We’ve reviewed quite a few Apple Watch chargers over the years, but the Oittm charger is the smallest charger that I’ve seen. This charger is so small that you can attach it to your keychain or carry it in your pocket.
This keychain-sized power bank is compatible with all versions of the Apple watch and has a built-in Li-ion battery with a capacity of 700mAh. If you’re thinking that 700mAh is not a lot of juice, you would be thinking correctly. The Oittm charger is not going to fully recharge your Apple Watch. But it will top it off and/or add up to 3 hours of extra running time to the watch.
You’re not going to use the Oittm as the primary charger for your Apple Watch, but it could come in handy as an emergency charger if you’re off the grid and need to revive your watch before you can get back to your regular charger.