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External BMS for drop in replacement Lithium Batteries


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Hi Everyone

I have been following threads on the forum for a while, and have been helped immensely by it.

I have recently completed an upgrade  to my home inverter setup, including a upgraded inverter and some new out feed wiring. The inverter that I have installed has two outfeed circuits - a "Main Power" and a "Smart Power" Circuit. From the manual, it seems that the "Smart Circuit" is the essential loads - so when the inverter is running on battery, it will cut the "Main Loads" at a set battery level and just run the other circuit to conserve battery power. This appeals to me greatly, as my pool pump runs on the inverter, and if we have load shedding during a cloudy day, it may drain my batteries a lot (i do not have a lot of battery capacity at the moment).

The batteries that I have are lithium drop in replacements for AGM batteries (Hubble S100 x 2). According to Hubble the batteries do have an integrated BMS, but they do not have any comms ports. The inverter requires a comm port for the essential load cut-over, as this is set on % of battery backup available. If the comm port is not active, this option is  not available in the setting on the inverter.

So after this very long story, I would like to know if there is a type of "plug and play" external BMS that could solve this problem? Something that could be connected inline with the batteries,  be set with the appropriate parameters, has a compatible comm port and could enable use of the "Smart Circuit.

I am very much hobbying along with this project, and i would hate to be forced to spend R12k or so replacing perfectly good batteries just for this what if scenario. On the other hand, the "Smart Circuit" logic is very appealing, and seems like something i would really like to get going.

Details on my current system:

1. Inverter (new -installed last weekend) - Sun Solar S2524 (4.2 kW load, 6.2 kW MPPT at 60-500V, 24V battery at 12A)(https://solarwarehousesa.com/products/hybrid-inverter-24v-4-2-kva-4200w-mppt-120a-inverter-pure-sine-wave-sun-solar?variant=48852775272769&currency=ZAR&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gad_source=1&gclid=CjwKCAjwm_SzBhAsEiwAXE2Cv_GUYULcSD2IFJhJFB4Fr41qOV9LFgPG_eiFQl2aZ5Y7kElppyQGwxoCsZ8QAvD_BwE)  

2. Solar Panels - 4 off Jinko 555W connected in series (40V per panel for string voltage of 160V) - North facing on roof m(https://www.solarpanelenergy.co.za/docs/Jinko 555W Datasheet.pdf)

3. Batteries - 2 off Hubble S100 connected in series with Hubble battery balancer ( https://powerprovider.co.za/product/hubble-s-100a-and-24v-battery-balancer-bundle/)

4. Connections and switching -

       4.1 Grid to inverter through 20A plug socket from main DB

       4.2 Panels through Solar Combiner Box with surge arrestors, fuses and circuit breaker (4mm string cable with MC4 connectors)

        4.3 Outfeed - 2 x DB boxes (one for "Main Feed", one for "Smart Feed") each box has manual switch over to grid, earth leakage and 10 amp or 20 amp breakers for circuits as                         appropriate 

Thank you guys in advance!

 

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To connect an actual BMS, you will need to open up the batteries to access the cell terminals, which is not a great idea unless you really know what you are doing.

What you probably want is a coulomb counter. Like the Victron Smart Shunt - but Victron only talks to other Victron products.  I have done a quick search for coulomb counters with generic inverter comms, but don't really see anything.

Can you not operate the inverter in voltage monitoring mode for smart circuit switching?

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Posted (edited)

Unfortunately there is no option to set a voltage for the smart circuit monitoring, the manual states that the battery comm terminal must be connected. There also is no option to set voltages for this in the settings menu - it goes straight past that option in the menu.

I really do not want to open the batteries or mess with any of the internals - I am 100% sure that I will not know what i am doing. 

The coulomb counter sounds like exactly what I have in mind.

The inverter has the following comm ports:

Available Ports: RS232/RS485/WIFI/GPRS/LITHIUM BATTERY

Please forgive me if this is a dumb question, as the Victron Smart Shunt has a V.E. Direct port and the inverter has a RS232 port, could something like this work?

https://www.victronenergy.com/accessories/ve-direct-to-rs232-interface

If it could, this may be a solution for R3 000-00 as opposed to R12 000-00, which is a much easier pill to swallow!

Edited by AppleJack
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1 hour ago, AppleJack said:

Unfortunately there is no option to set a voltage for the smart circuit monitoring, the manual states that the battery comm terminal must be connected. There also is no option to set voltages for this in the settings menu - it goes straight past that option in the menu.

I really do not want to open the batteries or mess with any of the internals - I am 100% sure that I will not know what i am doing. 

The coulomb counter sound like exactly what I have in mind.

The inverter has the following comm ports:

Available Ports: RS232/RS485/WIFI/GPRS/LITHIUM BATTERY

Please forgive me if this is a dumb question, as the Victron Smart Shunt has a V.E. Direct port and the inverter has a RS232 port, could something like this work?

https://www.victronenergy.com/accessories/ve-direct-to-rs232-interface

If it could, this may be a solution for R3 000-00 as opposed to R12 000-00, which is a much easier pill to swallow!

Have a word with @BritishRacingGreen for comms related matters. He knows his stuff.

If ever you do decide to open those S-100s then you can get a JK BMS with RS485. Refer to Andy on YouTube Off grid garage for details. 

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5 hours ago, AppleJack said:

Hi Everyone

I have been following threads on the forum for a while, and have been helped immensely by it.

I have recently completed an upgrade  to my home inverter setup, including a upgraded inverter and some new out feed wiring. The inverter that I have installed has two outfeed circuits - a "Main Power" and a "Smart Power" Circuit. From the manual, it seems that the "Smart Circuit" is the essential loads - so when the inverter is running on battery, it will cut the "Main Loads" at a set battery level and just run the other circuit to conserve battery power. This appeals to me greatly, as my pool pump runs on the inverter, and if we have load shedding during a cloudy day, it may drain my batteries a lot (i do not have a lot of battery capacity at the moment).

The batteries that I have are lithium drop in replacements for AGM batteries (Hubble S100 x 2). According to Hubble the batteries do have an integrated BMS, but they do not have any comms ports. The inverter requires a comm port for the essential load cut-over, as this is set on % of battery backup available. If the comm port is not active, this option is  not available in the setting on the inverter.

So after this very long story, I would like to know if there is a type of "plug and play" external BMS that could solve this problem? Something that could be connected inline with the batteries,  be set with the appropriate parameters, has a compatible comm port and could enable use of the "Smart Circuit.

I am very much hobbying along with this project, and i would hate to be forced to spend R12k or so replacing perfectly good batteries just for this what if scenario. On the other hand, the "Smart Circuit" logic is very appealing, and seems like something i would really like to get going.

Details on my current system:

1. Inverter (new -installed last weekend) - Sun Solar S2524 (4.2 kW load, 6.2 kW MPPT at 60-500V, 24V battery at 12A)(https://solarwarehousesa.com/products/hybrid-inverter-24v-4-2-kva-4200w-mppt-120a-inverter-pure-sine-wave-sun-solar?variant=48852775272769&currency=ZAR&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gad_source=1&gclid=CjwKCAjwm_SzBhAsEiwAXE2Cv_GUYULcSD2IFJhJFB4Fr41qOV9LFgPG_eiFQl2aZ5Y7kElppyQGwxoCsZ8QAvD_BwE)  

2. Solar Panels - 4 off Jinko 555W connected in series (40V per panel for string voltage of 160V) - North facing on roof m(https://www.solarpanelenergy.co.za/docs/Jinko 555W Datasheet.pdf)

3. Batteries - 2 off Hubble S100 connected in series with Hubble battery balancer ( https://powerprovider.co.za/product/hubble-s-100a-and-24v-battery-balancer-bundle/)

4. Connections and switching -

       4.1 Grid to inverter through 20A plug socket from main DB

       4.2 Panels through Solar Combiner Box with surge arrestors, fuses and circuit breaker (4mm string cable with MC4 connectors)

        4.3 Outfeed - 2 x DB boxes (one for "Main Feed", one for "Smart Feed") each box has manual switch over to grid, earth leakage and 10 amp or 20 amp breakers for circuits as                         appropriate 

Thank you guys in advance!

 

Can you check in your manual if Pylontech  canbus is supported on the BMS (Lithium Battery) port. 

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