Shore power issue 2021 R-23

[Stanford]

My 2021 R-23 with lithium ion battery upgrade was found to have a dead house bank and fully charged engine and thruster batteries while stored on the trailer and plugged into shore power. I used a outlet tester to confirm proper wiring, and measured voltage on the female end of shore power cable to be 125 V. However, once plugged into the cockpit receptacle and turning on the shore power breaker and switch, the analog voltage meter on salon AC panel reads only 15 V. And then when I switch on the battery charger, the voltage drops to zero and the reversed polarity light comes on. So I have turned everything off and disconnected the shore power. I would appreciate anyone's advice.

 

[Craig]

It is hard to help you with out knowing what charging systems you have on your boat. Is it all factory components? Do you have a DC to DC charger on your outboard that charges the batteries while underway? Does your charger maintain all the batteries (Start, thruster and house). To start you may want to get a stand alone lithium charger for the house that you could use to keep the house maintained while you trouble shoot

 

[Brian John]

Were your house batteries factory installed? How are they interconnected to the charger? If you are charging in conjunction with your lead acid batteries you may have damaged them though the BMS should protect them.
Is the house battery fused? Have you checked the fuse? How many LI batteries do you have?
What model LI battery do you have? Did the BMS activate to shut off the battery (high heat, over-voltage)
Is your inverter working when on shore power?
Have you checked your ELCI breaker?

Some LI manufacturers have internal fuses on each jar.

I would buy a separate LI charger and try charging them.

 

[Brian John]

Without being able to get on your boat I am just tossing out some ideas hopefully these are helpful ideas.

Do you own a digital multimeter?

With shore power off, and with the battery disconnect off measure voltage at the terminals of each jar. If the voltage is "0" volts that would tell me your BMS shut the battery off for some reason and I would contact the battery manufacturer. My understanding of LI batteries is if the BMS shuts off when the voltage or temperature is outside set parameters and when the voltage or temperature returns to normal the BMS should close and allow the battery to be charged. If the battery voltage is 12 VDC or lower you have totally depleted the battery and the battery needs to be recharged with a proper LI charger.

Who manufactures these batteries?

Some other things to look at, are all connections tight (not sprain a muscle tight but snug), do all the connections look clean no signs of heat or corrosion.

Where are you located?

 

[Rode Trip]

As mentioned earlier, you may have an issue restarting the lithium house bank BMS after it's shut itself down due to low voltage, but that's secondary. Your primary issue is your shore power. Could be cable, connectors, breakers, or adapter if you're using one to go from a 15 amp regular outlet connection to 30 amp shore power connection...You should have an ELCI breaker near the shore power inlet and then another breaker at the main AC panel. You need to be seeing 120 volts at the panel on your analog meter. Battery/charger issue may resolve itself when you fix your shore power issue.

 

[Brian John]

To restart a Li battery that shut down apply charging voltage and the BMS should turn on the battery.

 

[Stanford]

Thanks everyone for your response. Rode Trip got it right, it was a faulty ELCI breaker.