I just built one with recycled laptop batteries... super fun to ride. It was a shit ton of work to do the batteries right, but I learned so much. Endless-Sphere is where my build thread is...
My bike is 2004 Specialized mountain bike. Bought the motor from ebay and just bolted it on. The battery lives in a home sewn bag I made which I velcro strapped to the frame. I have gone about 35mph on it. Do not recommend super high speeds unless you are a capable bike rider.
It looks like a mad max experiment. I just wanted to ride the thing and wire management is def an afterthought. I do not ride anywhere I can't take it inside with me even though I only have about $500 into it. Too much work to risk theft.
So much fun to ride. Peeling out in dirt is thrilling on bicycle.
I've been thinking about doing the same thing but am worried it will explode on me. Are there any tips you have for starting out or mistakes to be sure to avoid?
I was hoping to use this as a project to learn electricity with and it sounds like you did something similar.
This is exactly what I did. I wanted to learn DC circuits and battery technology and I did that in spades.
Batteries are really simple, just need to respect them. If you are going to use recycled batteries, I suggest you buy a Opus c3400 tester. Run them through a complete charge/discharge cycle to identify capacity and bad cells. If they get hot, take them out and properly recycle them at Autozone. Otherwise, write down the capacity on the cell.
You can use repakr once you have 100 cells or so. I went with a 13s6p configuration for a 48volt system. I learned a ton from Micah Toll's DIY Lithium Battery book. Also, register at Endless-Sphere and start reading. Eventually the information will coalesce and you can start to buy bits and bobs. Take your time and don't rush buying right away... lots to learn.
There's usually no explosions, they burn vigorously.
But before that they get too hot to hold. Cell management requires thermal cutoffs for this reason.
My bike is 2004 Specialized mountain bike. Bought the motor from ebay and just bolted it on. The battery lives in a home sewn bag I made which I velcro strapped to the frame. I have gone about 35mph on it. Do not recommend super high speeds unless you are a capable bike rider.
It looks like a mad max experiment. I just wanted to ride the thing and wire management is def an afterthought. I do not ride anywhere I can't take it inside with me even though I only have about $500 into it. Too much work to risk theft.
So much fun to ride. Peeling out in dirt is thrilling on bicycle.