His latest endeavor is a LiFePO4 battery charger that he made out of parts he had on hand for under $0.50 US. (Although we think he really made it for the fun of making it.) The circuit is ...

Even if you've never used jumper cables before, they're still an excellent way to get your car rolling again when you don't have a charger. Using jumper cables to revive a dead battery is a fairly ...