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Show HN: NiMH Battery Tester
- MarkusWandel 6y agoThere are other Arduino powerered battery testers, but this one is mine. I took some trouble with the documentation.
- adamfeldman 6y agoThis is awesome, I appreciate the docs! I switched to NiMH a few years ago and am so happy about the reduced waste.
- zelon88 6y agoThis is really, really cool. I might actually build one, but for SubC cells. I just bought a new 7c 5000mah NiMH pack yesterday for my Tamiya High Lift crawler because my old 5000mah is starting to go. I got about 3,000mah out of my last run according to my charger. But my charger has no discharge function, and if charging takes over 90m I must write down the MAH and restart the charger to start from 0. It can be frustrating. Your device would be very useful for me.
- MarkusWandel 6y agoKeep in mind this device relies on having access to each cell individually with all the negative ends being on a common ground. Battery packs, even with balancing connectors, usually have the cells hardwired in series.
- zelon88 6y agoThis is true but battery bars can be removed. I've got enough 5000mah SubC packs with one bad cell that I could probably make an entire good pack.
- watchdogtimer 6y agoNice work. How does this method of evaluating batteries compare to measuring a battery's resistance as found on some chargers?
- MarkusWandel 6y agoHmmm. Resources left on the board are: One Arduino I/O pin (the TX one), one unused relay. That could be used for one of the six channels to decrease the load resistance slightly by splicing in a parallel load resistor. By measuring the voltage drop from momentarily increasing the load, the ESR could be computed, at least roughly, for that one battery position.