LED Battery Level Indicator

[Kc7fys] came up with a this simple battery level indicator. It uses a single LED to display a battery’s voltage; if the voltage exceeds 12V, it glows green. If it is below 11V, the LED glows red. Anything in between generates an orange glow. The meter is built around an LM358 chip per this schematic, but his actual build looks pretty sloppy because of the dead-bug assembly (check out NASA’s pretty version). Nonetheless, it works, so clean it up and build one if you want to put it (or your batteries) to the test.

Hack Your Prius With Prius Batteries


Adding extra battery capacity to hybrids is becoming pretty common, but this one is better than the average lead acid trunk fest. The pack was built from three prius NiMH packs picked up from salvage yards. These batteries can’t simply be bolted together, but with some research and effort you can save some nickel from the junk yards and cut your fuel bill.