Battery Warming Method

[MapMaker53]

I finally earned my cold weather flying wings this past week, flying for 3 hours in 25F degree temps just hours before a major snowstorm hit the northeast. I had 5 batteries and needed a way to keep them warm. What I did worked really well. I placed a 1-gallon plastic container full of very hot water into a small picnic cooler along with my 5 batteries. This kept the batteries in a comfortably warm state until I needed to swap them. Naturally, I placed the batteries into a sealed plastic bag just in case the water container were to spring a leak. (Unlikely, but a possibility.) Wearing a lot of layers kept me toasty too. Flying in twenty five degrees wasn't as bad as I thought it was going to be.

 

[Ajkm]

The potential for a fire here strikes me as an unacceptable risk from a professional pilot viewpoint. Yes the batteries were in a "sealed plastic bag", but how would that hold up in "very hot water", and how submerged would they be if 1 gallon of "very hot water" flooded the cooler. The possibility of the jug rupturing, no matter how remote one might think it would be, would certainly come within any legal definition of "reckless", if not "negligent", I would think, given the added level of safety required around this type of battery. I don't think any regulating or investigating body would consider that any "risk mitigation" had taken place in this scenario - and any description of this in an application for a waiver (SFOC in Canada) would, I imagine, fail the safety test.

 

[MapMaker53]

Well I certainly wouldn't check it onto an airline, but I found it perfectly safe for a field assignment. And, as far as I know, I am not required to describe my battery storage method in any type of FAA waiver. The sealed plastic bag protects the batteries, and the temperature of the water was certainly not high enough to even come close to compromising the thick plastic container or melt a plastic protective bag. But you are certainly entitled to your opinion regarding this method. I found it to be a simple and effective one for field use Honestly, I would have used a hand warmer or two in place of the water jug, but I had none on hand.

 

[Ajkm]

A dry hand warmer would be preferable to anything containing water imho.

 

[dempseycreekkid]

maybe some warm potatoes? ha ha from idaho.

 

[MapMaker53]

maybe some warm potatoes? ha ha from idaho.

Haha yes I'm sure warm potatoes would work. The key for field work IMO is to use a small insulated cooler with something very warm inside to keep multiple batteries from getting to cold during the course of a few ours out in cold weather. A couple of batteries stored in an inside pocket of clothing works, but when you need more than a few batteries at the ready, I found a warmed cooler environment is very convenient.

 

[BigAl07]

Hey it worked and you competed the job safely.

Honestly, I never would have thought of the "water jug" as my thermal storage but it works. The plastic bottle was one layer of protection and individual bags were a 2nd layer. Works for me if that's how you gotta do it.

We use a cooler but use Hand Warmers. Initially we used the Iron Oxide (Hot Hands brand) type and put them inside a sock to reduce "burn rate" and add a layer of thermal protection (can hit 130deg) to the plastic in the cooler. This worked great but then we discovered "Chemical Reaction" hand warmers that are reusable. Click the metal disk and the warmer starts crystalizing and giving off heat. We'd drop 1 per hour and it kept everything in the cooler toasty warm. After a day of use you simply boil them for a few minutes and they are ready to go again.

 

[MapMaker53]

Hey it worked and you competed the job safely.

Honestly, I never would have thought of the "water jug" as my thermal storage but it works. The plastic bottle was one layer of protection and individual bags were a 2nd layer. Works for me if that's how you gotta do it.

We use a cooler but use Hand Warmers. Initially we used the Iron Oxide (Hot Hands brand) type and put them inside a sock to reduce "burn rate" and add a layer of thermal protection (can hit 130deg) to the plastic in the cooler. This worked great but then we discovered "Chemical Reaction" hand warmers that are reusable. Click the metal disk and the warmer starts crystalizing and giving off heat. We'd drop 1 per hour and it kept everything in the cooler toasty warm. After a day of use you simply boil them for a few minutes and hey are ready to go again.

Thanks for the tip, BigAl07!