Hi,
I am looking to build an external hand held starter for a motorcycle engine. Figured this would be a good first project before tackling a powerwall.

The company calls for 2 lead acid batteries in series for 24 v with 900 cold cranking amps each and I want to build it out of 18650.

So the question I cant seem to figure out. My options:

1. Build a 24 volt battery with 900 Ah. Seems unlikely due to the size and volume of cells.

2. Build a 24 volt battery with 450 Ah since cells have a 2C max discharge rate. Seems likely since the battery would only operate for couple seconds at a time, but i could be at the limit of the cells and burn them up.

3. Build a 36 volt battery with 300 amp hours to get the same wattage just more volts for better cranking.
Please help.
Thanks!

I didn’t find the right solution from the Internet.

References: http://www.diypowerwalls.com/t-External-Hand-Held-Starter

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