Dead Engine Battery Conundrum

[GZigmont]

Have a new to us 2021 R-31 CB with a warranty replaced engine with about 75 total hours on the new engine. I replaced the engine and thruster batteries about three weeks ago with X2 combo batteries from Batteries Plus: Group 31 1150 CCA combo batteries, as the originals would not hold a charge. Batteries have been fully charged and maintained on shore power, except for short outings.

Yesterday we motored to a cove about 15 minutes from our marina on the CT River and picked up a mooring for approximately three hours. Once we were secure on the mooring, I shut off the engine, the ignition and turned off the engine and both thruster battery switches. Although the following would only draw from the house bank, I turned off the inverter, the wine cooler, and the Garmin electronics. The only juice used- and only from the house bank, was for the Fusion stereo, the water pump and toilet.

Upon getting ready to leave the mooring, I turned on the engine and thruster batteries, as well as the Garmin electronics and then hit the ignition switch for the D-4. A brief blip of graphics on the Volvo Penta display, and then it went dead. Start switch was inoperable. I went over the volt meter on the panel, flipped it to engine and it read 0 volts. I paralleled the batteries to get the engine started and it was an incident free 15 minute ride home.

Upon getting to the dock and turning off the engine, the engine battery meter read approximately 13 volts after only the fifteen minute ride. Restarted the engine and it was fine. Turned off the ignition, the engine and thruster batteries. I kept the shore power unhooked for a little while and monitored the engine battery voltage and saw no drop.

Anyone have any ideas? I’m stumped. Full disclosure though, this boat has had some other wiring anomalies on the AC side from the factory. I also found that the automatic side of the aft bilge pup was not working and had blown the fuse. This side of the pump is wired to the engine battery. I tested the pump using another power source and it worked fine. The factory wiring apparently had an actual short, which caused the fuse to blow. I cut the positive at both ends and ran a new clean wire to the pump. The original wire which is part of the harness is not connected to anything at either end, and even if it was shorted to a ground, it’s not connected to anything positive. I don’t think that there is a parasitic current draw from this circuit. I also replaced the solenoid for the propane, which memory tells me is also connected to the engine battery. That system is working properly, so I don’t think there is a current draw on the engine battery from this either.

Finally, I have noticed that the Volvo ignition sporadically turns itself on many times (not all) when the engine battery switch is turned on – similar to how one may set the Garmin electronics. I looked though all of the screens on the Volvo display and read through the manual and couldn’t find such a setting. I’m thinking there is something going on here that might be draining current.

The only thing I can think of doing next is to go through all of the positive leads to the engine battery, one by one and look to see if something is drawing amps even when the battery switch is off. I’m thinking that whatever is going on here is what killed the first battery. What say you?

 

[glider4]

Just some thoughts:
My experience with the X2 batteries has been good. Unlikely that a newer battery would be damaged internally but possible.
Battery voltage reading zero then fully/mostly charging after only 15 minutes suggests that it’s a loose cable or wire connection (or corrosion) that’s a problem, not a sustained current draw off the engine battery. I’d be checking both positive and ground connections for possible loose cable situation.
If it were a draw draining the battery I’d think you would be reading at least some residual voltage after 3 hours at anchor but not zero volts.
Obviously not a breaker issue but it might be a bad rotary switch.
Did you test the voltage directly at the battery terminals with a volt meter when it read zero volts? That would have helped understand the “is it a bad battery” or “do I have a very large current draw down on this battery” questions.

 

[AGLyme]

Sounds like you moored in Hamburg Cove… beautiful place.

Coincidently, just this morning my Grand Banks owner pal has a similar situation to yours. A retired boat dealer friend of his went on his boat and found the culprit… The negative nut was loose on the starter. Evidently when the starter button was depressed, it would sometimes start… and sometimes not because the wire “jumps” into position to start, or it jumped out of position and didn’t start.

The nut was tightened and all was fixed.

It would make sense that the fault lay in a mechanical disconnect somewhere instead of the charging system.

I too had the same issue with my rear Rule bilge pump. Happy to meet up one day and compare notes on that. I’m at the Old Lyme Marina.

 

[GZigmont]

Just some thoughts:
My experience with the X2 batteries has been good. Unlikely that a newer battery would be damaged internally but possible.
Battery voltage reading zero then fully/mostly charging after only 15 minutes suggests that it’s a loose cable or wire connection (or corrosion) that’s a problem, not a sustained current draw off the engine battery. I’d be checking both positive and ground connections for possible loose cable situation.
If it were a draw draining the battery I’d think you would be reading at least some residual voltage after 3 hours at anchor but not zero volts.
Obviously not a breaker issue but it might be a bad rotary switch.
Did you test the voltage directly at the battery terminals with a volt meter when it read zero volts? That would have helped understand the “is it a bad battery” or “do I have a very large current draw down on this battery” questions.

No I didn’t do any testing at all. That was just at the meter on the panel. We had guests on board, so I will be going through everything in a couple of days.

 

[CaptT]

I'm with glider 4 on this one. I had almost the same thing happen to me during a fuel stop,. The meter showed zero volts but when I was back in my slip I used my volt-ohm meter directly on the post and wallah 12.8 volts! Dielectric grease and tight cables fixed the problem for good.

 

[GZigmont]

Okay folks, I may have solved the battery mystery and if I have, I can take credit for messing something up. The two X2 batteries I installed have dual terminals - SAE as well as 3/8 and 5/16 threaded terminals. Both types of terminals have a nut at the bottom and can be removed. Our boats use the threaded terminals.

While I was installing the batteries, I became concerned that the positive SAE terminals might be a hazard as it was difficult to cover the exposed unused terminal with the terminal boot. So seeing that I could get a wrench on the SAE terminal, I figured that I would remove it and remove the hazard. But, before I did so, I sought out advice from one of the mechanics at my marina and asked him If he know about that style of battery with the dual terminals and if I could remove the SAE. His reply was “sure.” I already had the batteries in place, so I crawled in and started to remove the SAE terminal. Halfway through, I decided not to remove the SAE, because the entire assembly that housed both terminals was becoming loose. I re tightened the SAE terminal, but because of the awkward angle I was working at inside the lazarette, I apparently did not get it tight enough.

I crawled back in there today and found that there was some play in the assembly for the terminals on the positive side of the engine battery, which caused a lack of continuity when moved. I uninstalled the battery, inspected it and tightened the SAE properly and then reinstalled and reconnected. All appears fine. I’ll let you all know if this ends up not being the cause of my problem, but my money is on this.

 

[glider4]

Rule of thumb I have when I work on anything.
If something was working just fine before I started the project and now it’s not working the first step it to look at everything I touched to see if/where I messed up. Typically that solves 90% or more of the problems.
More difficult task is trying to find a new problem’s source right after a professional mechanic has worked on the boat.

 

[GZigmont]

Rule of thumb I have when I work on anything.
If something was working just fine before I started the project and now it’s not working the first step it to look at everything I touched to see if/where I messed up. Typically that solves 90% or more of the problems.
More difficult task is trying to find a new problem’s source right after a professional mechanic has worked on the boat.

Agreed. But the problem is that it wasn’t working fine before I installed the batteries. I had almost the same situation before replacing the batteries. Dealer claimed to have load tested the batteries that came on the boat, yet the start battery would die soon after being disconnected from shore power, started once and then turned off for say a fuel stop. There were many other factors, such as that, that contributed to my mystery. Only time will tell if this was actually the root of the problem.