Help with BMS for Chevy Volt / Opel Ampera 1st gen battery

Hello everyone.

After weeks searching for the best BMS for a Opel Ampera/Chevrolet Volt 1st generation battery pack (reconfigured to 44 V nominal voltage: 12S8P, 16 kWh) I am a little bit lost about what choice would be the best.
I have been using this battery for a few weeks and the balance is with 0,01. Very good. There are people on Internet who after one or two years they still have that balance. So, in theory, I would not need a very strong balance power.
I read a lot of threads (here and another forums) but I could not find a definitely solution (Only the a guy with 4 Chinese Smart BMS told he was fine with that setup) so I ask if someone here have experience with this.

Here are the more interesting:


SimpBMS:
It can handle the OEM slave BMSs of the battery banks. That sounds pretty good.
Integration with Victron (my charger/inverter)

The worst part:
Not so easy to mount, and not a lot of info (at least with my battery)
Cant get data from other systems, and no graphical interface.
Cant add more slaves, if I buy another pack, I need another SimpBMS.

Price: +-350 EURO



Batrium Watchmoon 5:
I wanted to go with WM4 + Longmons but after speak with Batrium support they told me what with me battery type it would not work fine. So I would have to go with WM5. But I dont like the idea of parallel the series. I only have 96 cells in my system.

Price: +-600 EURO




Chinese Smart BMS:
Already have one at home, but I didnt use it. I have seen people who use one for each two pararells (total 4 BMS) and happy with them. Other option would be have one for each parallel.
There are a project (from a user of this forum) to get data from it (I dont know if it possible handle 5 or 8 BMS), that would make more interesting this option.

Price: +-60 EURO for each.



DIYBMS:
I have to make more research, but look I dont have enough time for this right now. But looks very good.

And other systems like Chargery....



What do you think guys?


Thank you in advance.

I can only speak to the wm4/5 debate - you can't use wm4 with a shared loom with out issues so that's out. WM5 would add a bunch of neat features (if ou needed them) but adding more packs would require the MiniMon8 (MM8) for each new battery.

A BMS is basically this in this order:

1. Critical fault protection unit
2. Notification on eventual issues and status
3. Capable of balancing.

The first 2 are the most important and balancing is what will make the battetery last a long time. You can go with lover balancing current but just DONT hide it with those cheap balancers. Its better to not have any balancer than hiding it in my world.

Whats important is that you get a unit that can disconnect the system if needed and that can inform you if so happened or will happen.

I vote for Batrium to and shared look require WM5.
With that said the others will work to.

hbpowerwall said:

I can only speak to the wm4/5 debate - you can't use wm4 with a shared loom with out issues so that's out. WM5 would add a bunch of neat features (if ou needed them) but adding more packs would require the MiniMon8 (MM8) for each new battery.

Click to expand...

daromer said:

A BMS is basically this in this order:

1. Critical fault protection unit
2. Notification on eventual issues and status
3. Capable of balancing.

The first 2 are the most important and balancing is what will make the battetery last a long time. You can go with lover balancing current but just DONT hide it with those cheap balancers. Its better to not have any balancer than hiding it in my world.

Whats important is that you get a unit that can disconnect the system if needed and that can inform you if so happened or will happen.

I vote for Batrium to and shared look require WM5.
With that said the others will work to.

Click to expand...

Thank you both very much for your answers. And for your videos, they are very helpful.
It suppose that this batteries don't need to be balanced very often, but I want to monitor and check themall the time. It deserves it just for the tranquility.


I was thinking about go with Batrium, but if I understand well I would need one WM5 and seven MiniMon8.

Here is the wiring diagram:





And I have 8 batteries (with shared loom) with eight negatives and eight positives (plus 8balancing sockets, connected toeach cell). All positives are connected together in a bus bar (same for negatives):







I can't get how would be the right way do connect a singleWatchmon 5 to this battery, if it is possible. I asked the Batrium and they submitted this wiring diagram. Still lost.



I am really happy with this battery, but is a pity I can't use WM4




Thank you again.

Hi,
Im setting up a similar project and want to find a BMS that works as well. Would you mid sharing your setup with me? are you running the Volt cells in 12s or 14s? Have you had any issues with low voltage cutoff?
Thanks, Jerry

engarom said:

Hi,
Im setting up a similar project and want to find a BMS that works as well. Would you mid sharing your setup with me? are you running the Volt cells in 12s or 14s? Have you had any issues with low voltage cutoff?
Thanks, Jerry

Click to expand...

Hello,
Sorry for the late reply.

I haven't solve this problem yet. At the momento I am manually checking the cells, but I have a work in progress system:

I have 2 Chinese "BMS Smart" connected to 2 of the 8 modules (My configuration is the original 12S) and a Raspberry Pi, reading the batteries using this software:https://github.com/simat/BatteryMonitor
And from Home Assistant read the values, and then I can control de Victron inverter to stop charging, or whatever. I would like to add a external circuit breaker too.


I want to order 6 more BMS, to can control every module. I don't want to parallel cells. My doubt if it would be good to balance every module independently (now I only monitor, no manage them)


Regards.

Rober said:

Batrium Watchmoon 5:
I wanted to go with WM4 + Longmons but after speak with Batrium support they told me what with me battery type it would not work fine. So I would have to go with WM5. But I dont like the idea of parallel the series. I only have 96 cells in my system.

Price: +-600 EURO

Click to expand...

As a WM4 + 70 longmon(s) user of Batrium - I didn't get (out of the thread)why WM4 + Longmon won't work in your situation. Is it because you don't have wiring (access) to individual cells? Could you explain more? I'm just interested

Rober said:

Hello,
Sorry for the late reply.

I haven't solve this problem yet. At the momento I am manually checking the cells, but I have a work in progress system:

I have 2 Chinese "BMS Smart" connected to 2 of the 8 modules (My configuration is the original 12S) and a Raspberry Pi, reading the batteries using this software:https://github.com/simat/BatteryMonitor
And from Home Assistant read the values, and then I can control de Victron inverter to stop charging, or whatever. I would like to add a external circuit breaker too.


I want to order 6 more BMS, to can control every module. I don't want to parallel cells. My doubt if it would be good to balance every module independently (now I only monitor, no manage them)


Regards.

Click to expand...

Hi - Were you able to get your system with the 2 Chinese "BMS Smart" setup? I have a similar situation and would be interested in your feedback on how well it is working for you. Thanks!