Renogy Smart Lithium Battery with Self-heating

SolarShed

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Jul 20, 2021
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108
So have you sorted out what happens when it's dark/no solar and your batteries get colder than -20c? In theory the Renogy shuts down. No discharge ! Nothing will work. I have a small RV that needs power to run my blower for the furnace. If the battery get's to -21, I have no heat. Can't start the generator as I need battery to start.
This could be a bit dicey. I haven't hit - 20oC yet. Your only hope is that you're pulling at least 4 amps from the panels in the sun, the charge controller would be running on solar panels only at this point, which is not good for some controllers.

I'm finding that this battery pulls 4 amps when it tries to check to see if there is enough current to start the heaters. If the current is not enough it turns off, tries again later. I'm trying to find out how often it does it and for how long, because there are days where my panels can't even pull 4 amps due to clouds, snow, ice.

What could happen and I'm only guessing this, is that when you're at -20 and your charge controller is running off the panels only, the battery will do it it's 4 amp check for current, and your only hope is that the sun is shining at that time.
 

Yurtdweller

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Nov 23, 2020
Messages
129
This could be a bit dicey. I haven't hit - 20oC yet. Your only hope is that you're pulling at least 4 amps from the panels in the sun, the charge controller would be running on solar panels only at this point, which is not good for some controllers.

I'm finding that this battery pulls 4 amps when it tries to check to see if there is enough current to start the heaters. If the current is not enough it turns off, tries again later. I'm trying to find out how often it does it and for how long, because there are days where my panels can't even pull 4 amps due to clouds, snow, ice.

What could happen and I'm only guessing this, is that when you're at -20 and your charge controller is running off the panels only, the battery will do it it's 4 amp check for current, and your only hope is that the sun is shining at that time.
Ok, so, I'm in Texas, near Houston, and thought, I'll never have to deal with long, deep cold🙄 then last January happened. I was caring for a loved on in the hospital, and did not hear about the big freeze warning until two days out. I had just one little 100ah prismatic LiFePo4 pack at the time. I jumped on Amazon and grabbed a seedling mat heater(110v model). It came just 6 hours before the ice storm hit. I wrapped it around my pack, and wrapped foam board and blankets around the whole kit. The heater is very low watts. Idk exactly the numbers right now, but it was inconsequential. Under 50 watts, I think, and intermittent. During the ice storm, my panels were cranking more amps than my scc was rated for, and I actually damaged my 40 amp Renogy Rover. It hit 43 amps at one point. My battery never hit either a low or high temp warning, and never shut down. The seedling heater has a programmable digital readout on a cord, so that the controller can be outside the blankets, and the heater and temperature probe can go wherever you want them within three feet. Seedling heater is thin hard plastic, with no sign of internal cables, and can apparently handle the weight of a small battery. If I use it with my 280 or 540 ah pack, I will use spacers so that the pack is not directly sitting on it. If your Renogy smart battery is not performing as you wish, you could always add your own external heater. The external will run off battery juice and an inverter at night, as long as your battery has juice. I just wish I could find the equivalent in a 12v device, but I haven't found a 12v with a precise thermo control, yet.
 

SolarShed

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Jul 20, 2021
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108
good story. Yeah, I guess that cold hit Texan's pretty unexpectantly. Good that you managed to make it work for you.

My battery is doing well, its also wrapped in 2 inch thick foam, and its makes a big difference. When its -31oC the battery is around -17oC.

I had to use a LFP charger several times so far because we are in winter solstice, the sun is very low, its cold and its been cloudy so my panels are not producing enough to even activate the heaters. I'm currently in the process of adding a 5th panel so that it faces south, where I can get a good 3 to 6 hrs of sun, even now.
 

Sky Noris

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Joined
Sep 13, 2021
Messages
12
I've got my Lifpo4 bats in a shed that I insolated just before winter . It's made it through some fairly cold nights where the temps dropped below 19F / -7 C so far. I added a electric heater for around $25 used off amazon. It connects to my wifi so I can monitor and control it easily. draws around 1KW when running and turns on about 10-15 times a night. Consumes around 1.5 KWH per night on average. Not sure how it will hold up though when it gets much colder. Or if I have 5-6 days in a row will little sun. But with this system I'm able to keep my bats around 44F- 50F consistantly.
 
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