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-   -   MPPT - what to connect to load? (

gauvins 28-06-2018 09:52

MPPT - what to connect to load?
Just installed a Victron MPPT smart controller. It has a "load" output, that can be programmed in multiple ways.

I've connected a computer+USB charger. The idea being that I don't want to charge batteries from batteries, for the sake of efficiency.

I am wondering if I should also connect the water maker to load. It is never used at night, so that would appear to make sense.

My question is : does it make a difference for the batteries? I thought that when solar is plenty, electricity would flow to loads without drawing on the battery. So there would be no meaningful difference between the regulator's "load" and the usual connection via a distribution panel.

Can someone explain to me what "load" is meant to do?

sparrowhawk1 28-06-2018 12:42

Re: MPPT - what to connect to load?
Like you said it's programmable so you can use it for things that you want on momentarily. one of the best uses is an anchor light, you can program it to come on at Sunset and off at dawn. The cheap ones will just do Sunset and Dawn. Another idea would be to hook up your water maker and have it turn off at say 3 p.m. allowing your batteries to be totally charged Before Sunset.

smac999 29-06-2018 02:09

Re: MPPT - what to connect to load?
on a boat I would not use it.

it's for like a porch light on a cabin.

I doubt the amps would handle a water maker. maybe trigger a relay.

Bleemus 29-06-2018 09:01

Re: MPPT - what to connect to load?
Just to clarify what the Load function of a Victron controller is used for as there seems to be some confusion.

From the manual..

1.3 Load output

Deep discharge of the battery can be prevented by connecting all loads to the load

output. The load output will disconnect the load when the battery has been discharged

to a pre-set voltage.

Alternatively, an intelligent battery management algorithm can be chosen: see Battery


The load output is short circuit proof.

Some loads (especially inverters) can best be connected directly to the battery, and the

inverter remote control connected to the load output. A special interface cable may be

needed, please see section 3.6.

john61ct 29-06-2018 18:25

Re: MPPT - what to connect to load?
Victron's output is probably fine for any consumer type, but current is limited (10A? see the specs for your model).

A generic LVD can substitute the same functionality at higher or lower amps, priced accordingly, and good ones are adjustable.

The purpose is to isolate heavier / less essential loads as SoC drops, so the lighter / more essential consumers can keep going longer, without reducing bank lifetime by dropping to a too-low SoC before the next charge cycle.

john61ct 29-06-2018 18:27

Re: MPPT - what to connect to load?
Many cheap SCs' output is not only current-limited, but suitable for only certain loads, usually resistive only I believe.

Therefore the whole feature concept gets disparaged, but on quality units it is much more useful.

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