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manu avatar image
manu asked

Why does the SmartSolar 100/30 MPPT have no load output?

I recently bought to my existing system a Victron SmartSolar Charge controller MPPT 100/30. The idea was to replace the old controller with this one. Well, now when I wanted to install it I noticed there's no incoming place for the cables going to the load (lights, usb and so on). In all the controllers I've had before there's been incoming connectors for the battery, the panels and the load. So sorry for not getting this, but how do I do this, what is missing?

MPPT Controllerswiringsmart solar set-up help
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4 Answers
abrahamsolar avatar image
abrahamsolar answered ·

Hi from the USA, @Manu. The function you are wishing was present is called "low voltage load disconnect" or "low voltage disconnect". This function is important for those with DC loads & not important for those who are inverting for all their loads (since the inverters have a built in low voltage cutoff.)

Some DC charge controllers have the LVD feature built in & others do not. Those that have it built in can only LVD the same amperage for which the solar charge controller is rated. Sometimes that's not enough but if it is enough, the wiring is nice & simple.

Victron has a set of products called "Battery Protect" which handle the LVD functions as a separate solution in varying amp ratings. The Battery Protect product needs a properly rated fuse or breaker at the battery plus terminal...& suitably sized wires.

The "smart" version Battery Protect is easier to program using a smart phone with Bluetooth. There's a dandy Victron video on youtube about how to program the normal Battery Protect products.

Sunny Days~

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abrahamsolar avatar image
abrahamsolar answered ·

Yep, sorry to say, Manu, you have the wrong controller if you don't want to revise your wiring. Low voltage disconnect is of course important to protect the battery from over-depletion...so it's worth getting that working again.

You mentioned switching to a "smaller" unit & @Robert mentioned that 20a is the biggest Victron MPPT control with the LVD feature. If your prior controller was 20a rated (with the "battery side" fuse also being 20a) & if your DC lights, etc. never caused the fuse to blow...you could safely proceed with that same amp rating for your replacement controller.

If your prior controller was 30 amp rated, however, you risk blown fuses or >possible< controller damage if you go smaller this time. To know for sure about that you could measure the DC load amps (or calculate them on paper) with everything running at one time.

Meten is Weten as our Dutch friends would say: Measuring is knowing.

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Robert avatar image
Robert answered ·

Hello @Manu.

The unit you have does not have a load output, as you have discovered. The highest load output on a Victron MPPT is currently 20A, 100/20.

You can use the TX pin on the VE.Direct connector to drive a Battery Protect unit. See https://www.victronenergy.com/live/victronconnect:mppt-solarchargers#tx_port_function . Useful for the streetlight function. Otherwise just use the BP without TX pin connection as a low voltage disconnect as @abrahamsolar has mentioned.

Robert

MI Battery Engineering


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manu avatar image manu commented ·

hello Robert,

Thanks for your answer! So like I wrote anonther user:

Since I'm not an expert: this means that for being able to use my current DC loads (the wiring is all done, since I used to have another controller) I need to change my SmartSolar 100/30 to a "smaller" one that has the load output option, correct? I do have an inverter as well for AC loads (Phoenix 12/375) but I use that only occassionally when charging a computer and so on.

best,

Manu


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manu avatar image
manu answered ·

Ok, thanks abrahamsolar!

Since I'm not an expert: this means that for being able to use my current DC loads (the wiring is all done, since I used to have another controller) I need to change my SmartSolar 100/30 to a "smaller" one that has the load output option, correct? I do have an inverter as well for AC loads (Phoenix 12/375) but I use that only occassionally when charging a computer and so on.

best,

Manu

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JohnC avatar image JohnC ♦ commented ·

You could just run your load wires into the BATT terminals. You may have to 'encourage' them to fit with the existing connectors needed therein, so take care doing that.

I wouldn't revert to a lesser model just for those LOAD terminals. Victron have stated not to use them for inverters, likely because of the connection spike doing so, and having their output trip.

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