Keeping LiFePO batteries warm in the winter....

[TOU47]

As noted in a recent thread, I recently bought 1 PowerPro & plan on buying 2 more to add to our system once the house is finished. Obviously these all have built in heaters. However, I also 6 LifePower4's that need to be kept warm that are kept in my insulated solar utility room which is kept separate in a 20' shipping container. This is also where we have an inverter & a fridge/freezer.

While generally the inverter & fridge/freezer put off enough heat to keep it warm enough in there, sometimes we see -10⁰F (-23.5⁰ C) where the inverter & batteries are & it is not enough with the limited insulation we have in there. We have wired outlets in there so we then plugged a $15 Thermocube plug (powers on 35⁰-45⁰F) & then put a $24 1,500W ceramic heater plugged in to that. We also have a wireless temp monitor in that room so we always know how warm or cold it is in there.

There has been no problem keeping it warm in that room. The only exception was when something accidentally got put in front of the heater. The safety on it was triggered when it got hot (thankfully) & then had to reset it & turn it on fully the next morning for a little while... no big deal. Pretty inexpensive solution.

 

[Andrewr05]

Yeah, it really doesn't take a whole lot to keep the batteries at the right temp.
Bringing them from already being at frozen temps up to operating temperature takes a lot more energy then keeping them insulated and disallowing them from getting to those freezing temperatures in the first place via a heater though.


That's a good solution.

 

[Rednecktek]

A neat trick I've seen is getting the pipe warming heat tape for water pipes and wrapping that around the battery. The one I have on my water pipe only comes on when it gets close to freezing and ramps up the power draw as it gets colder, but never draws enough to get the pipes too hot. A lot less piwer draw than a 1500w heater trying to warm the entire room when the battery is the important bit.

 

[TOU47]

A neat trick I've seen is getting the pipe warming heat tape for water pipes and wrapping that around the battery. The one I have on my water pipe only comes on when it gets close to freezing and ramps up the power draw as it gets colder, but never draws enough to get the pipes too hot. A lot less piwer draw than a 1500w heater trying to warm the entire room when the battery is the important bit.

Nice, that is pretty interesting; definitely something to think about. While it may be more energy efficient for 1 battery, with 6 batteries to heat it may not be as cost effective?

Also while it initially sounds good in theory, since it doesn't really effect the ambient temperature of the room when the temperature is constantly freezing, I would think it would have to constantly run x6 24x7. I would have to think & experiment with that too know for sure.

That said, for around $40, I know the above works very well & has allowed me to additionally store other temperature sensor items in the room as well.

 

[TOU47]

Yeah, it really doesn't take a whole lot to keep the batteries at the right temp.
Bringing them from already being at frozen temps up to operating temperature takes a lot more energy then keeping them insulated and disallowing them from getting to those freezing temperatures in the first place via a heater though.


That's a good solution.

% agreed. Also very true trying to keep them warm constantly when it is sub-freezing temps 24-7 outside which it usually is in the winter at 7,000' in Colorado winters. I feel this solution has addressed ambient temperature for me before it ever gets to be a problem & is easily scalable with 1 or +18 batteries for the same $40 total.