E-Bike battery capacity testing
Last year I bought an e-Bike battery from eBay, and it's worked fine. It's rated at 36v/10Ah (amp hours) which basically means it can provide 10 amps for an hour at 36v. (Watt hours is a better measure of power stored in a battery, because the voltage of the battery changes between fully charged and empty but it seems Ah is more common.) I decided to measure how much power the battery would provide on a full charge, but this meant I would need a few things: a connector to match the one on the battery a power meter a way to use between 30 and 42v. The connector was fairly straightforward and after a bit of googling I discovered it was an M16 16mm 4 pin aviation plug so I grabbed one of those. Similarly a cheap power meter was easily procured from eBay. For the load I decided to use 3 12v car bulbs in series. These would have the ability to work at 10-14v each giving a combined draw of 30-42v, exactly the working range of my battery. Bulbs and bulb holders w