Hi guys quick question is anyone heating their batteries? Im going to have my batteries in my garage which is more than likely going to see some really low temps in the winter being out side the houses domain. Is there some products? Are some of you using electric heaters?
My batteries are in unheated building with temperatures in winter dropping down to -15C.
I have build a hard Styrofoam box (5cm thick walls). As heating element I used an infrared 60W incandescent bulb. This bulb is heating a aluminum radiator block. Inside is also fan to move the air.
Thermostat controls the bulb and keeps the temperature inside at 20C regardless of how low is the temperature outside. At -15C this bulb is on maybe for 3 or 4 hours a day.
@Daza I have to heat my batteries in the winter. Im my garage, it drops to 0*C and if the batteries get that cold, I lose about 25% useable capacity. I have a 150w heating element at the bottom of the photo pumping the heated water though the batteries, the tesla batteries have a heating / cooling loop built into them. Heater is set to 32*C and the water thermostat is set to 26*C so I get 25*C inside the batteries. The electrical energy used is far lower than the useable capacity gained.
Wow thanks guys you both have good heating setups, I won’t be able to do the water as no room for the heater to run upwards, the bulb idea what is it like in the summer. I was thinking just an electric fan heater but you guys have been super conservative on the power that your using to warm the batteries I might have to rethink my electric heater thing.
Update: I might look at inferred options for both size direction and energy efficiency probably the nearest I would get to you guys energy efficiency rather than a blower style heater.
In the summer when temperature gets up to 30C the lid of my box is lifted to ventilate out the heat generated from batteries as they work. The fan inside this box is on all year.
Below is battery temperature graph for the last 6 months.
In winter temp never goes below 20C as this is the optimal for LFP cells.
You can set the minimum temperature lower if you want to conserve the energy.
During the spring and summer the heater is off and you can see that sometimes the temperature goes below 20C when is a cold spring night. :)
My box was made by me out of hard Styrofoam used for isolating building foundations. All walls of the box were glued together except the front and top.
Front wall is attached with screws for easy access to the batteries just in case I need it. Top is not attached so I can lift it open in the summer.
The fan is actually made out of two 12V fans taken out of computer power supply.
12 V source for them is inside the box to utilize all heat generated by the system.
Air is not taken from the outside of the box. Fans only keep the air circulating inside the box.
There is a space around batteries for air to circulate. Air circulate only around the sides to keep the air flow constricted to the batteries sides.
The heat is lifted by circulating air from the fins of the radiator block that lies on the bottom of the box right under the bulb.
Fans are one on top the other and are located on the opposite end to the bulb and a radiator.
It took me around 3 hours to build it.
Below some pictures:
just finished the box just need to cut the lid so it sits in I’ve tested the infrared bulb and must say it works really well the Batteries will be on Pylontech mount brackets that stack so airflow all around each battery just wish for a better minimalistic way to keep them warm and have good aesthetics
The heat is very concentrated
And the bulb will eventually fail.
An electric warming mat is a great alternative.
In my system bulb is heating the aluminum radiator and air circulating around batteries is heated by this radiator.
@mvas It is easily sourced from anywhere and cheap that you wouldn’t even blink, yes heat is very concentred from a bulb but the bulb isn’t heating the battery itself but the air inside the box which is easier and cheaper than heating my house whole garage, a fan turns on at the sametime to circulate the air, the heater mat would have to go under every battery which would be on the case of the Pylontech batteries so not sure how effective it would be through the Pylontech housing and I would still need the box in order to stop it heating as many as times wasting all the batteries stored energy in the winter months when solar isn’t as good
