Battery Bank on the hard

[Jfrano]

So after 1 week on the trailer, disconnected from
Shore power. Having pulled the fuses except the 2 for the bilge, I’m seeing
Bank 1 13.32v
Bank 2 11.82v
Bank 3 13.30v

So Bank 1 and 3 seem high and 2 seems low.
Plugged in shore power while I’m at marina for a few
Hours .
Any thoughts
Thanks
Joe

 

[Tippetknot]

What model and year. Is bank 2 your house bank?


Sent from my iPhone using Tapatalk

 

[Jfrano]

It’s a 2017 29CB

Bank 2 is the engine battery and 3 is the truster
Battery.

 

[scross]

According to my discharge table, 11.8 volts is fully discharged. If this happens repeatedly it will likely kill your battery. If it’s not dead already, which would explain its inability to hold a charge for very long. I’d recommend testing the engine battery. Or, if it’s not connected to the bilge pumps, just charging it and disconnecting all connections to both terminals.

 

[knotflying]

Since it was a week I will assume that you did not leave the engine key in the on position. Had that happened the battery would have been much lower then that. You should make sure that there are no other items on your engine battery that may be drawing power. How old is your battery? Next step would be to charge the battery up to full and let it rest for about 30 minutes and then do a load test. Sometimes load tests pass, but the battery is not good so the test could be inconclusive. If there are no parasitic draws then chances are you could have a bad battery.

 

[BB marine]

So after 1 week on the trailer, disconnected from
Shore power. Having pulled the fuses except the 2 for the bilge, I’m seeing
Bank 1 13.32v
Bank 2 11.82v
Bank 3 13.30v

So Bank 1 and 3 seem high and 2 seems low.
Plugged in shore power while I’m at marina for a few
Hours .
Any thoughts
Thanks
Joe

The Voltage readings do not seem right. Something else is charging Bank 1 and Bank 3 (Solar panel) ? If there is no charge going to a battery bank the batteries in a full charge state should be 12.7 in a resting state with no charger after the batteries stabilize ( couple hours). 13.32 and 13.3 Volts would indicate a charging source is available. The next question that I would ask is- Are the ACR's functioning properly. If a battery bank is @ 13V or higher for more than 90 seconds the ACR close and parallel the banks together. The ACR are Bi-directional so it doesn't matter which bank is over 13.0V as long as the other banks are @ 11 V or higher the ACR will close until the all battery voltages drop to 12.7V.

What type of Meter are you using to check the voltages?
Are the green lights on ACR ?
Is there a Solar panel active charging the battery banks?
Did you check the engine battery voltage at the battery with a VOA meter? It may be closer to 11V and the ACR has locked the engine battery out.The house and thruster bank is charged through a Solar panel if available.
My Guess is the engine battery is marginal condition and needs to be replaced. Without a full troubleshooting of the system this is just a Guess.

A fully charged battery bank at a resting state ( no charger) should maintain a Voltage of 12.7 to 12.5V for months without a charge if the batteries are in good condition.

 

[knotflying]

Good catch Brian. And if there is a solar panel it looks like the thruster is connected and not the engine battery.

 

[Jfrano]

So there is a solar panel connected. Which is why it’s confusing.
Should be charging bank 1&2. Yet 1&3 look like their being charged, in this instance.
Looks like something is drawing on bank 2, the engine, but I don’t think there’s anything else
On that bank.

Was at the boat today and all three banks were at the 13.3 to 13.4 volt range (no shore power connected). Which was good to see that all three held the charge. However when I connected to shore power, the inverter complained with a fault that the batteries were overcharged. I reset the inverter/charger and it didn’t complain any more.

 

[Red Raven]

Perhaps the propane safety solenoid was on drawing current from the engine battery greater than what the solar panel was producing (cloudy days?). Check that it is off.

Curt

 

[knotflying]

Electrical issues can be complex and time consuming to figure out. There are many components working together and tied together. The ACR's open and close depending on what needs charging and will lock out when a specific battery gets low. If this problem persists you should put together a methodical plan of action starting with the simplest thing and progress from there. Start with the engine battery. Make sure it is fully charged and then disconnect everything going to it. Let it rest for a day and then check the voltage. If that checks out okay then do a load test and see what you get. If all is good then examine what is attached to the battery. It should only be engine items and the solar lead. Keep the solar lead off and disconnect the ACR and see what happens. If all is okay then re-install the solar lead and ACR.