Hello. Thought it would be useful & fun to tell my story here on this forum. And for those interested in building a great ebike, follow the lead. I built a working 500 watt 36 volt ebike without incident, first pass and so can you. It just takes forethought, research, quality components and follow through.
The battery is in my estimation the most costly and prone to error component, so this thread concentrates on building the best of the best - an A123 AMP20, as in 20 amp-hour, nanophosphate LiFePO4 battery pack. Mine is 12S for 36 volts, but it can be 24V, 48V, 72V or whatever your motor demands. See A123 AMP20 Cells, new, legit, factory direct!
for sourcing cells.
It became obvious from reading other stories of people building battery packs, looking at their pictures and the comment stream, that life would be simpler with a the right design, parts, tools and construction methodology. Enter Agniusm's A123 AMP20M1HD-A Battery pack kit
. The rich picture set, videos and post stream convinced me this was the way to go.
There appeared an opportunity to snag one of these 12S kits in his first engineering run, so on Jul 26, 2012 I first made an inquiry on availability
. Sure enough, he had one, and if I acted fast, he'd have it shipped immediately. So, yea, I coughed up the dollars (the magic of Paypal) and got it in the mail a few days latter, adding my name to docnjoj, deVries, ohzee, 999zip999, eva-michael, megacycle and others taking the unique advantage of the simplicity of great engineering, and tacitly agreeing to being guinea-pigs, as Agniusm perfects his desgin & manufacturing
for the cost of my pack.
To BMS, or not to BMS, that's an important question for everyone. Really, the underlying question is how to keep your battery pack healthy and thereby extend its life. There's a lot of information on the forum. My favorite is BMS-Free, info for the curious on bypassing the BM-mess
and dogman's suggestion that a "human BMS" is a valid approach to protecting a battery, the approach I'm taking. Its part KISS, frugal and more informative.
Jump to HERE
for information on how I charge my battery pack.
Cautionary tales of fires