Bought 4 of these. (2 come in a box) the tops were coming apart couldnt charge them. Bought 2 sets a year ago and they worked great kept my hands warm and was able to charge phone etc with them. Quality has gone down on this product.

I have one unit very first use a stuck button won't turn off last time was at night I had to drive so set with light on in my glove box . I like to product if working but has defects apparently may just return units

Love it. I have neuropathy so my hands are cold most of the time. These handwarmers are muscular; time + heat + power. Better than others costing twice as much. Fast charging for my phone, long term heat for my bones; put it in the bottom of my sleeping bag for all night warmth. I don't think it will trickle charge will solar or car battery. I'd like to know.

These are great handwarmers when you can get them to work. Having only 1 button to control multiple functions is rarely good. It's a NIGHTMARE when you can't turn something off. First of all, the button is NOT easy to access. It should not be this difficult. On occasion, the flashlight function triggers while trying to shut off the heat. It is then 10 - 15 minutes trying to come up with the combo to turn it off. I have not yet needed these to be power sources, but draining the power attempting to cancel the flashlight can't be productive. 3 stars for handwarming, unknown for power source, ZERO for flashlight.

Work great for spring softball season.

Great product! Heats fast. Long life.

Great hit for Christmas present

Simple to use. It gets warm very fast and the battery lasts all day.

Works great at warming my hands

finaly hand warmers that work