Solar / LiFePo4 batteries and the Cold.

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GeraldTheBonzai
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Joined: Fri Oct 08, 2021 7:52 pm

Solar / LiFePo4 batteries and the Cold.

Post by GeraldTheBonzai »

Currently trying to work out how best to insulate my batteries.
My solar rig feeds into a 280Ah LiFePo4 battery. The BMS in this specific battery (EcoWorthy) will still charge when at around -2C. The battery is outside in the shed and for the first time this season, last night it got down to around 1C outside.

Now I only charge the battery, obviously, in the day when sunny, at which point the temperature in the shed is normally above 0C (at the moment). However am think about the scenario where we might have an extended cold snap and I need to charge the battery but its below 0C. I can't have something like a diesel heater in the shed - got stuff in there that wouldnt play nicely with it. So options are either to insulate the battery to reduce heat loss, or build a heating pad (which is a strong contender - I have the bits I need).

So people with solar rigs. What are you doing to ensure that you can charge your batteries if the temperature drops below freezing?
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pseudonym
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Joined: Wed Jul 27, 2011 10:11 am
Location: East Midlands

Re: Solar / LiFePo4 batteries and the Cold.

Post by pseudonym »

All my Jackerys are indoors. I do have an electric radiator that I would use if they were in a location where low temps were expected.
Two is one and one is none, but three is even better.
GillyBee
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Joined: Tue Apr 07, 2020 6:46 am

Re: Solar / LiFePo4 batteries and the Cold.

Post by GillyBee »

One of the Renogy batteries options includes a self-heating system for cold weather use.
Our rig is also in a shed and I was thinking about what I could do if we get a bad cold snap - especially if that triggers power outages. I have a heat mat for my propagator - circa 15w which I could use in a pinch plugged into the invertor. It has a thermostat control in it so I could keep it turned down to a minimum level and hopefully avoid draining the battery trying to keep it warm.
Worst case the battery would be sharing the hot water bottles with the humans.
GeraldTheBonzai
Posts: 605
Joined: Fri Oct 08, 2021 7:52 pm

Re: Solar / LiFePo4 batteries and the Cold.

Post by GeraldTheBonzai »

GillyBee wrote: ↑Sat Nov 14, 2026 9:48 pm One of the Renogy batteries options includes a self-heating system for cold weather use.
Our rig is also in a shed and I was thinking about what I could do if we get a bad cold snap - especially if that triggers power outages. I have a heat mat for my propagator - circa 15w which I could use in a pinch plugged into the invertor. It has a thermostat control in it so I could keep it turned down to a minimum level and hopefully avoid draining the battery trying to keep it warm.
Worst case the battery would be sharing the hot water bottles with the humans.
Actually, that's a really good idea. I have all the bits to make a heating pad, including the controller. However, it would mean building something from scratch. A heating pad for a propagator would come ready built and likewise i could just plug it into the inverter. Whilst you shouldn't charge a battery below 0C, you can still draw on it. I also have the backup rig, which uses AGM batteries, plus I have a small MSW inverter somewhere.
So basically warm up the battery using itself, then charge when warm... Like it :D
GeraldTheBonzai
Posts: 605
Joined: Fri Oct 08, 2021 7:52 pm

Re: Solar / LiFePo4 batteries and the Cold.

Post by GeraldTheBonzai »

oops double posted..