4s3p Battery Spacer A123

thingiverse

This is a spacer for a 4s3p Battery Pack. The pack serves as a battery for my Buell XB12, but it can be used on any motorcycle provided you check that the on board voltage does not exceed 14.4 Volts at any time. I chose Lithium Werks (formerly A123) ANR26650M1-B cells due to their extremely high pulse current capability and robustness. These are LiFePO4 cells, which means they are less volatile than LiPO cells. They do not explode as easily and can withstand over voltage for short periods of time without dying or catching fire. Most commercial LiFePO4 packs use these cells as well. A 4s3p pack of ANR26650M1-B cells results in: Voltage: **13.2V (nominal)** Capacity: **7.5Ah** Current: **150A** Peak Current (<10s): **360A** This should be sufficient to start a big V2. If you have a smaller engine, a 4s2p could be enough. I also connected a balancing connector. Balancing is not necessary but with a connector you can at least check if the cells are still in good shape. **If you don't feel comfortable handling a soldering iron or are not used to handle electronics, I wouldn't recommend building a pack on your own. You won't save much money compared to a commercial pack and you can easily destroy the cells or hurt yourself while soldering or if you accidentally cause a short.** I tested it with an electronic load at work. 170A is the limit of the load and voltage measured directly at the pack was still over 11V after 10s (voltage in the picture is at the terminals of the load, with very long cables and 3 connectors in between). Temperature inside the pack rose to about 40°C. So it looks like a success to me. Testing in the motorcycle will follow in spring.