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jordan-de-geus avatar image
jordan-de-geus asked

Multiplus Compact charging not at 80amps?

Hey all,


I've had the multiplus compact for a year or so now. It is onboard a sailboat which is used daily as an inverter and is disconnected from shore power 99% of the time. Last winter we were able to charge @ 80amps. Summer came around and we don't need to run our generator or plug into the dock as solar covers 100% of our needs. Well winter is here, we need to run our generator every couple days to charge the batteries.

Since Nov 3rd when we first needed to fire up the generator, i have started to notice the charger is only putting out around 60-70amps. I thought this was weird intially, thinking maybe i mis-read the voltage and we actually weren't as low as i thought we were. Well since that point, we've ran the generator 5 times, plugged into a dock once, and am currently running the generator as we were around 11.8v(60-70% discharge for our firefly battery bank). Well i assumed due to drawing the bank down this low, I would have assumed to see roughly 80 amps coming in via the generator(2200 watt generator). Alas we only are seeing around 68amps at the high end of things.


Does anyone have any ideas or suggestions as to why this would be? I have the inverter set to 30amps(generally set it to 18.5amps but figured lets rule this possibility out).

battery charging
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4 Answers
Jason - UK avatar image
Jason - UK answered ·

@Jordan de Geus What exact Multiplus compact unit do you have?

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jordan-de-geus avatar image jordan-de-geus commented ·

Part number: VIC CMP122200100

Its the 2000VA MultiPlus Compact. That link above should bring you to the unit i purchased from Fisheries Supply.

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jordan-de-geus avatar image
jordan-de-geus answered ·

One thing to note - i have 2 house banks, located in different spaces - both banks have temp sensors on them. My initial thought after posting was "maybe its temp compensating", though the banks are 16 deg C and 14 deg C, which i would assume would ONLY affect the Bulk/Absorb/Float voltage levels for the charging states?

I did just fire up my primary diesel engine for about 45 minutes as my firefly bank when drawn down to the 40-20% remaining levels needs to have a charge rate of .4C on the bank - roughly 170amps(40-45amps per battery in the bank). With the engine running + the generator i was able to push 175amps into the bank, which I would have assumed IF the Victron was working correctly, should be pushing its max charging capacity prior to the alternator being able to push 100+ amps into the bank.


Maybe i'm missing something here, but to me it seems like the inverter/charger is self limiting itself & i know its not the generator as I'm able to easily load it up to 2200w by passing my water heater to it.

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jordan-de-geus avatar image
jordan-de-geus answered ·

Bumping for any suggestions

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kevgermany avatar image
kevgermany answered ·

Assuming the AC in is not limiting the multi (as appears to be the case) and charge parameters correct for your batteries, output to the batteries will be limited by batteries, wiring and temperature of the multi.

There's also an AC current in limit setting in the multi which would affect charge rate.

Are you measuring charge current at the batteries, or at the multi? Could be other loads taking current before the battery gets its input.

It would help to know charge settings, battery type/recommended charge voltages, input current limit on the multi and voltage at the batteries with and without the diesel running.

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