I live in Idaho, and it gets cold here! On a normal day, I'll through my charger and a few planes in the car and leave them there for the day. When I get a chance, I'll stop at a park and fly. That's fine, untill it gets cold. In the cold, the batteries don't perform near as well. It's said that you can loose 20-40% of your capacity in extreme cold. So how do I keep things warm in the winter?
While researching a few different things for keeping batteries warm, I came accross a massager at the thrift store. It had a built in heating pad, and vibrating modules as well. Being that it was only $5, I figured I'd give it a go. I pulled out all the electronics and found a nice little pad with resistance wire in it.
On this one, I tested the output module of the main unit, and it was outputting 16v. So, I can use 12v from my car to keep it somewhat warm, or plug a 4s pack in and keep it nice and toasty.
This is the pad, pretty simple really.
Installed in the Ammo Can charging box.
Hot glue keeps the plug in place (may need to replace with instamorph at some point).
On 4s, this pulls about 8.5 watts (.53 amps) and on 3s it pulls about 5.5 watts (.43 amps). Pretty efficient for my needs.
All in all, it should make for a good mod. There are various places to get heating pads, and I've listed some below.
Hobbyking Lipo Bag Warmer - Hobbyking even sells a Lipo Bag that does the same thing, it was just a little small for my needs. But very well priced.
Alternatively, you could buy some risistance wire and build it. I had very little experience with this, so this was the easiest option for me. I have also seen small 12v heating pads you can buy for around $20 that might do the trick as well.
My next project involves a Filing Cabinet, a warming pad for a pet bed, and sand. Looking foward to moving things to the garage for my all weather charging. (Sppiler Photo Below)