Help with BMS selection

[Rocketman]

I choose Batrium Watchmon4+expansion board for the following reasons:
1. Able to communicate on CAN-Bus with my Victron CCGX
2. Making changes to the bms was easy and understandable. (Setting voltages, setting critical aspects, etc.)
3. It used a contractor so I could use my lithium RV battery to “boost” my chassis battery to emergency start my diesel RV. Needed a very high current- (estimated 500 to 1000 amps at 12v).
4. Wanted battery heating, cooling options with simple relays that I can understand.
5. I wanted controls to shut down battery gracefully and predictable when going into critical state (low voltage)
6. I like information- wanted to easily see status of battery.

Those are the reasons I choose Batrium. It seemed to completely fit my needs/wants/desires for a bms. They shipped very fast - about a week. (Batteries unfortunately don’t ship in a week - mine are in a container somewhere in China). (I haven’t installed it yet - that’s project is early spring).

For the contractor I choose Kilovac EV200AAANA - there is also others.

 

[lance]

I struggle so hard with trying to sift through these answers and see how/if they apply to my situation. That's not a dis on your answer! It is just so much that I don't know, and my goal here is to learn what I need to learn but, this is never going to be a hobby for me. I want to build an excellent quality system, robust enough to handle potential expansion of needs but, also robust enough that even with current known/anticipated needs isn't running near the top of it's capacity frequently if ever.

Contactors are just heavy duty relays that are designed to be on most of the time and can interrupt large DC loads. I have used Tyco Contactors because I am familiar with them from converting a VW to an EV. Solid State Relays can also be used. That is the only choice for me because my Inverter does not have an external switch.

So, is this something that would be relevant to a standard system in a camping vehicle? I anticipate a 3000w inverter running potentially a H20 heater, an oven, and an iMac as it's biggest 110v draws. The fridge/freezer will be 24v if I can afford the unit I want. I don't think any of this touches the needs of an EV.

If your inverter has a switch then wiring one of those interfaces to turn of the inverter would be much simpler.

So, essentially this contactor is essentially acting as a switch to shut off the inverter in the case of a malfunction? A circuit breaker of sorts?

That kind of communication can be found between some BMSs and Inverters and one that I was hoping for in my installation. Orion has one with Schneider and Victron and REC may have one with another Inverter. I think Batrium may also. As I mentioned earlier that interface is how I would decide on a BMS and/or and Inverter/charger.

I currently have the Victron MultiPlus 24/3000/70-50 VE.Bus Inverter Charger on my wish list for inverter/charger. In reading through the specs on it now, I'm not finding anything that seems to relate to interfacing with a BMS

I would be happy to elaborate or answer any other questions.

Thank you!

 

[lance]

1. Able to communicate on CAN-Bus with my Victron CCGX

So, the CCGX is essentially a communication/information module that sits between your inverter and BMS? In looking at the name of the inverter/charger currently on my wish list I'm now reading that the "VE.Bus" part of it might be relevant to the communications you're talking about here.

3. It used a contractor so I could use my lithium RV battery to “boost” my chassis battery to emergency start my diesel RV. Needed a very high current- (estimated 500 to 1000 amps at 12v).

I have essentially this same question to Ampster right now but, is there a place in a standard camping vehicle build for a contractor? This thread is the first I've encountered this device in my research/designing so far.

 

[Ampster]

I struggle so hard with trying to sift through these answers and see how/if they apply to my situation. .....

My system powers my house so much of my needs are irrelevant to your situation.

So, is this something that would be relevant to a standard system in a camping vehicle?

As I mentioned above, I think not. Cinergi plans on this being a full time thing.

So, essentially this contactor is essentially acting as a switch to shut off the inverter in the case of a malfunction? A circuit breaker of sorts?

Yes and I think you could get by with something like an Overkill BMS and not worry about contactors. I use those BMSs on a couple of 12 Volt packs. They have a 24 volt version.

I currently have the Victron MultiPlus 24/3000/70-50 VE.Bus Inverter Charger on my wish list for inverter/charger. In reading through the specs on it now, I'm not finding anything that seems to relate to interfacing with a BMS

For your use case having the BMS disconnect to protect the pack should be sufficient.

 

[Ampster]

Rocketman said:
3. It used a contractor so I could use my lithium RV battery to “boost” my chassis battery to emergency start my diesel RV. Needed a very high current- (estimated 500 to 1000 amps at 12v).

I have essentially this same question to Ampster right now but, is there a place in a standard camping vehicle build for a contractor? This thread is the first I've encountered this device in my research/designing so far.

Yes a contactor or AB switch liker used on boats could work. I have not had any direct experience but there are others with much more experience that can give you the details. I am sure you can find threads in the RV Camper section..

 

[Rocketman]

Lance - the CCGX is a "mini-computer" that ties all the Victon products together and puts the info on a easy to read and understand screen - Youtube "Victron CCGX" to see examples. (Victron also has other items in this family - Venus & Cerbo). I also use it to control my Multiplus invertor/changer. It ties all the info from my Battery Monitor, Solar Charge Controller, and Invertor together.

 

[Ampster]

I also use it to control my Multiplus invertor/changer. It ties all the info from my Battery Monitor, Solar Charge Controller, and Invertor together.

I do envy some of the features and integration available on these units. If I did not need all the grid interactive features of my system I would be tempted.

 

[lance]

I am sure you can find threads in the RV Camper section..

Ah HA! This section I've not found yet.... but will!

Lance - the CCGX is a "mini-computer" that ties all the Victon products together and puts the info on a easy to read and understand screen - Youtube "Victron CCGX" to see examples. (Victron also has other items in this family - Venus & Cerbo).

I also use it to control my Multiplus invertor/changer. It ties all the info from my Battery Monitor, Solar Charge Controller, and Invertor together.

This brings me to another lurking question. The BMS for the batteries (Batrium or otherwise) is NOT in lieu of a Battery Monitor like the BMV-712, which is currently on my wish list?

 

[snoobler]

FWIW, I'm 99% sure I'm going with Batrium. I've discovered another poor soul, who has already built the nightmare battery that I seek, and their input has been invaluable. I'm actually procuring even more cells shooting for 53.2kWh total and will end up with 2X 21P14S 48V batteries in parallel. Since I'll need to monitor 28 cells, the Batrium wins out over any other option I see with its ability to communicate with the GX and independently log/trend cell voltages.

 

[HRTKD]

This brings me to another lurking question. The BMS for the batteries (Batrium or otherwise) is NOT in lieu of a Battery Monitor like the BMV-712, which is currently on my wish list?

I can't speak to the higher end BMS, but for the RV world where the Overkill Solar BMS is often used, the Victron BMV-712 is also used. The BMV-712 isn't absolutely necessary, but it does provide a wall display where the BMS does not. If you have multiple batteries - in parallel - then the BMV-712 is a nice way to see the combined state of charge on a single device. In my RV I have two 4s batteries, each with an Overkill BMS and I also have the BMV-712.

 

[Mex Rider]

I can't speak to the higher end BMS, but for the RV world where the Overkill Solar BMS is often used, the Victron BMV-712 is also used. The BMV-712 isn't absolutely necessary, but it does provide a wall display where the BMS does not. If you have multiple batteries - in parallel - then the BMV-712 is a nice way to see the combined state of charge on a single device. In my RV I have two 4s batteries, each with an Overkill BMS and I also have the BMV-712.

Don't forget Victron connect and Overkill's bms android application. I can see my battery state from my living room chair in my van outside with the bms app!