jerryki1234
New member
- Joined
- Jul 1, 2020
- Messages
- 13
Hello,
There's this bicycle in my garage... It's a "Charger". It belonged to my late son. After his second DUI, he needed something with no license requirements to make it up the hill to our house.
The bike dates from the mid 90's. It was pretty hot stuff for the time, with a 24V motor mounted in the frame driving the rear wheel via a chain. Said rear wheel has a 7-speed Shimano hub. The front forks have shock absorbers. The two 12V SLA ( lead acid ) batteries are in a plastic box, along with the control and charging electronics. The bike had no throttle - it would help you when you pedaled.
Said electronics are long dead. I thought to resurrect it - bought & installed a pair of brand new SLA batteries. Left them to charge overnight. Came out the next morning, and the whole garage smelled like battery crap. The batteries had swollen up like little balloons( sigh ).
So now I am embarked on a new project - to bring this bike up to date with a lithium ion battery pack. I got a boatload of 18650 cells from batteryhookup, and a fancy charger/tester that tells their capacity in milliamp-hours. A package of nickel strips. A "k-weld" spot welder. An old aircraft battery to power the k-weld. Need a box for the battery ( on order from Amazon ), because although it does deliver the current, it's not as liquid-tight as it once was, and when you pull great gobs of current out of it, it *spits*.
I had gotten a cheap Chinese welder board - IIRC $25 including probes - but it didn't work reliably. Basically, I would put approximately one zillion spots on each battery, and hope that enough of them "took" to have the strap stick on. Reading about the kweld, I just had to have it. Would have been cheaper to just buy a premade battery pack .
But now I'll be all set up for any battery projects that come around.
The original electronics package is large and heavy - with 2 SLA batteries, the charging circuitry ( you open a little door and pull out the line cord ). I think a pack of 18650's will be much lighter.
I don't know how much power the motor takes under load. Am hoping a 7S5P pack will be adequate. Or is it 5P7S? I bought a 20A BMS on Amazon. We'll see how it does.
There's this bicycle in my garage... It's a "Charger". It belonged to my late son. After his second DUI, he needed something with no license requirements to make it up the hill to our house.
The bike dates from the mid 90's. It was pretty hot stuff for the time, with a 24V motor mounted in the frame driving the rear wheel via a chain. Said rear wheel has a 7-speed Shimano hub. The front forks have shock absorbers. The two 12V SLA ( lead acid ) batteries are in a plastic box, along with the control and charging electronics. The bike had no throttle - it would help you when you pedaled.
Said electronics are long dead. I thought to resurrect it - bought & installed a pair of brand new SLA batteries. Left them to charge overnight. Came out the next morning, and the whole garage smelled like battery crap. The batteries had swollen up like little balloons( sigh ).
So now I am embarked on a new project - to bring this bike up to date with a lithium ion battery pack. I got a boatload of 18650 cells from batteryhookup, and a fancy charger/tester that tells their capacity in milliamp-hours. A package of nickel strips. A "k-weld" spot welder. An old aircraft battery to power the k-weld. Need a box for the battery ( on order from Amazon ), because although it does deliver the current, it's not as liquid-tight as it once was, and when you pull great gobs of current out of it, it *spits*.
I had gotten a cheap Chinese welder board - IIRC $25 including probes - but it didn't work reliably. Basically, I would put approximately one zillion spots on each battery, and hope that enough of them "took" to have the strap stick on. Reading about the kweld, I just had to have it. Would have been cheaper to just buy a premade battery pack .
But now I'll be all set up for any battery projects that come around.
The original electronics package is large and heavy - with 2 SLA batteries, the charging circuitry ( you open a little door and pull out the line cord ). I think a pack of 18650's will be much lighter.
I don't know how much power the motor takes under load. Am hoping a 7S5P pack will be adequate. Or is it 5P7S? I bought a 20A BMS on Amazon. We'll see how it does.