Best Rechargeable Hand Warmers great little device to keep in your glove box, pocket, backpack, or purse to use as either a hand warmer or an extra battery to charge your phone. Of course, there’s no sense in buying this purely as an external battery since it’s more expensive than that kind of single purpose device, but I love that I can do either. I also have the nine-hour version, and while that feels better in my (small) hand and lasts longer, this one has the same capacity lithium ion battery. This one has dual-side heat only (with no single side option), but that’s the only setting I use anyway. The heat output is great, with five settings.
This hand warmer is not only great for camping or skiing but also for long walks during the winter. If you keep it in your glove box, remember to take it out occasionally to charge. The battery is built-in and rechargeable via included micro USB cable. If you have a phone with a different kind of power connector, make sure you also carry a short version of that for power transfer.
