Giant DH team with Headway lifepo4

[hungarianguy]

Hellooooo!

After a lot of reading and dreaming I have started to buy some stuff to build something better than my first attempt:

Yes, it is 72V SLA, more than 60 km/h ! I loved it but it felt a bit dangerous and after two years the battery started to weaken.

So this will be the new one:
View attachment 2

Bought some used 10Ah Headway cells:


For now I will use my 1kW motor (9c clone?) with my cheap 72V 23A controller:

This is what I have so far.

And here is my to do list:

- situate and fix the battery cells
- connect the cells (get copper plate for it and cut it)
- lot of wiring
- figure out charging / protection
- make a torque arm

I should NOT write about it right now, but work on my thesis and study for my exams... I don't now how will it progress, probably slowly

*Sorry for my English!

 

[hungarianguy]

Let's start with the battery:

I am planning to use a 24s2p pack. I hope I can place 36 cells in the triangle:


and put the rest of the 12 cells next to the upper and lower tubes. The total width will be around 15cm, so I hope I can tighten the remaining 12 cells to the tubes of the frame (2x3 down and 2x2 up). Something like this:

I could get a box of aluminium welded in the middle. What do You think?
But I have no idea how could I get the cells fixed in the box.

The other topical question is the charger. I can't decide between rc charger + low voltage alarm and BMS + charer.

For now the rc charger (imax B6) seems better because with it I wouldn't have to charge the cells to 100% all the time and it also a bit cheaper. I don't want to buy a new battery pack for a few years, so the adjustable charging voltage might be handful.

But the BMS would be easier to use...

Anyways the cells are used, bought them from the ES's online market. These are 3 years old, have less than 100 cycles. The seller tested them with 10A and measured 9,2Ah and Impedance: < 6mΩ.

I don't have the tools to test them but a electrical engineer friend of mine will help me out with this 8) .

Let me know If You have any opinion about charger / protection.

I'm going to speak with the welder I know about the triangle.