Bosch 36V Ebike Battery connector & DIY 2A Charger

thingiverse

I wanted to be able to charge my Bosch Powerpack 500 battery in my car when I'm on trips. Unfortunately the standard 4A Bosch charger pulls 170Watts which is more than my car's AC Inverter can support. I also tried to use my 300Watt Pure Sine Wave Inverter, but my cigarette lighter socket only supports 120W. So I decided to build my own 12V 2A Bosch Ebike battery charger. A side benefit is that I can adjust the maximum charge voltage. You can set it to 80% and get more cycles out of your battery. Designing the Connector was relatively easy. You can use standard spade connectors from the hardware store. The hard part was figuring out how to put the Bosch battery into charge mode. It turns out to be pretty simple (It always is after you figure it out ;-). You just have to supply 5VDC on the third pin. I was able to find DC Boost converters on Amazon. The first one I chose did not even closely meet their specs. I had to down grade the charge current to 1.3A and the temp was still 112F. I ended up going with a more substantial (and more expensive) boost converter. Items used: * Bosch Powerpack 500 Battery ( https://www.bosch-ebike.com/us/products/batteries/ ) * 1500W boost converter ( https://amzn.to/2KQxC4I ) * 12V to 5V converter ( https://amzn.to/3nEYtza ) * 10A male cigarette socket plug ( https://amzn.to/3aCdUnV ) * 10Ga Stranded Copper Silicon wire ( https://amzn.to/2M1XBXv ) * Ace Male Disconnect 12-10AWG ( https://www.ebay.com/p/1900956207 ) * Ace Male Disconnect 22-16 AWG 0.187 In tab ( https://amzn.to/3mBrw5n) * Wire Crimper ( https://amzn.to/3igwTog ) * Wire Stripper ( https://amzn.to/33lQak4 ) 150W boost converter that did not meet specs ( https://amzn.to/3mGbqrd )