Building a "new" ebike out of an old one.

[RebelRider.Mike]

Hi all. I've been tinkering with a home-made ebike for a while, and it's not gotten anywhere in the last couple years. Today I picked up a used one that someone made from a kit.


The previous owner knew nothing about it, but for the price he was asking, I couldn't pass it up. Turns out its a 48V 1000W motor powered by 4 12V lead acid batteries.


Not sure what brand. There doesn't seem to be a company name anywhere. There's only one marking on the controller.


The frame is too tall for me, so I plan to move everything to a smaller frame, and maybe replace the batteries with lithium. For now though, I'm pretty jazzed that it works and it's mine!

 

[fill]

Have fun with both the build and the finished bike.

 

[99t4]

maybe replace the batteries with lithium

The benefits will be massive! Lower weight, smaller size, more power and range, greater longevity.

 

[RebelRider.Mike]

I will be able to swap the front wheel over! Today I worked on getting the axle to fit the fork. Mostly working on spacers. I also got the front fender to fit on the smaller frame. Since I'm working on bicycles, I pulled out another old bike so I can fix it up and give it to my brother in law. The rear axle and bearings on that one are loose for some reason, and full of dirt. So that's getting cleaned out and re-greased. Waiting on a freewheel removal tool though.

Last week my basement looked like a lawnmower shop. Today it looks like a bike shop, LOL.

 

[RebelRider.Mike]

The bikes are now back on their feet after much fiddling and tinkering. The spare green one is finished and ready to go to my brother in law.

 

[RebelRider.Mike]

Latest video:

I have a whole series of other videos trying to build an ebike, but this is the first one featuring V3: the one that actually works.

Also, I got the bike together enough for a test ride around the block! It did pretty well, so back to tinkering. I built the battery 6 years ago. Today it got it's first charge:


Now that the bike actually works, I'll have to get a proper charger.

 

[99t4]

I built the battery 6 years ago.

No chronological degradation?

 

[RebelRider.Mike]

I'm sure some degradation is inevitable. I'm just impressed with it's ability to hold a charge that long. And with a BMS attached the whole time too. I have a LiPO4 battery that self-discharges way faster (still over 2 years) with nothing attached at all. It will be interesting to see what the capacity is now.

 

[RebelRider.Mike]

Today was bike day! Family and I went on a pretty flat 11 mile ride.


The ebike did great! I did a bunch of estimating, and figure I got roughly 0.64 of a mile per 1% of battery. So I might have a range of maybe 138 miles per charge. Based on a single flat ride, that's probably not accurate, but it's at least a ball-park figure to work with for now.

Nothing fell off. Nothing got hot. And for once I wasn't the slowest person in the group!

Lots more to work on since this is still just the prototype, but this was a fun day!

 

[ZeroEm]

Riding Ebikes are great fun, enjoy!