Reverse engineered SIMPbms now working on SMA Sunny Island series


Active member
Oct 21, 2017
Hello All,

I've been working on a new test rigg.
SMA Sunny Island LV DC inverter charger + Simpbms + GS YUASA LEV40N/50N cellblocks with CMU
I've reported earlier on the SIMP bmshere

The current firmware version of SIMPbms can adres 10 unique cmu ID. so max set-up =5S16P ~12Kwh LEV40N or 14Kwh LEV50N

SIMPbms is a shield with a Teensy 3.2 capable to work with/control various oem EV batteries and their cmu's, like Tesla BMW VAG (VW-Audi) Mercedes Benz GS YUASA Mitsubishi Outlander /iMIEV and clones from Peugeot/Citroen.

Porting this SIMPbms to brand name inverters is in slow progress.
First was the Victron range via Venus OS on the Venus GX, and the Color GX, as described earlier.
now we have the SMA Sunny Island series working

Next step will be giving it a try to go High Voltage, SMA Sunnyboy Storage series.
Hooking up a complete pack 400Vdc, controlled with a SIMPbmsto one of these:

If somebody from the forum has the can-protocol of this SunnyBoy Storage range, and is willing to share, please please do.

All work is on Github:

I will try to update this thread with additional info in coming month

best regards
Carel Hassink











New member
Mar 21, 2019

Any progress on the sunny boy storage? It would be VERY much cheaper then using Sunny islands. We can through my company get hold of the sunny boy 2.5 for 600gbp ex vat vs 2300 ex vat for the sunny island. 2x sunnyboy would be more than enough for me :) I will be building a 73kwh battery from 3 complete leaf packs + 3 modules. for BMS, the plan was to use REC, as it comunicates with sunny island directly through can-bus.


Active member
Oct 21, 2017

The SMA SBS range 3.7-6.0 has no parallel or 3-phase features
So single phase only in HV,

I have a complete test rig build up BYD batterybox 6.4Khw+SBS6.0,
it took me some time to save up the money to go for the next step buying a BYD batterybox.
Together with Daniel Boekel, we're sniffing out can messages, and beam these over to Tom de Bree, currentlybased in Bristol area.
Tom will try to decode and adapt to new firmware for the SIMPbms

It'll be some work to hack it, we're just after proof of concept, to go into next phase,
working with another guy from Norge, Even Tjorhom, wanting to hook up a BMW i3pack(s)
I'm interested in having an i-MIEV/outlander pack used.
The bigger inverters have 3 strings for battery, think max 36Kwh 3 strings of 12Kw full 320Vdc packs.

But read the manual before wishing for too much

Do consider that making the leaf cells work with HV may take a lot of cell monitors of whatever brand of commercially available bms, to get to about 200Vdc, best would be 300-400Vdc,
and still you need to make it talk to SMA SBS.

That's exactly the queeste we are on, using second lifebattery packs with integrated cmu, decode protocol, have SIMPbms act as mastercontrolling battery, + making SIMPbms integrate to various inverters/chargers etc, including these newer types of Hv models
More info on SIMPbms can be foundhere

We surely can use help of the community.

We are looking for:
Kostal Plenticore Plus+BYD owners,
Solax X-Hybrid 3phase owners

to help sniff can messages in between inverter and battery

with regards
Carel Hassink


New member
Jul 20, 2020
Hello Carel,

first of all, thank you very much for all the effort you put into this project and and to the community as a whole.
I stumbled across your posts in various forums now and found them always quite helpful.

Since I also got some battery laying around, that I'd like to use in combination with a SMA Sunny Boy Storage, I wonder if you got an update to this reverse engineering project?

In my case it's a used Leaf ZE1 40kWh battery which I'd like to connect to the inverter as ist comes and only translate the CAN information from Nissan protocol to SMA protocol with the help of some Raspberry Pi magic. Hence the amazingly well documented Nissan CAN protocol, the first half of this project is already up and running. I'm just lacking the SMA side of the translation.

I'd be happy to help anytime, just let me know how.

Best Regards,


New member
Dec 13, 2019
Did you ever post code for communicating with the SMA Sunny Island? Don't see it on your Github.