question

ary avatar image
ary asked

Battery Protect connected to a inverter (using LYNX Dist.) schematic

Hi,

I want to make a 12v battery system, charged from PV via MPPT (two Panels in series 400W each).

The idea is to use is in case of a blackout for home appliances like fridge, TV ....

The system is based on folowing components:

- Victron LYNX Dist.

- Enclosed DC 16A Switch - DC Disconnect (PV Disconnect from MPPT)

- Victron smart shunt

- Victron MPPT 150/70 charge conntroller

- Victron 100A smart BP.

- Victron ON/OFF Master Battery Switch (275A)

- DIY lifepo4 batteries with BMS (JBD or JK BMS)

- 2000W DC-AC(230V) Inverter with remote switch (non Victron)

Can I use the BP in that constellation ? Or should I avoid using the component ?

Generally, the BMS has the role of keeping the battery status under the eye (all 4 cells individually with balance option) so in case of any under voltage of any cell it will cut off the "-" wire which then leads to a system shutdown (load disconnect).

My question are:

- what happens with the MPPT controller if the battery gets disconnected and the Solar PV are still providing power to the component ?

- how to connect the BP in such a system - schematic would be great !?

- should I connect the Inverter directly to the battery via LYNX Dist (with fuse of course)?


I have read some posts on the internet which say that the BP should not be connected directly to the inverter (inline) because of an inrush current. Can someone please explain how should this be done properly !

If this is the case the BP is just useless in my case or am I missing here something ?

regards

Andrzej






Battery ProtectSolar Panelinverter current drawdischarge levelschematics
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1 Answer
JohnC avatar image
JohnC answered ·

Hi @ARY

I'm not so sure the BP is the right device for you. There's a range of example schematics on the Victron website catalogued by product as best they can, and you might get a feel for how it's normally used there.. https://www.victronenergy.com/support-and-downloads/systems

Trouble is, most Victron systems use Victron inverters +/or chargers, and they're not treated as a generic might be. Come back though as you need.

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ary avatar image ary commented ·

Hi,

Thx for your answer !

What is the purpose of the BP then ?

I would just use the BP as a trigger for shutting down the inverter in case of battery low voltage scenario, using a relay so that the BP would not be directly connected to the DC LOAD. I found a guy who did so but I am not sure if it makes sense.

https://www.youtube.com/watch?v=5TcwBHgRrfY&t=782s

I just need to hack the remote switch on the inverter (RJ12) to trigger a signal from the BP (L,H,Alarm).


regards

Andrzej


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JohnC avatar image JohnC ♦ ary commented ·
@ARY

I think they're mostly used for dc loads. Use with Victron inverters isn't really necessary as they have internal switching features, and for inverter/chargers they aren't used because they can't handle reverse current.

I didn't get too far into that clip as it stopped loading, but the precharge circuit is a common thing to prevent the initial sparking. The other stuff got too painful.

Sorry I can't help you more.

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