Interfacing Orion 2 with Thunderstruck EVCC [SOLVED]

[ekohn04]

Hey everyone,

I bought a TSM2500 with an EVCC from Thunderstruck a little bit ago, before I knew I was going to be using an Orion 2 BMS for my build. I want to let the EVCC handle the J1772 control and charge tapering because the Orion BMS I have is a limited functionality version from an Actia battery pack, I really just want it to report cell voltages and balance the pack.

The issue I'm having is getting the EVCC to accept CAN communication from the BMS. Even with the EVCC selected through the CAN section on the Orion utility, the EVCC keeps giving me a "receive timeout" when regarding the BMS communication. I was wondering if anyone with experience using this setup could chime in on what I might be doing wrong here. Thanks so much as always.

[tom91]

You check what speed the CAN is configured for and that you have configured it for the right bus?

Can the EVCC show you the raw CAN it recieves?

[ekohn04]

Yes, one of the limited features of the BMS I’m using is that it only has one CAN bus. I can see the CAN data in the EVCC terminal but it labels the messages as “unknown.”

[E46Driver]

I have an original Orion with older firmware that did not support full EVCC CAN. So perhaps you are facing a similar problem. I eventually got mine working using the EVCC cell loop (as the "Charge enable"). Then set your voltages and current in the EVCC. So with my setup, the EVCC controls everything and reaches the CC/CV setting I input. The Orion only controls the relay for the cell loop. This way, in case anything strange is detected by my Orion, it can shut down charging. Just be sure to use relays on the Orion analog signals, as they have very limited driving ability (I think my version only supports 250mA or something very small).

General operation:
1. 12V power turns on the modules (I have a switched 12V for this)
2. Orion boots and closes "Charge enable" relay
3. EVCC waits for cell loop to close (relay above)
4. EVCC then communicates with EVSE and begins charging (controls proximity and reads pilot)
5. EVCC then adjusts charge rate based on EVSE pilot and your settings

[ekohn04]

This is very helpful, I might run my setup like this. In this configuration, does the BMS just interrupt the loop when the pack is at full voltage since the EVCC isn’t receiving information through CAN?

[E46Driver]

Yes, the BMS can interrupt the loop. But thats just an emergency situation.

What I did was run multiple charge and balance cycles to determine my max pack voltage based on the max voltage of my weakest cell. The Orion will tell you this in the cell monitoring page. Once I was happy with the cell balance, I set my EVCC voltage just under the voltage where my weakest cell hits its maximum. This way, the EVCC always controls everything. And the CC/CV part of the charge cycle is always just under the max voltage of the weakest cell. It takes some time, patience, testing, and adjustment. The EVCC will never measure exactly the same as the Orion, but you can set the voltage accordingly. Once you establish that point, everything should work good. And the most important thing is the BMS can always kill the charge cycle if it deems necessary.

I've been running this setup for about a year, and its been good so far. In fact, a few months back, I noticed my cell balance was improved - and my max charge voltage could be increased by a few points. So over time, the Orion is able to bring the cells very, very close. I think my latest number was a variance of 0.103V over an 86s pack right before reaching full charge. Once settled, the cells are virtually identical across the board. And my pack has been in use off-and-on for 8 years!

[ekohn04]

Awesome, I've decided to run my setup like this. I couldn't get the "charge enable" or "charge safety" features to work on the Orion which is strange, it looks like Actia was using the "charge enable." I have the multipurpose enable function set to float high if any cell goes above a certain voltage, temperature, or if the Orion detects a wide variety of errors. The EVCC also has an option on the loop function called loopground, which allows for charging if the loop2 input is grounded. This lets me hookup the multipurpose enable pin on the Orion directly to the EVCC. I'm happy with this setup as I get the important features from the BMS and let the EVCC do the rest. Thanks for your help!

By the way, if anyone is interested I got this BMS off eBay for $500. Very good price for a BMS of this functionality.

[E46Driver]

Glad you got it working! That is a great price or an Orion - even with limited functionality. The EVCC and Orion work well together with this kind of "basic" setup.