BMS recommendation 4S4P communicate with Victron

[acolunga07]

I am building my first battery and struggling with deciding which BMS to get. I had convinced myself that JK was the way to go but I’ve read many threads on here about various issues people have had with their JK.

I am building a 4S4P pack with CATL 280 Ah cells. Currently planning to get 4 BMS’s (one for each string). I could possibly be talked into doing a 4P4S configuration with a single BMS but prefer the 4S4P config so that I can see each cell.

They will be powering my travel trailer via a Victron multiplus 3000 and I really want the BMS/invertor to talk each other. Since I will have 4 packs, I should only need a 120-150A BMS (my invertor can only pull 3000 watts) right? I am not sure

 

[acolunga07]

The last part of my post got cut off:

I am not sure how Louis’s driver will handle/treat 4 BMS but hopefully it’ll be in a way that makes sense (as seen on the Cerbo GX). It seems active balancing and low temp cutoff are good features to have.

Anything else I’m missing?

For reference, this is what I am planning to do:

Camper Wiring Diagram w/ 3000w Inverter & 600-1200w Solar

3000w Inverter, 600-1200w Solar, Battery to Battery Charger, Shore Power, 600Ah Lithium Batteries

www.explorist.life

 

[toms]

I would use REC ABMS with 4P4S battery configuration.

 

[acolunga07]

Thanks for the recommendation toms. I sent an email to REC to make a specific product recommendation. I’ll wait and see what they respond with.

From the research I did on the product, would it make sense to use their shunt and have the REC BMS report SOC to Victron or use the Victron smart shunt?

 

[toms]

I would just use the REC shunt. Leave the BMS in control of the Victron gear.

 

[acolunga07]

I would just use the REC shunt. Leave the BMS in control of the Victron gear.

You mean let the BMS manage all things battery related and let Victron do overall power management?

I didn’t get an overnight response from REC which seems reasonable but not what I expected (based on several peoples experience with them).

When you mentioned getting their 4S4P configuration, which product did you have in mind?

REC BMS – REC Battery Management System

www.rec-bms.com

It seems the active BMS can only handle 4 cells in series?

 

[toms]

Yes, i said 4P4S

 

[hwse]

I was one of those who had a failure on the 4s-8s JK. Mine was in the gen-1 units and was purchased about a week after they were released. My replacement JK was purchased last August and is working fine. I have been searching for failure of the newer units and have not found any reports since around the first of the year.
I really like the way the JK works.

 

[toms]

I was one of those who had a failure on the 4s-8s JK. Mine was in the gen-1 units and was purchased about a week after they were released. My replacement JK was purchased last August and is working fine. I have been searching for failure of the newer units and have not found any reports since around the first of the year.
I really like the way the JK works.

Yep, they work good until they fail - which happens too often.

 

[hwse]

Yep, they work good until they fail - which happens too often.

I am still interested in finding anyone who had had recent failures. So far, it seems that the main problem was with the first batch released because I have not heard of any recent failures.

 

[acolunga07]

Ah, I see the 4P4S recommendation in your original post. The REC active BMS recommendation makes sense now. It seems that rather than running the full current through the BMS as some do (and are limited by this), this product allows me to install my own battery switch and control that via the REC BMS. This does seem inherently safer (for the BMS to disconnect the battery as needed based on temps).

Any other specific reason to recommend the REC BMS?

 

[740GLE]

Any reason why you’re sticking to 12v system?

For that kind of storage 8S2P seems to be nice middle ground.

 

[hwse]

Any reason why you’re sticking to 12v system?

For that kind of storage 8S2P seems to be nice middle ground.

I do not know why others use 12v, but for me it is because I am using my LFP batteries in my sailboat and motorhome. Both of these vehicles are 12v systems and to put 24v or more into the mix would be expensive and increase the complexity.

 

[acolunga07]

Any reason why you’re sticking to 12v system?

For that kind of storage 8S2P seems to be nice middle ground.

I really struggled with this decision. My application is a travel trailer (21’ Micro Minnie 2100bh) that Im upgrading. Everything on there is already 12V and it is my first time doing something like this so I’m trying to reduce the chance of screwing something up.

 

[Rocketman]

For a 21’ travel trailer 16 280ah cells seems like a lot (to me). I have eight 272ah Lishen cells in my MotorHome along with the Multiplus 12/3000.

With my setup every night I use approx 25%. Then the solar refills (1400w). I don’t heat water, nor use the air conditioner much (I can for 1hr - then I need to turn on generator). But if you are using a smaller solar array, you may need a larger battery.

For my battery I did 2p4s and used a Batrium bms. It also uses an external contactor. Tyco EV200AAANA.

One of the original reasons for selecting Batrium is it would connect to Victron’s Can- bus. But after I got the battery setup, I have changed my mind an don’t have any communication between the bms and Victron. I think I like Victron’s charging profile better than the bms ones. ( but I could be wrong there).

Here is my journey:

Batrium Watchmon Install

Hello everyone, I have a 2000 Monaco MotorHome, I will be installing eight 272ah Lishen LiFePo4 cells making a 2p4s 12v 500Ah (useable) battery. My two largest loads are a Victron MultiPlus 12/3000 inverter/charger and the engine "Boost" if my chassis battery gets low. For the BMS I chose a...

diysolarforum.com

Good luck with your project!

 

[acolunga07]

For a 21’ travel trailer 16 280ah cells seems like a lot (to me). I have eight 272ah Lishen cells in my MotorHome along with the Multiplus 12/3000.

With my setup every night I use approx 25%. Then the solar refills (1400w). I don’t heat water, nor use the air conditioner much (I can for 1hr - then I need to turn on generator). But if you are using a smaller solar array, you may need a larger battery.

For my battery I did 2p4s and used a Batrium bms. It also uses an external contactor. Tyco EV200AAANA.

One of the original reasons for selecting Batrium is it would connect to Victron’s Can- bus. But after I got the battery setup, I have changed my mind an don’t have any communication between the bms and Victron. I think I like Victron’s charging profile better than the bms ones. ( but I could be wrong there).

Here is my journey:

Batrium Watchmon Install

Hello everyone, I have a 2000 Monaco MotorHome, I will be installing eight 272ah Lishen LiFePo4 cells making a 2p4s 12v 500Ah (useable) battery. My two largest loads are a Victron MultiPlus 12/3000 inverter/charger and the engine "Boost" if my chassis battery gets low. For the BMS I chose a...

diysolarforum.com

Good luck with your project!

Thank you for the very thoughtful response. The reason I am going with such a large battery pack is to be able to run the AC overnight without having to worry about the generator (at least for a night). We go to a lot of national parks, and I many do not allow generator use past a certain hour.

I was about to pull the trigger on the REC ABMS but I have heard of the Battrium spoken of equally as well. I’ll check it out tonight.

 

[toms]

Thank you for the very thoughtful response. The reason I am going with such a large battery pack is to be able to run the AC overnight without having to worry about the generator (at least for a night). We go to a lot of national parks, and I many do not allow generator use past a certain hour.

I was about to pull the trigger on the REC ABMS but I have heard of the Battrium spoken of equally as well. I’ll check it out tonight.

I currently use both Batrium and REC - for your system I would recommend REC.

Batrium advantage is flexibility, it comes at the expense of complexity.

 

[acolunga07]

Thanks again toms for the feedback and sharing of your experience. After looking into it, I agree. It does seem the batrium might be suited for larger/more complex packs. All signs point towards REC being the best option for me.