New Batteries are Dead and Won't Charge

Hi,

I posted the below in the official 380 thread and all I got was sympathies. I'll try to summarize to see if anyone knows where I should start...

Configuration:
- 2000 380 DA with 2 port batteries (engine) and 2 starboard batteries that are new (engine and house)
Symptoms:
- On shore power, all is normal
- De-energizing shore power everything is dead... zero volts
Other information:
- Prior to putting in new batteries, used the cross-over to start the starboard engine and one of the old starboard batteries exploded

Going down below now with a multi-tester to see if I can determine if charger is charging both banks.

Any ideas/advice would be appreciated. I don't feel safe going to sea under these conditions.

Thanks.

~~~~~~~~~~~~~~~~

Hi all. I am really frustrated... please read to the end so you understand the facts and I really hope someone can help me.

My starboard side batteries keep needing replacing. I paid the marina where we wintered to remove all the batteries and place the in dry storage, but they didn't.

We launched a couple of weeks ago and the starboard side was dead as was the generator. I used the cross-over switch last weekend to start the starboard side engine and one of the batteries exploded - bigley (is that a word?). I spent the day (90 degrees) in the bilge removing the old batteries and cleaning up acid, then installed 3 new marine batteries.

So proud of myself now, I decided we should go for a cruise. I went to turn off the shore power. As soon as I did the radio and other house systems shut down. My brand new batteries won't even run a radio. Checking the voltage on the panel, the starboard side read about 3 volts.

I started the engines as a diagnostic (using the battery crossover) and found that the voltage for the starboard side fluctuated dramatically even though the alternator is brand new (port held steady at around 13 volts). Energizing the shore power once again everything was normal.

Has anyone else experienced this problem? Any suggestions as to how to troubleshoot would be appreciated.

Thanks,

Michael.

More information...

Batteries are in fact not dead. They measure 14 volts with the solenoid energized or not (not charging). The solenoid operates fine. Charger is sending 12 volts to the solenoid.

My problem therefore must be north of the batteries. Why would the house systems show zero volts when off of shore power?

Batteries should NOT read 14V without a charge being applied (whether battery charger or alternator).

I'd first start by completely disconnecting each battery and use a volt meter directly at the battery (to avoid erroneous readings at the dash). A load test would be a smart thing to do here, as well.

If all is good there, the next thing that pops into my head is that the batteries are hooked up wrong.

Until both of the those things are checked and verified, I don't think there's much use in further diagnosis since it may just be guessing and could very well be wrong.

I would get a schematic for your boat and review how the batteries are hooked up, how they connect to the battery switches, and the isolator. Seems something is connected wrong, or broke. Are we sure both battery switches are on?

The generator battery most likely only gets charged by your onboard battery charger - so if it was dead too - you may have a problem with the charger. Some chargers have fuses integrated.

Not sure if this is your model..
https://s3.amazonaws.com/srweb-pvt-...-manuals/2001_380 Aft Cabin_380_Aft_Cabin.pdf

You mention solenoid - and charging - in the same sentence - which is strange. Are you referring to the emergency start solenoid? You should not have to energize that solenoid at all when testing or charging.

Jumping to the other end since you sound like you know what's up: This sounds like either a bad convertor/charger or a bad isolator.

The convertor should produce 13-14.5 volts when connected and on. The isolator should show the same voltage going in and going out.

A completely dead battery gasses off CO2 and when you apply charging voltage to one, it can explode.

It's the hydrogen not CO2 that's explosive.

If you can take a few pictures and post them on how everything is wired up.

Your battery(s) are not connected to the engines charging system. Thats why the alt is running wild. On shore power the charger is supplying the power , not the battery(s)

Sounds like you missed a connection or put one in the wrong spot when reinstalling batteries.

Thanks for the replies.

Weird stuff going on...

Voltage readings at batteries are around 14 volts. Reading at power-in and load sides of port and starboard solenoids is 14v when energized (shore power on). De-energizing the port side reads 14v in and 0v out. De-energizing the starboard side reads 14v in and 1.5v out.

When off of shore power, I'm reading good voltage at the batteries, 13v input on port solenoid, but only 5v input on the starboard side solenoid. Likewise only 5v at positive terminal of starboard side starter motor.

I'm thinking a bad starboard side solenoid or a short somewhere that's back-feeding the starboard side.

Any ideas?

Thanks again.