I recently purchased a Nitecore LC10 to use as a travel battery charger, so I thought I would share some information about it because in a way it is an electronic multitool (3 in 1).
The main reason I purchased this is to use as a li-ion portable battery charger. I primarily use 16340 batteries and wanted an easily packed charger. The LC10 is not much bigger than your average power cord, so it is easily packable. It will only charge li-ion batteries, so if you use nimh it won’t work for you.
In addition to using the LC10 as a magnetic usb charger, it can also use a charged battery as a powerbank. If you have a charged rechargeable li-ion battery, you can use the LC10 with the battery to charge a device powered by a micro usb, like a phone. Mine also came with a micro usb to lightening adapter so I can charge my iPhone with it.
The charging indicator on the LC10 is also an LED light. It is not real bright, but if you have a battery you can use it as an emergency light.
The LC10 (with the micro usb to lightening adapter that jot all come with)
LC10 with an 18650 battery being used to charge a keychain flashlight
Olight has a similar magnetic charger. The Olight charger is only a battery charger and can not be used in reverse to charge another device. But the Olight charger can also charge nimh batteries, instead of just li-ion like the Nitecore LC10.