Zoe 52Kwh Battery Storage

[lawrence]

I wanted to share the project I've been working on recently, to set up home battery storage using a Renault Zoe 52kwh pack from a scrapped car.

The battery pack came from EV Breakers in Northern Ireland. The DC is connected to a FOX ESS H1 6kw high-voltage hybrid inverter via a MCB. The communications cable is connected to a Raspberry Pi based interface. This handle the can bus communications, the relays for 12v/precharge and the MOSFET to control the main contactor.

The Pi acts like a canbus bridge, communicating with the battery, and with the fox, so that they can talk to each other. It also handles Modbus to communicate with the inverter and the meters.

In the photos, you can also see a 12V battery backup power supply to maintain power to the control equipment in the case of a power failure so that the battery can still operate. There is also a small consumer unit for the essential power supply

This is only possible thanks to some code that woleg/rand12345 put on github showing the can bus protocol for both the Fox battery and the Zoe PH2 battery. Unfortunately it looks like that has since been removed, but there are some useful links I've pasted below

Fox Modbus:
https://github.com/StealthChesnut/HA-Fo ... usUSB.yaml
https://github.com/nathanmarlor/foxess_ ... ns.py#L180

Zoe canbus:
https://github.com/fesch/CanZE/blob/mas ... Fields.csv

[usus]

Hi,

Are you sending Modbus messages to the inverter?
Can you share the code?

[lawrence]

Yes I'm using Modbus for both Zoe and Inverter comms. My code is quiet specific to the environment I use, but it's based on wolegs CAN sniffing here https://github.com/rand12345/solax_can_bus

[usus]

I am ok on can side. running without problem.

But on the Modbus i don't have any registry description.

Being in Sweden i need to charge when the price is lowest may be in the middle of the day or the entire weekend.
For this i need to be able to tel inverter when to charge.
Second variant is to use CAN msg 0x1872-charge_max and set the inverters to charge all the time but I don't allow battery to be charge unless I want.

BR.
usus

[lawrence]

Ah sorry I got confused. I use CAN bus to talk to the Zoe and the Battery side of the inverter. Seperately Modbus to talk to the data side of the inverter. I've been controlling the charge from the CAN side, by setting the max charge amps to stop/start the charge. I only use the Modbus to read data from the inverter to check things are working.

I haven't yet implemented it, but I believe you can set the timed charge parameters via Modbus
https://github.com/StealthChesnut/HA-Fo ... usUSB.yaml
If you set Time 1 to for example 01:00 to 02:00, with enabled off. The battery will go into standby at 01:00 to 02:00 and your house will use cheap grid power. If you set enabled to on, your battery will force charge up to the max charge limit set on the inverter settings. So you have to set Time 1 to have the same start/stop time to fully disable it.

I haven't implemented any of this yet as during the summer there is so much solar I haven't needed to use our cheap grid time which for us is 00:30 to 04:30.

[usus]

I leave in Uk 2 years and is simple to import power. Plus in the north is no gas only electricity. in a month here i use like in a year in UK .

In nordic counties power is like the stock market and the pay for transport fees. For example tomorrow (12.07.23) the cheapest hour in SE3 it is between 13:00-14:00.
https://www.nordpoolgroup.com/en/Market ... view=table

I was thinking that is not the best solution to enable charging via CAN by max charge on the battery but for the moment i will go that way.

Still why do you use 3 converter for Modbus? Ca not be all on the same bus with different ID?

[lawrence]

Ah okay. I've been controlling charging via max_charge amps and it seems to work well, it's very quick to respond and can keep the battery at a specific charge level that way.

One modbus talks to Fox on the normal RS485, another is for my main Modbus network with multiple devices, and the other is on the Fox Meter Modbus. I intercept the fox meter modbus because if it's on the normal main modbus network, it wants to be the master. There can only be one master on Modbus so then I wouldn't be able to talk to anything else on the modbus network.

I could put the normal Fox RS485 on the main network, I just haven't tried it yet

[yasko]

I wanted to share the project I've been working on recently, to set up home battery storage using a Renault Zoe 52kwh pack from a scrapped car.

Nice project!
Do you have a pinout of the LV battery connector? I'm unsure whether it is the same as previous models (22 and 41kWh).
The picture looks the same, but can you confirm that signals also correspond?

I'm on the way to doing a similar project, but I'm still researching.

[lawrence]

The connector is the same 12 Pin 7282-8854-30 but the pinout is different, pinouts attached. These are from Renault "New Dialogys" which you can pay for, for just an hour, to get diagrams and pinouts. For the relays to work you'll need to connect that "HYBRID 3 Relayed" pin, but I can't remember if it needs -12 or +12v off the top of my head.

You can see canbus dumps from the HEV bus here https://github.com/ljames28/Zoe-PH2-EV- ... nformation . It only really needs to see 0x373 to wake up and then you can talk to it using https://github.com/fesch/CanZE/blob/mas ... Fields.csv

However, I've had the battery running since, and the delta between the minimum and maximum cell volages has been rising. It's now sitting around 120mv. There is at least one other person with the same issue. As far as we can tell, the battery is never balancing. Presumably there is some sort of signal or something on the canbus in a certain sequence that it is expecting to see. I've even dissambled most of the LBC controller code but haven't yet worked this out.

[lawrence]

I believe the balancing issue is now solved by sending accurate time information to the pack via the canbus. There is more information about all the LBC can frames here https://github.com/ljames28/Renault-Zoe ... nformation

[geamanug]

Hello. I am trying to sniff data out of a 27 kw Dacia Spring pack so I can complete integration with a Fronius hybrid inverter. So far I managed to build a data extension cable and also bought a can reader out of aliexpress in order to use it with busmaster or savvycan. I did some work with rs485 in the past but limited knowledge with can protocol. Any guidance would be greatly appreciated. New to this forum so please be kind with my mistakes.

[johu]

Hi, can you place the Dacia info into a new thread. Thanks!