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Batrium shunt location and additional packs?
#1
Where is the right place for the current shunt? Between the breakers and the Inverter/Charger is that ok?

If I would hook up additional packs before the shunt, wich don't have Longmons etc. (Dedicated BMS), will they be a problem for the Batrium software?
I like to build some small KWh packs with their own BMS but I want to see overall power usage in Batrium!

Getting closer to have a running system. All Packs completed. Solar panel mounting hardware arrived and final plans are made...
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Maniac_Powerwall: 1x 14S100P 18650 LiIo, 6x 345W LG panels, MPP Solar PIP5048GK, Batrium Watchmon4 BMS
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#2
You can put the shunt in either location. But generally, you probably want to put at least a cutoff between the shunt and the battery to make working on the shunt a little safer. Though you don't have to.
So if you do Battery -> Breaker -> Shunt -> Inverter/Charger, this is fine.

If your Inverter is also a Charger, you need to make sure your breaker is bi-directional. Some breakers will not work as expected with DC when current is flowing in the opposite direction.

You can also have Battery -> Shunt -> Breaker -> Inverter/Charger. However, you might want to put a Cut-off between the Battery and Shunt to make working on the shunt a little safer. This can either be another Breaker or just a kill switch.

If this is a little off, I'm sure others will chime in to correct it, but I believe the above is generally correct.

You can have as many batteries before the shunt as you like, as long as you do not pull more Amps from the combined system than what the shunt can handle. If it's rated for 100A, do NOT go over 100A. Otherwise a) the shunt will get hot b) start becoming inaccurate c) increase in resistance further and making A & B even worse.

The longmons only check individual pack voltage, and they care little of what the whole string is. The only thing that cares about voltage is the shunt and Watchmon. So if you have other batteries, with or without, their own bms, Batrium Watchmon just won't be able to know what's going on with the individual packs. It will only know what the overall voltage of the whole system is and the individual pack voltages of the connected longmons.
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#3
(01-12-2020, 09:55 PM)Korishan Wrote: You can put the shunt in either location. But generally, you probably want to put at least a cutoff between the shunt and the battery to make working on the shunt a little safer. Though you don't have to.
So if you do Battery -> Breaker -> Shunt -> Inverter/Charger, this is fine.

If your Inverter is also a Charger, you need to make sure your breaker is bi-directional. Some breakers will not work as expected with DC when current is flowing in the opposite direction.

You can also have Battery -> Shunt -> Breaker -> Inverter/Charger. However, you might want to put a Cut-off between the Battery and Shunt to make working on the shunt a little safer. This can either be another Breaker or just a kill switch.

Agree with above.  For me, I find it useful to do Battery -> Shunt-trip -> control-box (with shunts and 12v cigarette / USB take-offs / batrium power / etc) -> breakers-to-Charge Controllers  AND -> breakers-to-inverter

* Battery -> Shunt-trip -> control-box - this kills all battery power.  Both + and - (not just one side) is switched off.  Is also Batrium initiated shunt-trip for critical situations.  Very re-assuring when working things to *know* the battery is disconnected 100%.    If you don't have BMS controlled shut-trip you can substitute high amp on/off switches till you get one.
* Control Box -> Charge Controllers -  these breakers (1 per charge controller) isolates the charge controller from the battery AND limits the power going into the battery from the Charge Controller. 
* Control Box -> Inverters - these breakers (1 per inverter) ensure that the inverter DC input is OFF and protect against overload from the battery..  as in if you blow an inverter it can 'short'.  I had cheap Reliable inverter that did this very thing and the breaker saved my battery and probably saved a fire. 
-------------
* PV Array input control box - these breakers (1 per charge controller) isolate the Charge Controller from PV array input.  The Midnite Classics are 'live' with power from either end.


Here's a Midnite Wiring diagram for a control box - showing the shunt.   The GCIF (green wiring) is included in Midnite Controllers themselves but you might want to consider it if you're controller doesn't have one.  The one difference for me is that I have an additional disconnect on the Battery Negative - not just on Battery Positive.   

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#4
Plan quite the same but charger and inverter is combined. But have breakers for panels and breaker with batrium controlled shunt trip for DC side both positive and negative. Also breakers in and out of the inverter/charger for AC.
My Powerwall Build Thread

Maniac_Powerwall: 1x 14S100P 18650 LiIo, 6x 345W LG panels, MPP Solar PIP5048GK, Batrium Watchmon4 BMS
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