With the USB charging adapter attached to a regular 5 AH Makita battery I was able to charge 2 Mini 3 Pro batteries from 50%-100%. It took about an hour for each one and drew down the Makita battery to about 50%.

For people who have tools from Makita, Dewalt, Milwaukee, etc., and have a USB adapter, here's a ready made solution for charging when away from shore power as an alternative or in addition to battery banks.

Congratulations, you have just discovered the power bank.

LV_Forestry Posted at 1-4 22:21
Congratulations, you have just discovered the power bank.

Well yeah - I admit it's a pretty low brow red neck solution - but for folks who already have these things - it's a very doable one in the field.