This fun feature can be found in a few of Makita's battery chargers, such as the 18V LXT Rapid Battery Charger and the 40V ...

So, what if you're left with a lower voltage charger and a battery that requires more than double that amount? Looking at Makita brand's 40V battery compared to its 18V charger, you can get a ...

[Eggmont] was facing this dilemma with a Makita battery from a broken angle grinder and decided to make a USB charger out of it ... so it was fine to use it with the 18V tool battery.