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Laptop Powered E-Bike
Still waiting for fuse wire and 22 gauge (0.64 mm) wire, but I've started to put some cells together anyway. The first battery will be mostly red and blue cells, arranged with help from the Pack Builder, but also by color to give me a visual aid as to how they are oriented. It will be in a 3x14 grid and wired up as 7s6p. Here's the actual cells I'll be using. No dummy cell mock-up this time!

I plan to fuse the positives but not the negatives, and I think I'm going to wire it up in this configuration:
[Image: 85fde994a690001af7250b55fa90873f.jpg]
Though I could also wire it up this way.
[Image: 50b99c60590ebde218b8fbc3c5519fa7.jpg]
-Mike G
2nd one is better since you got "2" wires instead of "1"
And the first one is not even in terms of length between cells and can cause balance issues and you will stress the one closest a bit more than the one last in chain.

The first one would work better if you use an O instead of U format. And instead of L in the end use same as you have on pack 2
Jesse Osborn likes this post
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YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 100kWh LiFePo4 | 20kWh 14s 18650 |  66*260W Poly | ABB S3 and S5 Trip breakers
Upcoming: 14S 18650~30kWh
what motor controller do you have with it? can you limit AMPs? When I started building my bike I limited to 10amps so I could run 14s4p battery to start while I collected and built my other batteries. you could do some testing and maybe you won't need such a big battery. I'm also using a 7201a charger to charge (not balance charge though) my bike. and a RC charger to balance every once in a while.

you'll probably start to find a big bank problematic and will want to get power cells. I've gone almost 2000km's and looking at power cells so I can run a 14s5p setup.
I would be more worried about amp draw and what cells you used.

I used sanyo heaters on the kids power wheel battery and it gets HOT, you can hold it but its HOT.
So I'm capacity testing more battery's now and just going to triple the capacity.
(09-16-2017, 02:53 AM)Jeremy Choy Wrote: what motor controller do you have with it? can you limit AMPs?
I'll be using the Smart Pie 4 with the built in controller. I think the Amps can be limited through an app, but I don't remember.

Started wiring the first eBike battery today.

I started with the other configuration with the multiple wires, but in practice, they seemed too close together and I was worried about shorts. My first attempt at attaching fuses was a bit clumsy.

I had started out with the fuses soldered to the cells, then tried to attach them to the bus wire. My next attempt I did the opposite. I added the fuses to the bus wire first, then soldered the other end to the cells. I also staggered the fuses so they wouldn't be right on top of each cell, but to the side a little. This made attaching them to the cells much easier.

For the negative, I'm using 22g bare copper. Not meant to be a fuse wire, just a conductor. But thin enough that very little heat is needed to solder it to the cells. Here's the first side finished:

The fuses I'm using are 2A glass which AveRageJoe tested at 4 amps. Hopefully, this will allow me to use and charge the battery without blowing them, but also protect each cell from a dead short. They definitely protect against shorts. I've already blown 4 of them just by accidentally brushing the 22g wire against the positive of one of the adjacent cells. At some point I intend to test them myself, but I'm still waiting on parts to build a proper tester.

So the whole battery is wired up. I still have details like shrinking the shrink wrap and adding balancing wires, but for now, I get 26.5V on the multimeter. Near perfect as they were all around 3.8V when I started.
mormor1971 likes this post
-Mike G
Battery #2 is all soldered up!

I've got more ready, but I'm waiting on fuses. They're super cheap, but it takes a long time to get the order delivered. Now that I know I like them and will use them, I've ordered another 300. More than enough to finish this project.
-Mike G
More goodies in the mail!

More solder, 300 more 2A glass fuses, and some tiny heat sinks which I might use in my DIY balance charger. Those heat sinks are the smallest I could find, and they're still 4x bigger than the TP4056 chips I want to help cool.

I'm thinking I'll (very carefully) cut them in half so each piece will fit between the two capacitors without touching them, and glue the heat sink on with thermal glue. I wouldn't normally worry about heat from these guys, but I plan to have a lot of them inside a box, and I'm concerned that the cumulative heat might be an issue.

I've been corresponding with the folks over at, about the other components I'll need on my bike. I've learned quite a bit, and have gotten some good advice. So there's this dashboard accessory called the Cycle Analyst which not only shows tons of info about the motor and battery, but also adds a level of "smartness" and programmability to a compatible controller. So I'm definitely getting those two things from They also have reasonably priced throttles and "ebrake" levers too.

Unfortunately, I'm not sold on their motors. The selection they have is very small and very expensive. I'm not sure any of them will work for what I want. I may still go with a motor from Golden Motors, but I'll have to contact them to see if they will sell me a motor already laced into a rim. I don't see why they wouldn't, but their website only lists full kits or bare motors. There is also a motor I'm considering from AliExpress, called an MXUS FX39. From what I've seen on YouTube, this brand seems popular in Russia. 

Here's a rough idea of the layout I'm thinking of as far as where all this stuff will be going.
mormor1971 likes this post
-Mike G
Slow progress on the eBike, but its still going.

The bicycle got a proper fitting rear rack installed. And a third battery got soldered together yesterday:

Check out those solders. I'm getting better!

I've also been considering the other components I'll need. Here's my list as of today:
 - Controller: C4825-GR_STOKE
 - Computer: CA3-DP
 - eBrake levers: EBRAKEWUXD_SILVER
 - Throttle: T-TWIST
 - Hub motor: MXUS XF39 XF40

Still collecting parts to build the 14s balance charger. Not sure yet what its shape or size or weight will be. I'd like to have it mounted on the bike somewhere so its an easy plugin wherever. That will be determined later. And I'd still like to make the housings out of the old laptop battery shells. Haven't started that yet.
-Mike G
Hi Mike, some interesting ideas. Is there any update on your plans?
Sadly, no. I'm still trying to save up for the wheel/motor. Too many financial setbacks lately. The project is not dead though. Just waiting...
-Mike G

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