question

jens-due avatar image
jens-due asked

Battery Switch ON/OFF 275A

The Battery Switch ON/OFF 275A 12-48V

Can i use it in a 48V system with a Multiplus II

Multiplus-IIMPPT ControllersESS48v battery
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4 Answers
marekp avatar image
marekp answered ·

When you look at the description of this switch:

Battery Switch ON/OFF 275A 12-48V

You will see the voltage range (12-48V).

Does it mean that this switch cannot be used below 12V?

This switch is design for systems with battery nominal voltage of up to 48V.

The much bigger problem with this switch is that it will fail when you try to connect any battery to the inverter with empty DC capacitors.

The inrush current will weld this switch shut.

You have to install a "pre-charge" switch that will charge DC capacitors through a resistor first.

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klim8skeptic avatar image
klim8skeptic answered ·

Apparently not, DC voltage rating of 48v.

Battery switch 48v.

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marekp avatar image marekp commented ·

Is this "48V" say that this is the max DC voltage, or it just say it is for 48V systems?

If the later, I would say it is OK to use it with 48V battery.

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alexs avatar image
alexs answered ·

I have exactly the same question, except I've just purchased a 48V 10kVA Quattro and the rest of the system (with 10 of these switches) before I thought about whether these switches are rated for 48V Max, or are fine a 48V system where voltages are approaching 60V.

Does anyone have a definitive answer from Victron?

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gazza avatar image
gazza answered ·

There are a lot of "battery ON/OFF/changeover" switches that are sold on the usual online stores. The specs are quite confusing. Since a lot of these relatively cheap battery switches are designed for 12V changeover, such as to/from a leisure battery in a motorhome etc they are advertised as 12v/275A for example. BUT in the small print spec they quote 12,24,48v use and one also had this statement as below...


Generally the current rating is about the amount of metal conductor and the voltage rating is about insulation between the conductors, ie breakdown voltage through the air/plastic? I seriously wonder if they actually do test these cheap switches to the limit? Maybe 60v was the biggest source they had available? Either way I think you could get one tested by a "competent friend" or do your own tests to provide confidence one way or the other....

screen-shot-2022-09-05-at-093657.png


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