[metallica]

Originally Posted by thingstodo

Hi! Welcome to the forum!

I don't recall a BMS that Paul has designed. He has designed a 500Amp DC controller, a 1200Amp DC Controller, a 1000Amp AC Controller, a Resolver to Encoder converter board, and a DC/DC converter board .. that I know of.

I would suggest using a BMS that has a good track record, of course. The Leaf BMS is good at monitoring from what I read. I have not heard much about the balancing for the Leaf BMS. The Tesla BMS also has a good track record.

Are you recycling surplus batteries? Or building your own? For your first build I would suggest recycling. It simplifies things and you get results a bit quicker ... if you have the room in your vehicle for pre-built packs.

To talk to the boards in each Leaf module, Woltronix has a 'Leaf Pack sniffer 2' that I have read good things about.

For Tesla modules, EVTV has a board that will talk, as master, to the BMS in each Tesla pack.

Those are the most cost effective solutions that I know about.

I don't use a BMS - I bottom balanced my LiFePO4 pack and manually check the cells every 6 months or so, when I've run the pack low. The recycled cells have been rock solid.

My Leaf cells ... I foolishly damaged the boards while taking the pack apart. So I don't have an operable harness or the monitoring portions ... I check them about once a month. The controller on my Polaris Ranger EV won't start up below 42V. That's about 3V per cell. I didn't bottom balance the pack, I top balanced it so that all of the cells hit 4.1V at about the same time.
The voltage on the pack is not as stiff as the LiFePO4 cells, so when the Polaris shuts down, the cell voltage bounces back to about 45V. None of the cells is below 3V when I have let them cool down, before putting them on the charger.

But I'm just a hobbyist. I don't have a highway-capable vehicle running

Disclaimer: I am not affiliated anyone mentioned:
- Paul and Sabrina, I am a happy long-time customer
- Woltronix, I watch and enjoy his videos but have never purchased anything from him
- EVTV, I went to EVCON one year, and am a satisfied, long-term customer

Hi everybody,

Thank you for your answers to my question Thingstodo and Freebeard. And sorry to delay responding. I have had a quite busy schedule this week and in addition I lost the answer I gave you 3 days ago on the website...

So... in fact I used a wrong term when I talked about "BMS". It was actually the "AC Contoler" I wanted to talk about... It must be believed that I had the BMS in mind when I wrote my post, and I mixed the terms...

Anyway, I read the information from EVTV you mentionned. I found these reflections on load balancing issues interesting, and I will keep these issues in mind when I have to choose a solution for my future system.

I'm studying how I could achieve a vehicle retrofit from gasoline to electricity. I would like to start this project in a few months (begin of 2020). For now, I try to identify all the necessary components and associated prices, and get an idea of ​​the total cost of the operation.

Regarding the motor, I envisage to use a three-phase asynchronous AC motor, with a nominal power of about 25 KW, with the possibility of overloading it for a few minutes at maybe 35 KW or a little more.

In this respect, the Paul & Sabrina's AC controller should be a good choice. So I am looking for the plans and diagrams of this controller, as well as the complete BOM. I also thought, derive a less powerful version, so less expensive, since an intensity of 250A would seem to be enough for my project

Can you tell me where I can get this information? Having never realized this kind of transformation, I would also be very interested in any advice or additional remark.