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MapisM

MapisM

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I'm learning to deal with the just installed Multiplus inverter, with its "digital multi control" panel, and can't understand one thing:
When used in the "charger only" position, what is the purpose of the "current limit" knob... :confused:
Thanks in advance!
 
MapisM said:
I'm learning to deal with the just installed Multiplus inverter, with its "digital multi control" panel, and can't understand one thing:
When used in the "charger only" position, what is the purpose of the "current limit" knob... :confused:
Thanks in advance!
Click to expand...

Not a Victron expert, but I would suggest:

1. To allow the charger to be used on batteries who's recharge charge rate is below the maximum output of the charger. This could be more true with lithium based batteries than lead-acid.

2. To allow you to charge at a lower rate to prolong the life of the batteries. Generally, charging below about C/3 or C/4 is thought to give you battery cycle life from you batteries, meaning you can optimise overall system longevity if your application permits.

3. The did because they could.

My betting is no. 3!
 
Thanks folks, I was actually aware that the knob was meant to limit the AC input, because the inverter has a function that they call "power assist", in which if you need say 20A for the peak start of the a/c and the dock only has a 16A supply, by setting the 16A as a limit for the AC input you can get the additional 4A supplied by the inverter and avoid tripping off the dock supply - or at least that's the theory, as I understand it (not tried yet).

That said, DOH! I didn't understand why/when/how that could make sense when using it as a charger only.
But both the example of slowing down the batteries recharge or limiting it temporarily "in favour" of other usages make good sense.

Blimey, this thing is sophisticated!
I already came across it in other boats in the past, but never took the time to dig into it.
I'm just beginning now to realize what sort of control it allows over all onboard electrical systems...
...makes my previous setup look like stone age!
 
markdj said:
Yeah, it's to limit the amps used when charging so if you are on a 16amp shower supply, have just been out sailing and now want to boil the kettle, use toaster or cook, you can turn down the charger and cook without the supply tripping out.
Click to expand...

not completely,

in charge only mode, the amp limit controll works only on your battery charger, (fe when battery's are very low after a long shore power interruption...)
if you switch "on" 230V appliances, through the Victron, totalling over 16A fe, the shore connection will take more than 16A iirc (I'm fairly shure, but don't shoot me if I'm wrong on this)
I'll check it out next week, unless MapisM will find out or find it in the manual by then.

in "invertor" mode,
the Victron will "try" to give the extra missing amps from the battery, on top of the 16amps taken from shore
if the battery's are not powerfull enough the unit goes in protection.
 
Ha Victron, still miss the one I put into my Sunseeker. Once took the boat the a theme park in holland with a marina attached to it . Shore power was limited to 6 amps which was less than the water heater needed. The Victron multiplus saved the day and buffered all the peaks then recharged the batteries later.

Got a genny now and sometimes the itch to upgrade so not sure if I will bother putting one in the targa.
 
BartW said:
in charge only mode, the amp limit controll works only on your battery charger....
Click to expand...

Many thanks B - also for your support, btw: I'd be happy if only a half of the sellers of boat equipment were anywhere near Amptec service levels! :encouragement:).
But actually, my understanding of what markdj said is not different from what you are now specifying.

I mean, he didn't say that in charge mode the knob limits the absorption of onboard utilities, but rather that when you want to use most of the shore power for cooking or whatever, you may wish to spare just a little bit of current for recharging batteries, to avoid tripping off the shore power - and that's what the knob does.
Btw, that is consistent with the behavior I'm experiencing onboard ATM: while connected to the dock, if I rotate the knob till the display shows just a few amps (say 2 or 3), I still can turn everything on, a/c included. it's just the Multiplus that gets less power, hence slowing down the recharge.

Correct me if I'm wrong, but as I understand it, this is what both of you guys are saying.

Guilty as charged for not having RTFM (yet!)... :o :rolleyes:
 
rlw said:
Got a genny now and sometimes the itch to upgrade so not sure if I will bother putting one in the targa.
Click to expand...
Fwiw, according to the (very few, admittedly!) bits and pieces I actually read before discussing the installation with my yard, the "power assist" functionality can work regardless of whether AC is supplied by shore power or genset.
So, if you were thinking to upgrade the genset just to cope with some odd peak demands, the Victron might be a much cheaper alternative.
Though of course it can't supply more than your domestic batteries can cope with... :)

PS: on second thought, is the whole boat that you're thinking to upgrade? If so, I agree that it's not worth fitting the Victron.
Not because it doesn't add value to the boat, but I think you must find a connoisseur to recover your costs...
 
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It's the boat. Made the mistake of going on a Targa 52 for sale last summer on holiday on the Dutch coast. I'll never learn, that how it always starts :)

I would like to have a victron again. Genny is adequate but sometime it would be nice to have an inverter for small loads and a better charger. However due to having a genny on this boat it has not been high on the priority list.

It woth buying the dongle if you are a bit geeky. just to look at the config options in the software. You can config them for different types of batteries/charge settings.
 
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