openinverter forum

Thanks Arber333, this info on the fuses is very usefull.
I have reverse engineerd the cell balancing hardware. My finding are these:
The balancing is passive with resistors, starting from the negative, there is a 1 ohm resister inseries with 2 resistors of 8.2ohm a diode, a mosfet, then a 1 ohm resistor leading to the positive lead of the cell, so the total resistance is 1+8.2+8.2+diode+1= 18.4 ohm’ the max voltage for balancing is normaly 4.2V, this gives a current of (4.2-0.6)/18.2=197mA as a max balancing current.

Some photo’s of the balancing board:

Anyone been able to open the i-pace BMS communication? I ask this frequently in this forum at different makers because I am trying to build home ESS and I am on the market to locate most cost effective batteries.
For some reason I-pace and Polestar 2 batteries are at the moment in east europe the cheapest by big difference (like 40-50% compared to tesla or leaf when taking price and capacity in account). Reason probably is that the bms communication is not available so utilizing these are not so straight forward.

I'm in the same boat, having an i-pace battery (disassembled) for the ESS project. I want to reuse the BMS and start gathering information about it.
What I found so far:

* The configuration of the BMS is one master and six slave modules, and communication between them is CAN-based.
* Each slave module has two sections (seen in the pictures above). Each is based on TI 76PL455ATQ (cell monitoring) and NXP processor for communication. So there are 12 CAN nodes, each monitoring 9S cells (3 blocks x 3S)
* I have found schematics that give me some information for a starting point. I also identified most of the connector types used in the BMS.
* I have ordered some needed connectors for BMS hacking and will start experiments soon. I am still planning a strategy. It will probably be best to wire again the whole battery, but now I don't have enough space for that.

That's exciting, I was looking at buying one last year and spoke to Kutato and Tom91 on here about the IPace, it might be worth contacting them for information

You need to wire it all up and get a CAN bus capture of the information being sent "to" and "from" each slave for further analysis and decoding.

I agree that the best option is to restore the original wiring of the battery and then start analyzing.

But now, I have started exploring one of the slave modules, and the results are good so far.
It sends CAN data without any request, and I think the data contains the cell voltages and temperatures.
I need to recheck it, and I will share the result in the new topic.

yasko wrote: ↑Thu Jan 25, 2024 11:44 am I will share the result in the new topic.

Share any raw logs you have.

The biggest challenge will be balancing requests and other things that will get directed from the Master controller.

I notice an I-pace battery pack on ebay - 90kWh for less than £4000! very cheap per kWh!

SuperV8 wrote: ↑Tue Feb 06, 2024 2:29 pm I notice an I-pace battery pack on ebay - 90kWh for less than £4000! very cheap per kWh!

it's been up some time, I reckon you could knock it down further!