offgrid-curious
New Member
While waiting for my custom insulated metal battery box to be built, I decided to build a custom temperature controller. I'm planning on heating an aluminum plate which the cells will sit on. Rather than use heating pads, I bought 5m of 15ohm heating wire on Ali Express for $6 and received it within a week. I like the idea of heating wire more than pads because I can run the wire across a greater area of the plate so ideally the heat will spread more evenly.
For the heat controller I used an NTE-DTO60 thermostat, rather than one of the fancier digital temperature controllers. The thermostat will open the circuit when it's above 60F, and close it below. It's nice because it can use my native battery voltage (48v) without stepping down. Also, it's a simpler component that I think would be less likely to fail. While I don't have precise temperature control, I think it should be good enough. I put it into a small case with a power switch and added an LED to indicate when the heater is on. I put a few holes into the side of the case for ventilation.
I made a mistake when I initially put it together -- I used a single 2200ohm resistor, not realizing it was only rated for 1/4 watt. When I tested it, the case was surprisingly warm and I noticed a slight burning smell
but the resistor somehow survived. I ended up putting 6 resistors in series to spread the load. I tested it again (by putting the controller in the freezer for a few minutes) and it seems to work as expected!
For the heat controller I used an NTE-DTO60 thermostat, rather than one of the fancier digital temperature controllers. The thermostat will open the circuit when it's above 60F, and close it below. It's nice because it can use my native battery voltage (48v) without stepping down. Also, it's a simpler component that I think would be less likely to fail. While I don't have precise temperature control, I think it should be good enough. I put it into a small case with a power switch and added an LED to indicate when the heater is on. I put a few holes into the side of the case for ventilation.
I made a mistake when I initially put it together -- I used a single 2200ohm resistor, not realizing it was only rated for 1/4 watt. When I tested it, the case was surprisingly warm and I noticed a slight burning smell
but the resistor somehow survived. I ended up putting 6 resistors in series to spread the load. I tested it again (by putting the controller in the freezer for a few minutes) and it seems to work as expected!
