and great customer service.  In the article linked to above, it spoke about over charging but one should know, at least with the plug and play LI batteries they have internal BMS systems and part of their job is to shut it down if an overcharge state is reached to protect the batteries.  I would suspect the external BMS LI batteries such as AM Solar sells with all it's sophistication would likely do the same, although after seeing the price of those kinds of systems, I lost interest in li batteries and pursued it no longer until the fairly recent advent of the plug and play systems which come with a much lower price tag and the plug and play aspect was also compelling for me.

As an update after reading the above links and seeing there may be a very high demand, making delivery a potential delay, I went to the Battle Borne website and found not only are they in stock, but the price was reduced $80.00 a piece since I first visited their website months ago, along with free shipping.  I was going to wait until I completed my last install, the inverter, but the price drop and availability expedited my plan.  So I have ordered 3-100Ah 12V batteries.  So far I can say this, the customer service was excellent.  I placed the order just before going to lunch today and while at lunch, I received a call wanting to verify my order and the pertinent details, after doing so, the representative said they will be shipped today.  Considering the company is in Nevada and we are in Phoenix, we should have them soon I suspect.

So we are official guinea pigs and will keep you all up to date on how it goes.
 
Hi DreamSend,

Dreamsend said:
I too am planning on installing LIP batteries from the git-go on a soon to be purchased TT.  I don't necessarily trust manufacturer's info on this topic.

Neither do I. The fact is that most of them only warrant their product up to 5 years or less (Lifeblue warranty is 10y long, but after 5y it becomes full of limitations), and a well-cared-for LiFePO4 reportedly lasts ~5000 cycles (which, even if you cycle them every single day, would be almost 14 years).

My rationale is that they don't have nearly as much incentive as the customer to make sure it lasts (not only because they would sure be happier if they sold you a new battery as soon after 5y as possible, but also because more complicated rules are surely harder to implement on a BMS and/or could end up scaring sales away if dumped on the customer).

I have tended to read, well actually study because it's complex stuff, on information contained at this web site -- which is all about ALL KINDS OF BATTERIES. 

http://www.mpoweruk.com/

Especially this section on Lithium Cell Failures.

http://www.mpoweruk.com/lithium_failures.htm

Thanks for the links. I think I've read that site over a few years ago, but the fact that I'm not sure is more than reason enough to read it again :)

According to info at the above, you get best battery life (cycles) by charging to 90% or below 20%.  Nothing says you can't go above/below those numbers, but the ideal State of Charge working range is between 20% and 90%.

Very close to the numbers I've seen (15% to 95%).

I realize there are different lithium ion chemistries, and one must be sure and stick with LIP for data and evaluation.  Some of the info in the last link may be generalized and out of date?, maybe more specific information about LIP best performance operating parameters has become available and I need to check out some the links others have posted.

Very good point. You're correct, the different Lithium-based chemistries actually behave quite differently, and we must be sure we're comparing apples to apples. And some manufacturers are very imprecise about exactly which chemistry they are using (Tesla is a case in point).

I have been in contact off and on with AM Solar in Oregon, and even 6-8 mos. ago, they were expressing concern about whether LIP batteries would even be available for them to obtain.  The reason??  a world-wide shortage of lithium, ie. not enough mining capacity to meet the incredibly rising demand.  In looking at their prices now, compared to 6 mos. ago, the battery packs are quite more expensive.  Therefore, it appears that the price of lithium iron phosphate batteries (and likely other lithium ion bats) is high, not because of technology constraints or lack of markets, but rather because of the raw material shortage.  I don't think the prices are going to come down any time soon if that is the case. There are many reasons why mining capacity may not be able to ramp up quickly in some of the largest producing countries even though the market demand is high (politics, bribery, lack of equipment, no new deposits, etc.)

https://investingnews.com/daily/resource-investing/energy-investing/lithium-investing/lithium-producing-countries/

A little about which countries produce the most lithium.

Keep the info coming.

I wasn't aware of that shortage. Oh my... :-\ But thanks for the info and the link.

Cheers,
--
  Vall.
 
Hi Gizmo,

Gizmo said:
So we are official guinea pigs and will keep you all up to date on how it goes.

Great news, and congratulations on your purchase, I think you made the right call. The guinea pig aspect should be more than compensated by the good deal you got, specially considering the Lithium shortage Dreamsend just warned us about.

I would do the same you did and order a set right now, but the sad fact is that currently I'm not even in the US... :-\

Looking forward to your reports!

Cheers,
--
  Vall.
 
Hi Gizmo

Congrats on getting your new solar all put together.  I'm sure you will enjoy it and all the benefits your efforts will reap.  Given the price drop you discovered, it makes me question if info I was given may be out of date, or even misleading.  AM Solar is definitely in upper cost level for their systems, but my initial researching showed them to be the best recommended.  I may try talking with an installer in Arizona (I'm not tied to Oregon by any means) and do some cost comparisons.  I think I was looking at $11,000 (cough, cough!) for size I want, but nearly half of that was labor for installing the entire system--panels, inverter/charging system, batteries, etc.

Anyway, hope it all goes together for you well.

Linda
 
VallAndMo said:
Hi Gizmo,

Great news, and congratulations on your purchase, I think you made the right call. The guinea pig aspect should be more than compensated by the good deal you got, specially considering the Lithium shortage Dreamsend just warned us about.

I would do the same you did and order a set right now, but the sad fact is that currently I'm not even in the US... :-\

Looking forward to your reports!

Cheers,
--
  Vall.

Dreamsend said:
Hi Gizmo

Congrats on getting your new solar all put together.  I'm sure you will enjoy it and all the benefits your efforts will reap.  Given the price drop you discovered, it makes me question if info I was given may be out of date, or even misleading.  AM Solar is definitely in upper cost level for their systems, but my initial researching showed them to be the best recommended.  I may try talking with an installer in Arizona (I'm not tied to Oregon by any means) and do some cost comparisons.  I think I was looking at $11,000 (cough, cough!) for size I want, but nearly half of that was labor for installing the entire system--panels, inverter/charging system, batteries, etc.

Anyway, hope it all goes together for you well.

Linda

Thank you both. Linda good luck to you as well, if you are referring to Northern Arizona Wind & Sun as an installer they are highly regarded as well for their installations.  I only have had experience with the sales and customer service side, which has been very good, but I have spoken with a couple of folks who have work done by them and they get raving reviews.  If you are talking about some of the Quartzite installers, I would look carefully as I keep hearing nothing but over priced and shoddy work out of Quartzite.   
 
Gizmo said:
I have recently completed the solar install on our new truck camper and it is performing very well, even with the minimal battery capability that came with our TC.  I will be installing the inverter soon.  After I am finished with all the installs and I am satisfied with the performance of everything, I will be replacing the original batteries with lithium.  In my research on these batteries, I have learned they should/must not be charged when temps drop to and below 32 degrees. Our fulltime plans are not to be in cold weather very long if at all except maybe the first winter where my wife may take a job for a year and the occasional unexpected drop in temperature, after that we plan to follow the weather to avoid the extremes.  My only option to place the batteries is in the battery box because of space constraints and personal needs.  While we will be mostly boondocking, our plan when faced with cold weather is to stay in a CG/RV park with electric hook-up.  So, I would like to hear what suggestions you'all may have regarding heating the battery box to above the freezing point at least, considering we plan to have electrical hook-up available.  Ideas I have come up with so far is to place a work light with an incandescent bulb or perhaps a heat lamp in the box.  Another idea I am wondering about is locating a suitable heating pad of some sort.  I will be interested to hear ideas, suggestions and any product recommendations. Thanks.
You are correct that the Lithium must not be charged when the battery temperature is below 32*.  Note that this is battery temp, not outside temp.  Also battery temps above 100* F is not good for the batteries. Reduces the life.

Keep in mind the lithium battery does not need a vented compartment.  You can seal the old battery compartment to help keep it warmer in cold weather but then you may be concerned about hot weather.

A simple and efficient method to heat and possibly cool the battery compartment is to route a pair of 2" diameter flexible tubing from the interior of the camper to the battery compartment.  Install a 12V computer muffin fan to blow down the tubes to the compartment.  You will need to vent the compartment when you seal it up.  The computer muffin fan only pulls about 0.1 to 0.2 amps.  Wire a switch to turn on and off the muffin fan.

Lots of interesting links and info in all the replies I need to read. No time right now.
 
AStravelers said:
You are correct that the Lithium must not be charged when the battery temperature is below 32*.  Note that this is battery temp, not outside temp.  Also battery temps above 100* F is not good for the batteries. Reduces the life.

Keep in mind the lithium battery does not need a vented compartment.  You can seal the old battery compartment to help keep it warmer in cold weather but then you may be concerned about hot weather.

A simple and efficient method to heat and possibly cool the battery compartment is to route a pair of 2" diameter flexible tubing from the interior of the camper to the battery compartment.  Install a 12V computer muffin fan to blow down the tubes to the compartment.  You will need to vent the compartment when you seal it up.  The computer muffin fan only pulls about 0.1 to 0.2 amps.  Wire a switch to turn on and off the muffin fan.

Lots of interesting links and info in all the replies I need to read. No time right now.

Thank you for the tip.
 
Since there seemed to be some interest in my experience with the LI batteries I thought I would provide the latest.  I received my batteries yesterday as promised by the company (Battle Borne) and they arrived safe and sound.  I was impressed with how well packed they were.  I had a chance to speak with a tech and also Shawn (one of the founders of the company) regarding some specific questions on settings and general operation.  As a little background I have the Bogart Engineering Trimetric 2030 battery monitor and the Bogart Engineering SC-2030 charge controller.  As a stand alone charge controller without the 2030 BM it functions as a very basic charge controller, but in conjunction with the TM-2030 BM it becomes a very sophisticated charge controller with several operation parameters that can be programmed.  With the batteries I received a spec sheet which had the basic charging parameters of 14.2-14.6V charging voltage range and a recommended float voltage of 13.6 or lower.  The charge controller battery monitor combo allows for several other parameters relative to the charging performance that can be set and these parameters are what I wanted to find out from the company.  They were very thorough and helpful with providing the settings that will work best for these batteries as well as a general understanding what these settings mean in terms of how the batteries operate.  Shawn also indicated he knows the folks at Bogart Engineering well and is going to verify with Bogart on one of the settings.

The other question I had which may be of interest to this group concerns operating temperature and charging in cold weather.  The spec sheet provided indicated an operating temperature range of -4 to 160 degrees F.  What Shawn explained is the batteries can safely be used in this range.  As far as charging, I inquired about the 32 degrees I have been reading about and he indicated there is a range of 25-32 degrees F.  If the core of the batteries reach 25 degrees the BMS will not accept a charge until it reaches 32 degrees, so no need to manually shut down any charging systems.  I indicated my plan to put something in place to maintain a suitable temperature and he indicated if I were to go with a battery warmer, not to use a pad but rather a wrap, but went on to say an excellent solution is to insulate the box and put a light bulb in it.  I wondered about this as a choice, and he confirmed this will keep the batteries well above the 25 degree metric.

So far it has been a very good experience, customer service has been excellent.  I hope to install the batteries this weekend or next as I am finalizing the final connections of my inverter.
 

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