[Eggmont] was facing this dilemma with a Makita battery from ... decided to make a USB charger out of it. [Eggmont] took the simplistic approach, using an old cigarette lighter-to-USB adapter.

The charger slots into your car's cigarette lighter and includes two built-in ... LISEN says a quick 30-minute charge can get you up to 90% battery life; in our experience, we've gotten closer ...

But, while it’s tempting to grab a cable and use the USB port, you might well find your smartphone battery ... USB chargers tend to deliver 5V, the 12V available from the lighter socket means ...