Best shunt option?

[nicoloks]

Hi All,

The BMPro BMS in my van is not lithium ready, so the BMPro shunt that integrates with it that I bought back when I had an AGM is no longer accurate for tracking SOC of my new lithium battery.

I was about to buy the Victron 500A SmartShunt, however before doing so though I just wanted to check if there where any other Bluetooth shunts with good phone apps were available?

 

[SparkyJJO]

Often times the BMS has its own built in, so if you just want to use bluetooth on your phone, just use the BMS.

 

[sunshine_eggo]

Hi All,

The BMPro BMS in my van is not lithium ready, so the BMPro shunt that integrates with it that I bought back when I had an AGM is no longer accurate for tracking SOC of my new lithium battery.

Why? If you can program the capacity, and if it works like a shunt by counting Ah in and out, it should work fine.

The Victron shunts have additional features like Peukert, charge efficiency and temperature coefficients that make them notably more accurate than other shunts for lead acid.

I have a BMV-702 to go with my Victron ecosystem, but unless you need the added features, they may not be the best choice unless you want the bluetooth feature.

 

[nicoloks]

Thanks for the replies. The impression I was given by BMPro support was the Shunt is fine, it is the BMS I have it paired with that is unable to calculate SOC properly. This is their reply when I asked them about connecting a lithium battery to my J35B BMS.

The J35B will put a charge into a lithium, but the algorithms and coulomb count will throughout the state of charge and display incorrectly.

The problem with my current BMPro shunt is that it only pairs with a BMPro BMS. I cannot access it directly. I figure if I get something like the Victron, then I can access it direct and it'll give me accurate readings no matter what battery system I have now or in the future. Data out of the BMPro and their app itself is very rudimentary, Victron seem to be quite polished.

 

[sunshine_eggo]

I tried to make sense of their products, but I gave up several minutes. It appears that you can configure battery capacity via the JHub app. If they have hard-coded algorithms designed solely for lead-acid, then yes, it would not be accurate.

If you have any interest in a physical display, consider a BMV-712 (spendy). If you're fine with the bluetooth access, then a smartshunt is likely the best option, but there are many complaints about bluetooth range (BMV-712 has great range). They have recently implemented two channel logging for up to 45 days worth of data, e.g., if you have voltage and current selected, it will keep a 45 day rolling history even when the app is inactive (used to only work when app was active).

 

[nicoloks]

I tried to make sense of their products, but I gave up several minutes. It appears that you can configure battery capacity via the JHub app. If they have hard-coded algorithms designed solely for lead-acid, then yes, it would not be accurate.

If you have any interest in a physical display, consider a BMV-712 (spendy). If you're fine with the bluetooth access, then a smartshunt is likely the best option, but there are many complaints about bluetooth range (BMV-712 has great range). They have recently implemented two channel logging for up to 45 days worth of data, e.g., if you have voltage and current selected, it will keep a 45 day rolling history even when the app is inactive (used to only work when app was active).

Glad you found their product lineup as confusing as I did, very daunting when it was my first exposure to 12v systems. Not to mention expensive, especially for what they are. It was going to cost me over $1000AUD to upgrade to the lithium compatible J35B-L BMS, even then I'd still have the same PWM based solar charge controller with a 20A input limit.

I bought a lithium ready rebadged SRNE 40A MPPT solar charge controller with Bluetooth dongle for $100 on sale. It is no Victron (or even Renogy) in terms of integration, however significantly more capable and their basic phone app is a long way ahead in terms of functionality than the BMPro.

Thanks for the tips. I'll give th BMV-712 a look. Would be good to have a physical display for a quick check of status.

 

[sunshine_eggo]

Don't get too hung up on "lithium ready" "Lithium compatible" etc.

LFP is mostly a drop-in replacement for lead acid. Given that they have their own BMS, they can protect themselves from anything chargers can throw at them.

Generally, if your charger can be configured for 14.2-14.4V absorption and float at 13.6V, it's pretty much fine.

 

[nicoloks]

Thanks again, I'm starting to see that now. Lot manufacturers seem to lay it down pretty thick that you need a lithium compatible charger for lithium batteries. From my understanding now it seems so long as your lead acid charger does not have any higher voltage desulphation or equalisation stages in its charge profile and has the bulk and float charges as you say, there shouldn't be any real issues.

The J35B is super basic in that battery capacity is the only parameter you can change as a user. Rest seems to be baked in, however luckily in being so basic it does not have desulphation or equalisation stages and has a float of 13.6v and bulk of 14.4v.

The solar charge controller was worth changing out regardless as I'll now be able to put 3 panels on my van roof series connected. Should produce a meaningful amount of power even on cloudy days.

 

[nicoloks]

If you have any interest in a physical display, consider a BMV-712 (spendy). If you're fine with the bluetooth access, then a smartshunt is likely the best option, but there are many complaints about bluetooth range (BMV-712 has great range). They have recently implemented two channel logging for up to 45 days worth of data, e.g., if you have voltage and current selected, it will keep a 45 day rolling history even when the app is inactive (used to only work when app was active).

One question about the 45 day rolling data. Is that feature only available with the BMV-712, or do you get that with the Shunt only as well?

 

[sunshine_eggo]

VictronConnect changelog and beta releases [Victron Energy]

www.victronenergy.com

v5.70 (Released officially)​

2022-07-13
Changes

• Support Android 12 new Bluetooth permissions. This allows VictronConnect to scan for nearby Victron Bluetooth products without having to request location permissions. Only applies to Android 12 pho
• Add Danish & Russian translations
• Improve Venus to xlsx converter: Conversion can now cope with partially corrupted VRM log files
• Several internal improvements
• New feature: Sort local products list by name and group user own products. To add a product to the “own” group VictronConnect has to connect to it at least once.
• New stored trends feature:
  • Trends data is kept stored in the product for up to 46 days for most products, except the Smart Battery Sense, there its 181 days.
  • SmartSolar, BMV-712 and SmartShunt:
    • SmartSolar support trends for Batt. Voltage, Current and Temperature, as well as Load output current, PV voltage and PV current.
    • BMV-712 and SmartShunt support trends for Battery voltage, Current, State of Charger % as well as the Aux input (battery temp, or midpoint deviation, or starter battery voltage).
    • Interval configuration is equal for above products, and in detail is:
    • 2m at 1s interval (RAM only)
    • 2h at 30s interval
    • 1d at 5m interval
    • 45d at 30m interval
  • Smart Battery Sense trends:
    • Support trends for Battery voltage and Battery temperature.
    • 2m at 1s interval (RAM only)
    • 2h at 30s interval
    • 1d at 5m interval
    • 180d at 30m interval

 

[JoeHam]

I’m a fan of the SmartShunt.

May find it cheaper somewhere else but here’s a link :

https://www.amazon.com/dp/B0856PHNLX

 

[Herb]

I'm pretty happy with the smart shunt, the only think that I would like to see is for it to be able to store the current SOC status for retrieval in case there is a power disconnect either scheduled or not. I recently had to do a top balance of my bank (in series parallel) and had to disconnect the shunt power cable and lost all SOC data, since it was a scheduled event it didn't matter, but if a fuse blows or something of that nature where the power is lost you would loose your current SOC status, not a biggie, just wish it would have that feature if all possible. Some more economical battery monitors are able to store this information.