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peterwalent avatar image
peterwalent asked

Multiplus Compact low voltage disconnect? / Battery protect

We're building an electrical system for our van based around Lifeblue lithium batteries and victron components including the multiplus compact 12/2000 (+ solar controller, bmv 712, ccgx). The battery internal BMS has a low voltage disconnect @ 8V, but the manufacturerer recommends a disconnect at 11V so we were thinking to use a Smart Battery protect to provide this. We'd like any and all loads including the inverter to be disconnected in such a situation, had the initial thought of using one 100A smart battery protect to the DC loads, and a 220A Smart Battery Protect to the inverter and therefore AC loads, but we're wondering if the second battery protect to the inverter is necessary or can the multiplus compact itsself be set to disconnect at 11V?

Thanks!

Peter W.

Multiplus-IILithium BatteryBattery Protect
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2 Answers
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @PeterWalent,

I am glad you asked, it is forbidden to connect a Multi to a battery protect. The manual was recently updated to make this more explicit.

The good news is there is a programmable DC voltage shutdown option in the Multi, please see this inverter settings section of the VEConfigure manual:

https://docs.victronenergy.com/veconfigure.html#inverter-settings

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kim-hilding avatar image kim-hilding commented ·

Is it ok to mount the multi plus to the IN pin on the battery protect (directly to the battery)

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Tom avatar image
Tom answered ·

@PeterWalent many of us have made this mistake of placing a BP220 between the battery and Multiplus. Guy is clear you should not do this as it is not safe and can start a fire due to internal damage to the BP. Just program the Multiplus to shut down at your low voltage value and hopefully you have a BMS that can connect a shut down alarm to the Multiplus with the addition of an assistant.

There are other options for a DSR some very expensive and others using a contactor, but really not necessary.

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