Battery Discharge When On Shore Power

[tmakie]

I just installed a Victron Multiplus II with a 300ah Enduro battery. I am connected to shore power and noticed that even when connected to shore power the lithium battery is discharging.

I would have expected when on shore power the Multiplus would always keep the batter topped-off at 100%. It is currently at 97.5% and continuing to discharge.

Is this normal? Will it eventually hit a threshold and then the Multiplus will charge it back up or do i have a battery, multiplus configuration issue?

Todd

[howson]

I just installed a Victron Multiplus II with a 300ah Enduro battery. I am connected to shore power and noticed that even when connected to shore power the lithium battery is discharging.

I would have expected when on shore power the Multiplus would always keep the batter topped-off at 100%. It is currently at 97.5% and continuing to discharge.

Is this normal? Will it eventually hit a threshold and then the Multiplus will charge it back up or do i have a battery, multiplus configuration issue?

Todd

Something is configured wrong, Todd. The battery should stay at 100% when connected to shore power.

Edit: If you can post configuration shots we can figure it out...

[tmakie]

Here is the config pages: I noticed when taking the screen captures that the charger was not set to "lithium" even though i switched it via the MK3 when i completed the initial install. Possibly that was the cause but when I uploaded the new version listed below, it still is discharging. I also changed the current limit to 50amp which is our shore power connection. still discharging.

[Yoda]

I just installed a Victron Multiplus II with a 300ah Enduro battery. I am connected to shore power and noticed that even when connected to shore power the lithium battery is discharging.

I would have expected when on shore power the Multiplus would always keep the batter topped-off at 100%. It is currently at 97.5% and continuing to discharge.

Is this normal? Will it eventually hit a threshold and then the Multiplus will charge it back up or do i have a battery, multiplus configuration issue?

Todd

Todd
This may sound like a dumb question, but what position is the main switch set to on the multiplus. If you have it set to On, try switching to charger only and see if things change. Just a thought to trouble shoot

Howard - howson should the enable battery monitor be checked - wondering if that is needed to trigger the charge?

Keith

[tmakie]

Tried switching to charge only as it was in "on" position and it kept discharging. Could the lithium battery be bad?

[Scott'n'Wendy]

You can put your current limit back where you had it if you like. Your shore power connection is the equivalent of 500 amps at 12vdc.
Seeing as you just installed it, everything is on the table. IMO, because I don't see anything out of the ordinary with config, unless battery monitor should be on, you have an issue with wiring or the Multiplus hardware.
To check the charging, put a meter on the terminals and see if you getting the absorption and float numbers.

[howson]

tmakie

"Overruled by Remote" is checked on the first screen. Assuming you have a Cerbo connected to the system and a screen, what is that limit setting?

What mode does the Cerbo screen show the Multiplus is in?

FYI, on my setup "Enable battery monitor" is checked (enabled).

[tmakie]

The Cerbo GX says in Float. I noticed last night when i switched the Multiplus back to On position the Multi said “low battery” and would not start in On position. Flipped it back to “charge only” and AC from pass through is working and my DC lights, wster heater and furnace are all working.

Smart shunt now says i am at 83% battery and at 13.08 volts. When it gets light out i will put the meter on battery posts and provide a fead ss requested.

Again just seems like some might be off with battery when it says low and wont start in on position yet shunt says 83% and battery volts st 13.08v

Appreciate your ideas

[Scott'n'Wendy]

The Cerbo GX says in Float. I noticed last night when i switched the Multiplus back to On position the Multi said “low battery” and would not start in On position. Flipped it back to “charge only” and AC from pass through is working and my DC lights, wster heater and furnace are all working.

Smart shunt now says i am at 83% battery and at 13.08 volts. When it gets light out i will put the meter on battery posts and provide a fead ss requested.

Again just seems like some might be off with battery when it says low and wont start in on position yet shunt says 83% and battery volts st 13.08v

Appreciate your ideas

Well the Multiplus has to have a way of sensing the battery voltage. If the shunt is providing correct information, it would suggest the issue is with the Multiplus. Wiring or config or faulty. Check the sense wiring from the shunt to multiplus. Maybe loose or incorrectly wired.

[Jimmer]

The Multiplus is not charging, and all of your settings seem to be correct. Assuming there is not any defective hardware, here two theories:

1) The Multiplus is not connected to your battery. With shore power disconnected, take a reading of the DC terminals on the Multiplus to assure that the Multiplus is connected to a working battery and the meter is showing 13+ volts.

2) The Multiplus is not connected to the smart shunt, so the Multiplus doesn't know the true battery voltage. On my setup, I do not have the "Enable Battery Monitor" checked and the system works fine as it's getting battery info from the smart shunt. However, as Howson recommended, try changing the setup so that the battery monitoring of the Multiplus is enabled.

If no one of that works, post a picture of the main screen of Touch50 display so we can see if anything looks off.

[tmakie]

Attached the wiring pic below. I cant imagine it is a bad multiplus as this is the 2nd one as the previous one was acting similarly where it would not start in On position.

the wiring simply goes from battery through shunt for neg to lynx 1000 to multiplus. And similar on pos but does not connect to shunt obviously.


just keeps me pointing back to battery. Is it possible the BMS is sending incorrect info and stopping access for absorption. The pic does not show it but i have the solar controller connected to lynx 1000 and when watts of solar are being passed through controller they never charge battery either but will pass to multiplus rv AC loads periodically.

i know the lynx 1000 is just a glorified neg / pos buss with fuses so I don’t believe that would be the issue.

[tmakie]

Here is the cerbo gx pic of current state.

[Jimmer]

1. It seems strange that the picture of your Cerbo GX shows for the AC you have one input at 72 watts, and the other leg at minus 21 watts. That is strange. Don't know what it means, but it might be a clue that something is not working right.

2. Thanks for the picture of your setup. Looks very nice. But I still think it's worth taking a voltage reading with a meter at the DC terminals of your Multiplus when the AC power is turned off. With mysterious behavior, you got to look at every possibility. For example, if the fuse leading to your multiplus from the battery is blown or defective, that could explain what is happening.

[Scott'n'Wendy]

howson Appears to me that the battery and Multiplus connections are not correct.
Battery connected to where you have the multiplus, and multi on the end....Disclaimer..I don't have one but that's the way it looks to me it should be wired.
Being the second multiplus doing the same thing really points to a wiring or sensing problem.
IMO, nothing points to the battery, the smart shunt is showing normal numbers. But meter readings at the battery will help

[howson]

Scott'n'Wendy -- I believe you're correct.

tmakie -- based on what I can see in the pictures it appears the -12vDC wiring from the battery to the Multiplus is bypassing the Smart Shunt. Here's how I see it wired:


If what I'm seeing is correct, this is how it should be wired:


I'd appreciate an assist and review by ncitro Country Campers Scott'n'Wendy Jimmer and anyone else that has installed a similar system.

Howard