As mentioned several times ‘eventually’ I aim to upgrade the battery to 72 volts to get better performance from the motorcycle that will push it’s top speed up to 120kmph (74mph). This performance would allow good A-road and viable M-road use.

The current 48v DC battery is ideal for prototyping because it is in the ELV (Extra low voltage) range at 50vAC or 120vDC hence is low risk to work with until all the wiring is correctly installed. It runs up to 47mph on conservative settings which is fine for urban use so no real rush to upgrade.

However, looking around, a popular battery supplier is Amorge. Looking at the stats of the 72v battery it is clear that there are some interesting options in terms of size and package for 200+ amp batteries. The current 350AMP Nissan Leaf battery is pouch based, but now-a-days it is much more popular to use cylindrical cells. In the case of the Amorge; 21700 cells (21mm diameter x 700mm length for each cell). Think they are great to customise form factors. Specs of the battery are below:

• Nominal Voltage: 72V
• Nominal Capacity: 44AH/ 3168WH
• Max Continuous Discharge Current: 275AMP
• Max Peak Discharge Current: 385AMP
• Charge Voltage: 84V
• Max Charge Current: 20A
• Cells: Lishen21700LA cells. (Other cells Samsung 50S, Molicel P42A are available)
• BMS: ANT BMS, Daly BMS, JBD BMS, JK BMS, ect.
• Sizes: 6X9X10.5 inches
• CE, RoHS Certificate
• Discharge connector: QS10 with 6AWG wire (customizable)
• Charge connector: XT60 with 12AWG wire (customizable)

As seen in the spec, the 6 x 9 x 10.inch form has more than enough juice to power the 8kw 50H V3 motor that uses 100a nominal (200a peak) and fits in the current battery box with ease, (pictured below). In fact the size is so small that I’d need to design and print a carriage to fill out the gaps. What is even better is that this package size includes an ANT BMS. I don’t anticipate doing this immediately but it is good to look around and see what is available.