CAN enabled Battery pack?

67BGTEV

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Anyone built a battery pack with CAN protocol to interact with production Hybrid Inverters like Sunny Boy Storage or StorEge ? Are there any DIY threads? I could find any in the search.
 

toms

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Plenty of BMS available for this:

REC
Batrium
Orion
Zeva
Emus

I’m sure there are others.

edit: do you mean instead of, or alongside the manufacturer storage?
 

67BGTEV

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Instead of buying a storage, I want to build one which has the capability to interact with the Inverter to provide oack state, Lowest, Highest voltage cell in a pack etc..
 

schroederjd

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I’ve read that the REC BMS’s CAN protocol is nearly identical to that of the Pylontech batteries, and most all-in-one inverters seem to be able to communicate with Pylontechs. That said, I’m not sure if ‘nearly identical’ is good enough when it comes to CANBus...
 

schroederjd

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I'm considering trying to use an ESP32 to 'emulate' the Pylontech CAN bus protocol. The concept being to use the ESP32 as a 'middle-man' between my TinyBMS and my Growatt inverter/chargers. I've already got the ESP32 pulling all data from the BMS via UART. Now i'm trying to figure out how to transmit that info to the inverters using a CAN module.

Do you have any coding and/or microcontroller experience? Or are you mainly looking for an 'off the shelf' solution on this? I'm pretty new at all this, so I could definitely use some help on the CAN bus emulator. Any others interested in collaborating on this? I think anyone using a DIYBMS could also employ this approach.
 

Luthj

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You probably just want a CAN-CAN bridge. Then just write the necessary code to translate CANbus frames between the two networks.

This arduino based unit is a good starting point. It has two canbus transceivers, and has a decent canbus library already written by the seller. I have used this unit successfully to intercept and modify CANbus traffic on some vehicle projects. You need to know some C/C++, but there are lots of good libraries for the Arduino IDE. The Due has some quirks, but its pretty straightforward.


 

schroederjd

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Thanks for the recommendation. That said, I’m now a bit unclear on exactly how these Growatt inverts communicate with BMS’s.
The Growatt Manual indicates that "there are four RS485 protocols in the inverter" for lithium battery communication. Based on the Pylontech documentation, there seems to be two communication protocols, one for CANBUS and one for standard asynchronous serial communication.

I had assumed that the the Growatt inverters used a CANBUS protocol, but maybe it’s just asycronous serial?
 

67BGTEV

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Though I don't have experience in Arduino or RPi, I'm willing to jump on it and work on it together.
 

schroederjd

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Sorry for the long delay on this. I'm considering a change of course on my battery management system. I'm pretty frustrated with the support I'm getting from Energus (the maker of TinyBMS), and I'm also not sure if 150mA balancing is going to be enough for my pack, considering the quality of the cells. I'm thinking about moving to a "semi-DIY" BMS. That is, use a 'smart' active balancer (eg JK-B2A24S CAN BUS) for cell balancing and cell voltage monitoring, then use a microcontroller (eg, ESP32) and external relays for all the protection features. In this way, I get up to 2A of balancing current along with the total flexibility of a MCU-controlled system.

JKBMS offers both CAN bus and RS485 versions of the active balancers. Obviously, these are unlikely to interface directly with an inverter, but the MCU should be able to act as a middle man.
 

67BGTEV

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I like approach and would be willing to explore this route. Where did you buy those? directly or AliExprs?
 

schroederjd

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I like approach and would be willing to explore this route. Where did you buy those? directly or AliExprs?
I haven't purchased yet. I've contacted three different suppliers: Heltec directly and two different Ebay sellers. The Ebay sellers only have the 24s versions, while Heltec has a 16s version. I'm waiting for final pricing from Heltec and if its reasonable (and shipping times are reasonable), I'll probably go through them.

Have you settled on an inverter? I want to be clear that I have no experience with CAN bus, so no guarantees that the route I'm taking will get you to a point that your inverter will talk to your BMS.
 

mnm1501

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Anyone built a battery pack with CAN protocol to interact with production Hybrid Inverters like Sunny Boy Storage or StorEge ? Are there any DIY threads? I could find any in the search.
Hi,
Could you port it from this?
Looks promising, I am trying to do something similar, I have a Growatt SPH5000 with several large batteries (27kWh total). Hoping to read info from batts sum it & send via CANBUS to the inverter.
Matt
 

tweekzilla

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Jun 23, 2021
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Jumping in here. I'm trying to integrate a batrium with a growatt SPF 12000T DVM over canbus. I read that you need to set the setting to L52 to use canbus although I'm not sure mine has that. Does anyone have the protocol docs for either the pylontec RS-485 protocol or what growatt is expecting to see either over RS-485 or can?
 
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