reverse polarity light on, only when inverting?

[NWboater2]

Hi all here's one I haven't seen. This summer we had new house batteries installed (4x4D Lifetime AGMs) along with a Victron touch screen, cerbo gx, bmv monitor and smart shunt. Seems to work great, haven't been below 79% and have been back up to 100% every day, except one.

Sunday we left the dock with batts 100% and went for a spin. Noticed that the Touch was not showing "charging" underway, and instead showed negative watts going into the batts. Also saw that my wife had turned on Victron Multiplus Inverter, and that the reverse polarity light was on, on the blue seas AC panel. Turned off inverter, light went out. Touch still didn't say "charging" but the batts never went below 100% all day. Back at the dock, engine off, shorepower not yet connected, inverting still showed reverse polarity? Hooked up shore power, Touch showed "charging" as normal and RP light was off. AC outlets worked while inverting.

I don't think its related but the same guy (from S3 in Seattle, happy with them) recently replaced a failed water temp switch on NL 673 generator....(that failure caused the one day we did not recharge to 100%, on the hook).

I have a call into S3, but what do you guys think could be the cause of this? The Touch is new enough that I'm not absolutely positive what it "normally" said underway but I'm pretty sure it showed "charging," even when inverting. I also have to admit I cannot say for sure that the reverse polarity light was not on since the initial work, but I am pretty sure the display screen was different underway. No other obvious symptoms......thanks for any advice!

 

[NWboater2]

Perhaps I should add I have an older Leece 220 amp alternator with Balmar AR4[?] external regulator....but the RP light is on when inverting, even with engine off....S3 has not worked on alt or reg.

 

[Bmarler]

Only thing I have to say is to be careful with that inverter till you get it sorted.
When I bought my current boat, the po had an inverter installed improperly. Hot and neutral swapped on the terminal strip. This energized the case of the inverter with 120 volts. I got bit hard when I had one arm against the dc negative buss bar and then grabbed the inverter case.
Reverse polarity needs to be found asap. Don’t use the inverter till you find the issue.

 

[SteveK]

RP is AC and charging is DC. The shunt reading -negative charge, yes is telling you more DC is being used than being charged (that assumes you are charging) or it is just discharging.
RP on AC light could be from attaching a neutral to the wrong neutral buss, inverter loads should have their own neutral buss or you will get bleed between them.
What was done since there was not a RP light?

 

[NWboater2]

S3 recently added the smart shunt, BMV 712, cerbo GX and Touch 70 (along w 4 new AGMs with mostly new wiring) to my existing system which includes a Victron Multiplus 12 /3000/120 and the older alt and reg. They also have replaced failed water temp switch on the NL 673 but I have not run that recently.

The new cerbo talks to the inverter so they tapped into it somehow but i dont think they re-wired that end. here is a screen shot of what its doing now....on 30 amp shorepower...thanks for any input