$20 P3 DIY battery warmer

[Cale262]

With the cold weather we've been having and DJI's suggestion that batteries be heated up to 25*C or warmer before flying I found it weird that I couldn't find a battery heater for a reasonable price. DJI does makes a nice heating unit for the Inspire batteries but no love for my Phantom 3, this lead me down the DIY path. I started to look for a 12v solution as I intended to use this heater while I was out and about in my Jeep. I was initially thinking I might use an automotive battery blanket but all that I found were non-adjustable and ran 65*C and warmer, way too hot for my little P3 batteries. I then realized that my Jeep and most newer vehicle manufacturers are nice enough to add a 115v power supply and this was perfect to run a small therapeutic heating pad which I found on sale for about $15. Now all I needed was a small box to put it in. It didn't take me long to a nice Plano box on sale for $5 and I was set.

Cut a quick notch in it for the cable to run through,

Stuff the heating pad into it and I had a pretty good $20 battery warmer that fit four P3 Batteries just perfectly!

Drill a few holes, add some zip ties and clean up the wire mess a bit...

 

[Kranmc]

Seems like a smart idea. How sure are you the temp stays at the recommended level and doesn't get too hot?

 

[Cale262]

Seems like a smart idea. How sure are you the temp stays at the recommended level and doesn't get too hot?

I'll certainly be watching it the first time I use it and I think I may even add a digital thermometer for an aquarium that I have kicking around here somewhere.

 

[BVC]

I thought about this. I actually threw a couple movers blankets in the back of my SUV (harbor freight) for random nonsense that comes into my life where it'd be nice to have a blanket. My take on the battery warmth in colder temps is - your heating pad/box is good when there is power. My Vehicle has a built in power inverter to make this work but.. I decided that placing the batteries on my heated seats (rear seats are heated) with the blanket over em is a good toasty way while leaving my 110v outlets free for charging other items (maybe the batteries while in travel).

I noticed one day I went up to a lake about 40 minutes away from me. Typical fall day in Cali - Sunny & 70 degrees. I flew my drone around a dam and got some great shots. I took the two batteries and placed them inside my case to transport back up to the SUV/home.

Upon my arrival at home I removed the batteries to find they were still hot! Not luke warm but nearly the same temp when I yanked them out of the phantom up on the mountain.

Summary? Heat the batteries by any means in cold weather and if you have a decent setup in your case it may help retain that heat for your use out in the field.

That's my setup.

 

[Cale262]

Seems like a smart idea. How sure are you the temp stays at the recommended level and doesn't get too hot?

Just finished a couple quick tests, both conducted in an ambient temp of 20*C both by placing a thermometer in the case for one hour.

1st. switch on warm equaled a inside temp of ~ 28*C or 76*F
2nd. switch on high equaled an inside temp of ~ 38*C or 100*F

With those results I think I'm going to be pretty safe using it at colder ambient temps but I'll try and get some actual field testing done in the next day or two as the daytime highs are going to be ~ -17*C/0*F and the amb.temp in the back seat of my Jeep where my batteries usually travel should be around 10*C/50*F

 

[BVC]

I'm sure you already thought of it but of course there is the 12v heating pad option which removes the need for a power inverter (if your vehicle doesn't have a 110v power outlet)

Amazon.com: Trillium Worldwide TWI-2202 12V Heated Travel Pad: Automotive

 

[Gaffer]

That is a great setup.

An old trick I learned from a Camera Assistant for keeping Camera batteries warm when on Location in Alaska, which is similar to Cale 262 setup, but requires no electricity.

He would take a small cooler (think six pack size) and throw in some handwarmers. He used the Zippo style that used lighter fluid, but I have used the chemical style as well. Best part about this being you probably have most of the parts you need lying around the house. So if you are hiking in or skiing someplace you can keep your batteries toasty warm.

Here is the Zippo handwarmer:

Amazon.com: Zippo Hand Warmer High Polish Chrome Pocket Lighter: Sus: Sports & Outdoors

 

[phantom13flyer]

Very nice idea!! I think I might build the same thing . Thank you

 

[BigAl07]

I was flying today at a local ski area and the temp was 18deg. I kept my batteries heated in a small soft sides cooler and a 4 iron oxide hand warmers tossed in there. The batteries were all warm and toasty when it was time to change batteries and I flew all 4 with no problem at all. With that said I am going to try the Heating Pad method except I'll opt for the 12v option as my car doesn't have 110V in it.

Cale 262 where did you get the PLANO case for $5?

 

[AL T]

Harbor Freight has them

 

[Cale262]

...Cale 262 where did you get the PLANO case for $5?

I purchased it from a local department store called "Canadian Tire", It's a very large chain in Canada but I don't usually buy anything from them unless it's on sale or I really need it because if I buy it today for full price it will be on sale tomorrow for 50% off. This was the case for the box, regular price was $10 and the day I was looking it just happened to be half price.

 

[oakmeadows]

I use maplins in car ceramic heater code A75FL for £9.99 it's a steal just plug it in the ciggy lighter and off you pop luvly gubbly



Sent from my iPad using PhantomPilots mobile app

 

[neven]

I put batteries on a floor on passanger side and turn car heating to legs. Works. 0$


Sent from my iPhone using PhantomPilots mobile app

 

[Sinisalo]

That is a great setup.

An old trick I learned from a Camera Assistant for keeping Camera batteries warm when on Location in Alaska, which is similar to Cale 262 setup, but requires no electricity.

He would take a small cooler (think six pack size) and throw in some handwarmers. He used the Zippo style that used lighter fluid, but I have used the chemical style as well. Best part about this being you probably have most of the parts you need lying around the house. So if you are hiking in or skiing someplace you can keep your batteries toasty warm.

Here is the Zippo handwarmer:

Amazon.com: Zippo Hand Warmer High Polish Chrome Pocket Lighter: Sus: Sports & Outdoors

that is what I do too, but I use the DJI trick and heat a bag of dry rice in the microwave and throw it in the cooler, Your batteries have to be in a ziplock though with all the air pushed out or in the DJI cardboard and foam package the new ones come in or they get condensation on them.