Friday, December 04, 2015

USB Rechargeable Hand Warmer

Why Hand Warmers?
Marcus and Agata live in Lausanne, Switzerland.  It always snows at some point during the year, although this year of 2015 we are currently back to 10 degrees C afternoons again after the snows of 2 weeks ago.

When you are out hiking or walking in 0 degrees or even down to -10 degrees C colder Swiss winters it's useful to carry a small pocket sized hand or foot warmer.

A History of Hand Warmers

Traditionally there have been two types

Water Reusable
Here there is normally a bag with some thick liquid and what looks like a battery button cell inside.   You put the bag into boiling water for about 15 minutes and the liquid goes clear.

The you take the translucent bag on your trip and when you need heat press the button inside the bag.  A chemical reaction is started and the bag gets warm

One Off
Conversely you can buy a once off chemically reacting hand warmer.  It's warmer than the reusable one but very wasteful since after use you need to junk it after using.

The USB Alternative
I'm quite thrilled to have been recommended this USB alternative.

- It is charged up from a USB socket.  Annoyingly a standard mini not micro socket, but hey I am being rather picky here

- The claimed run time is 3.5 hours at 50 degrees C.   I would say well at least 2 hours

- The battery is 2600mAh and given I measured the charge current at 0.8A and 3.7W this means it will charge in less than 1 hour.

- Unit weight sans cables is 92 grams

 2600mAh rechargeable battery is included


You can use the heater to charge anything USB but you have to remember to take this cable (on the left) with you.  I'm going to lose it soon I know.

- This unit also has a torch LED but I'll never use it, rather my smartphone torch.

So far

Yes it works fine

I've been experimenting charging it with our recent bargain solar panel.  Yes, that works too

It keeps warm enough to heat hands for 2 hours

There are 3 LEDs to show charge level, but after full charging it drops from 3 to 2 LEDs in minutes, a small design defect I presume

For the 10 GBP   (15 CHF / USD) that I paid on eBay from user sun_mart  I can recommend this unit.