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eamon avatar image
eamon asked

MPPT 100/20-48V maximum load current 100mA???

I am looking at using the MPPT 100/20-48V but I noticed that the manual specifies a maximum load current of 100mA for a battery voltage of 36-48V. For 12V and 24V it is 20A.

I cannot imagine why there would be such a difference, and how the unit can be useful at 36V or 48V, with only 100mA of available load current. Unless you are simply not supposed to use the load output in this mode.

Can anyone shed some light on this question?

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5 Answers
wkirby avatar image
wkirby answered ·

From what I understand the load output on the 48V version is supposed to drive a relay. It's not a true metered load output like it's lower Voltage siblings.
I guess the thinking is that there are not so many loads to drive that are rated at 48V.
It's probably the only 48V capable model that actually has a "load" output. The higher power ones don't have the load output at all.

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eamon avatar image eamon commented ·

The manual shows 20A for the 48V version when running up to 24V, and 0.1A when running above 24V. So the 48V model contains a switch that's good up to 20A.

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markus avatar image
markus answered ·

Ah, thanks again @WKirby, I wanted to use the output on this controller for lights, in the "technics shed", and planned to use 4, 5W 12V Bulbs in series. OK, i can cancel this thoughts.


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jamesinwa avatar image
jamesinwa answered ·

I have also wondered about the above regards the output at 48v.

Kirby if using a relay would this then enable a load to be used from the unit at at 48v?

If so what would be the load limit?

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jamesinwa avatar image jamesinwa commented ·

PS Would said load if possible be governed by the same protocols as 12v and 24v as in cut off and reconnect voltage and load disconnect on overload?

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jamesinwa answered ·

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jamesinwa answered · 1 hour ago


I have also wondered about the above regards the output at 48v.

Kirby if using a relay would this then enable a load to be used from the unit at at 48v?

If so what would be the load limit?


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wkirby avatar image wkirby ♦♦ commented ·
The load output would be used to drive a 48V relay coil. The relay coil would be the only load that the MPPT output would "see". The actual load limit that can be connected to the relay contacts depends upon the rating of the contacts of your chosen relay.

When driving a relay, the MPPT will not be measuring the current through the load, only the current through the relay coil which will be less than 100mA anyway.

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petajoule avatar image
petajoule answered ·

This is strange. I came to this topic after reading the load output is limited to 1A (not 0.1A) in 36V or 48V operation, see manual:

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That's still a big WTF??? for me.


You can attach nominally a 1160Wp PV array to it, but handle a load of 48W at best. If you have a 12V system, you can drive 240W (I assume, Victron docs like to be implicit at times) and if you have a 24V system then 480W. Which is ... moment let me compute ... ah: 10 times that.

Very disappointing.



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