Victron Multiplus external controls.

[Craig]

I am wondering how the external control inputs on the Victron multi plus units work. Can they accept a direct 12v signal from my Chargery or do I need to use an opto-coupler or something. With my Midnight classic the 12v signal works perfectly. I am trying to create a list of devices that play well with a Chargery or Chargery like device.

I was hoping anyone who has one or @Justin Laureltec could help please.

 

[nebulight]

I wouldn't feed 12V to the inputs, I'd just use an optocoupler board for all to charge and allow to discharge powered by the 12v of the BMS outputs. I have the output of my BMS (discontinued MiniBMS) that powers this optocoupler board:

Amazon.com: NOYITO PC817 4-Channel Optocoupler Isolation Board Voltage Converter Adapter Module 3.6-30V Driver Photoelectric Isolated Module: Computers & Accessories

Buy NOYITO PC817 4-Channel Optocoupler Isolation Board Voltage Converter Adapter Module 3.6-30V Driver Photoelectric Isolated Module: Serial Adapters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

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I split the allow to charge to two of those ports and allow to discharge to the other two. Then one set of each to go the Multiplus with the two-signal BMS assistant, and the other two go to Batteryprotects (one for DC loads and one for charge sources MPPT and DC-DC charger)

You can find these cheaper on Ali.

 

[Craig]

I wouldn't feed 12V to the inputs, I'd just use an optocoupler board for all to charge and allow to discharge powered by the 12v of the BMS outputs. I have the output of my BMS (discontinued MiniBMS) that powers this optocoupler board:

Amazon.com: NOYITO PC817 4-Channel Optocoupler Isolation Board Voltage Converter Adapter Module 3.6-30V Driver Photoelectric Isolated Module: Computers & Accessories

Buy NOYITO PC817 4-Channel Optocoupler Isolation Board Voltage Converter Adapter Module 3.6-30V Driver Photoelectric Isolated Module: Serial Adapters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

I split the allow to charge to two of those ports and allow to discharge to the other two. Then one set of each to go the Multiplus with the two-signal BMS assistant, and the other two go to Batteryprotects (one for DC loads and one for charge sources MPPT and DC-DC charger)

You can find these cheaper on Ali.

Does the ootocoupler reduce volts or just isolate?

Thanks for the input!

 

[nebulight]

It's for isolation.

 

[Dzl]

Two places I would look for info are (1) Victron's documentation (2) The electrodacus forum, many people remotely controlling Victron equipment over there.

 

[Heap64]

Very glad to see nebulight join our Forum! I have actually been referencing his setup from a couple other forums and have been leveraging that for my planned upgrades when I go to Lithium and eventually add a Victron Multiplus into our travel trailer.

Here is my current thoughts put to paper.

I'm also considering either the Cerbo GX and Touch 50, or possibly the Raspberry PI DYI solution as well. Those aren't shown in the current version of the design.

 

[Craig]

so you guys are saying it will work fine just use an opto-coupler for isolation safety?

 

[mapguy525]

Very glad to see nebulight join our Forum! I have actually been referencing his setup from a couple other forums and have been leveraging that for my planned upgrades when I go to Lithium and eventually add a Victron Multiplus into our travel trailer.

Here is my current thoughts put to paper.

I'm also considering either the Cerbo GX and Touch 50, or possibly the Raspberry PI DYI solution as well. Those aren't shown in the current version of the design.

can you link to the other forums?

 

[nebulight]

so you guys are saying it will work fine just use an opto-coupler for isolation safety?

Yes. The Multiplus is an expensive inverter/charger. A $2 board to protect your $1200 inverter/charger is worth it.

 

[Airtime]

I am wondering how the external control inputs on the Victron multi plus units work. Can they accept a direct 12v signal from my Chargery or do I need to use an opto-coupler or something. With my Midnight classic the 12v signal works perfectly. I am trying to create a list of devices that play well with a Chargery or Chargery like device.

I see nebulight already addressed the optocoupler advice, I'm using the same board. In fact I may have gotten that tip from nebulight.

What I'd like to add based on what you are trying to capture is that the Victron Multiplus is the only inverter/charger that enables separate independent control of the charger and the inverter. So the BMS can disable just the charger at HVD, or just the inverter at LVD. No need for large switches and precharge in the DC path, or hacking power switches to wire in an on/off control that disables both. This works great for BMSs that have separate control lines for charge enable and discharge enable.

Victron actively supports use of the Multiplus by non-Victron BMSs. In fact they have an app note on it:
https://www.victronenergy.com/uploa...battery-systems-to-Multis-and-Quattros-EN.pdf

Note that newer Multiplus units actually have an Aux 2 as well as an Aux 1, along with the Temp Sense input. So you don't need to use the Temp Sense input for this control, you can just use the two Aux inputs. The software gives you the option to select either. It was very simple to set up and just works.