Blog / Battery cells and BMS connected
It's time for another new update.
The past few days I've been busy connecting all of the battery cells to eachother. It all went well, for extra safety I already isolated all of the tools with some tape. For the rest you just have to stay very focused.
But that's not all yet, I also started on the BMS (Battery Management System).
First I made all of the wires exactly to size.
Then I connected them all to the battery cells and to eachother. Thought it'd be a lot of work but it wasn't all that bad. It was the first time something actually took less time than I expected, usually it always takes longer. They're also connected inbetween the battery boxes, this was actually the hardest since at one part I had to push 4 wires through that wire loom. The size I used actually is for only 3 wires. But it all went fine anyway.
Looks pretty nice too. The green LED's show that they're connected properly and that the battery cell is at the right level.
In the dark it also looks nice with all of those LED's. Just too bad that you won't see any of it anymore once the battery boxes are closed.
I also connected the throttle now. I used 2 resistors for this and one extra wire, these are again for the BMS. These will make sure that there's not much power available anymore once the battery cells drop below a certain level. This way you won't immediately destroy the battery cells while still being able to get off the road safely.
Also placed all of the fuses to be able to test the 12V system. Meanwhile I've already broken one and replaced it, apparently the contactors needed a little more power.
And I can already say that the 12V system is working perfectly. I just had to make a small modification with a relais, for the rest everything seems to be fine. I just have a weird problem where the controller sometimes doesn't give any power the motor after I let it run in reverse and then forward again. Could be that there's just not enough voltage since everything was connected to a 12V battery. Just have to connect the wires to the controller again and then I can try with almost 80V, see if it works better then.