Smart BMS with Wall mounted monitor?

[Luk3jay]

Hi Everyone, I've just purchased 4x 3.2v 200ah LifePo4 cells which I'll use to make a 12v bank.

I've not decided on a BMS as of yet, I'm not convinced on the DALY and have seen some no brand 'designed for medical' ones on ebay which look good.
this will be for my campervan and one main consideration is that I'd like to have a battery monitor on the wall.
I'd like this to show:
1: state of charge/ capacity remaining in %
2: live current draw (or charge current)

I currently have this on my lead acid battery pack and it's done via the solar charge controller display which I really like. I don't think it'll work as accurately with LifePo4 battery due to the constant voltage. It dawned on me that it may be best to use a BMS which has some kind of wall mounted display? Does anyone know of any?

Otherwise, can anyone recommend a wall mount battery monitor that works well with LifePo4?

Thanks.

 

[sunshine_eggo]

Hi Everyone, I've just purchased 4x 3.2v 200ah LifePo4 cells which I'll use to make a 12v bank.

I've not decided on a BMS as of yet, I'm not convinced on the DALY and have seen some no brand 'designed for medical' ones on ebay which look good.
this will be for my campervan and one main consideration is that I'd like to have a battery monitor on the wall.
I'd like this to show:
1: state of charge/ capacity remaining in %
2: live current draw (or charge current)

I currently have this on my lead acid battery pack and it's done via the solar charge controller display

I doubt it's accurate unless it's counting current in AND out of the battery. It's probably just voltage based and worthless in terms of actual SoC even for lead.

which I really like. I don't think it'll work as accurately with LifePo4 battery due to the constant voltage. It dawned on me that it may be best to use a BMS which has some kind of wall mounted display? Does anyone know of any?

Nothing like what you are describing.

What about an old phone or cheap tablet running the bluetooth app?

 

[jamiegreen]

Personally I'd go for a Victron bmv712, at least then you know your getting accurate readings, and has some useful other features like a programmable relay etc.

 

[Luk3jay]

Personally I'd go for a Victron bmv712, at least then you know your getting accurate readings, and has some useful other features like a programmable relay etc.

Thank you. since writing this post I came across the 702 which seemed like it will work. Do you know what the difference is between the 702 and 712? Thank you

 

[Luk3jay]

I doubt it's accurate unless it's counting current in AND out of the battery. It's probably just voltage based and worthless in terms of actual SoC even for lead.

The charge controller sits between the battery and the load so gives very accurate readings of incoming solar, load, and battery current (in or out)

Nothing like what you are describing.

What about an old phone or cheap tablet running the bluetooth app?

That would be a last resort and seems pretty clunky to me. I'd prefer something that can be properly mounted to the wall and integrated.

 

[jamiegreen]

712 has bluetooth and don't think the 702 does? but don't quote me on that, should be in the specs somewhere. If that is the case go for the one with BT because they have a brilliant customisable app.

 

[jamiegreen]

The charge controller sits between the battery and the load so gives very accurate readings of incoming solar, load, and battery current (in or out)


That would be a last resort and seems pretty clunky to me. I'd prefer something that can be properly mounted to the wall and integrated.

From what I've read the SOC readings from most BMS's is.. questionably accurate, certainly not as accurate as a dedicated shunt such as the 712 etc. Victron also makes a colour screen display (ccgx) but far from cheap and more useful if running other victron equipment like their inverters etc.

 

[Luk3jay]

From what I've read the SOC readings from most BMS's is.. questionably accurate, certainly not as accurate as a dedicated shunt such as the 712 etc. Victron also makes a colour screen display (ccgx) but far from cheap and more useful if running other victron equipment like their inverters etc.

Thanks. This is very useful info! I guess I was incorrect in my assumption that the BMS would... you know... be aware of the battery SOC ?

Looks like the 712 is the one to go for. Just as I thought my electrical system was done, it's suddenly become very expensive again

 

[sunshine_eggo]

712 has bluetooth and don't think the 702 does? but don't quote me on that, should be in the specs somewhere. If that is the case go for the one with BT because they have a brilliant customisable app.

702 = battery voltage and temperature or second battery monitor.
712 = 702 + bluetooth.

 

[sunshine_eggo]

Thanks. This is very useful info! I guess I was incorrect in my assumption that the BMS would... you know... be aware of the battery SOC ?

Looks like the 712 is the one to go for. Just as I thought my electrical system was done, it's suddenly become very expensive again \

Victron also has a smartshunt that is similar to a 712 without the physical display.

 

[Luk3jay]

Thanks. I'm going to go with the 712. It's a shame I can't see SOC and current draw etc at the same time like I can now, but it's a compromise I can live with.

Thank you

 

[Luk3jay]

So after some research, I'm also considering the Pico monitor from Simarine. It's expensive but looks really great.

Battery monitor PICO for boats, campervans, RVs - Simarine

The PICO battery monitor delivers all data about your batteries (voltage, SOC, time to charge & discharge ...), tank levels, fridge

simarine.net

 

[Just John]

From what I've read the SOC readings from most BMS's is.. questionably accurate, certainly not as accurate as a dedicated shunt such as the 712 etc. Victron also makes a colour screen display (ccgx) but far from cheap and more useful if running other victron equipment like their inverters etc.

Most "smart" BMS can be calibrated, which makes them more accurate. However the Victron shunt is probably the best on the market.

If it meets your needs, some cheaper alternatives work. They won't have near the features (or the price).

https://smile.amazon.com/gp/product/B07FGFFHC6/

 

[jamiegreen]

@Luk3jay Did you decide on which monitor you were going to use yet? Just a heads up since I've found some software for my BMS to communicate with my Victron equipment I no longer need my BMV712 so will probably sell if anyone is interested.

 

[Luk3jay]

@Luk3jay Did you decide on which monitor you were going to use yet? Just a heads up since I've found some software for my BMS to communicate with my Victron equipment I no longer need my BMV712 so will probably sell if anyone is interested.

I will PM you. Thanks.

 

[Luk3jay]

So I ended up going for a JBD BMS and noticed they have a touch screen interface which is pretty cheap.
I've bought it to see what it's like and will report here. the Victron 712 will be my second choice if this isn't great.