CO detectors sounding alarm

[tomschauer]

Wow, sounds like a PIA problem. Low Flyer, you have all new batteries and a new charger and still cooking batteries. Sounds like something is putting a fault current on the batteries. First thing is do you have a DC to AC inverter? If so, its most likely the problem. If not,does your new charger show amps and volts? I believe I would disconnect everything from the batteries and run temp wires from the charger to the batteries and see if they top off and the charger shuts down. If so, start connecting loads. start with just one battery and with all breakers off, see if it holds charge / voltage and charger is happy. If not look at the loads not fed from your 12 breaker panel, such as your windless, bilge pumps and shower sumps. If any of these are locked up, faulted or just continue to run, they can draw some pretty good amperage. Its not common, but sometimes breakers can fail in the closed positon and not trip under load. Another uncommon problem is the alternator(s) faulting. Disconnect the red battery lead from each alternator if you have to go this far.

[Viper]

If you have a battery selector switch, and you left it on "BOTH" or "ALL" you basically hooked up a new battery (#1) to a marginal or bad battery (2). This will typically cause the older/poor battery to take down the new one or boil it which are now both in the same bank (that's a no no).

Check your connections. They must be tight and clean. Check them at the batteries, at the charger, and behind the battery selector switches if applicable. If the charge wires go through breakers, check the connections there too. If the ground wire from the charger goes to a ground point other than the battery such as the engine block, ensure the ground connections at the blocks are clean and tight as well.

Ensure the charger is set to the correct battery type ie; flooded, AGM, etc.

If your battery cable or charge wire insulation is discoloured (usually close to the terminal lugs/connectors), it has overheated and could be causing a high resistance.

Do you have a diode battery isolator? If so, the charger should not be connected to it (have seen this a few times). You could use the isolator as a connection point but it must be connected on the battery side of the isolator, not the alternator side.

All the above will boil batteries.

[Low Flyer]

Thank you guys for the quick replies.

bud37, I thought the same thing about the fridge and will pull it out and see what is connected to what. The refrigerator was replaced in 2011 so it is not that old. I will also check for a GFCI fault causing the fridge to stay connected to battery power all the time.

tomschauer, No inverter on the boat. The new battery charger is not connected through the individual 3 bank circuit breakers yet. I do have power and ground wired to the original circuit breaker for the battery charger. So each battery is connected directly to the battery it is charging. I have not turned off the DC circuit breaker panel at the helm but will try that this week also. Good idea disconnecting the batteries from everything on the boat except the charger to see if they will charge.
I did load test the batteries and they are all showing good on the load meter.

Viper, I did have the Perko set to BOTH and like you said, that probably killed the new battery but then replaced both batteries again. The new charger is supposed to automatically check, analyze, charge and maintain each individual battery but I realize that even a new piece of equipment can be bad. The charger will also work with multiple mixed battery types and charge accordingly. I have checked and cleaned connections, grounding points and disconnected and tested loads on items that are always connected to the battery bus even with the Perko selected OFF. The fridge is one of the things I hadn't thought about until I started searching the Forum for answers. No diode battery isolator that I know of.

My buddy brought up a point that might take the new DC system out of the equation..... Whatever is pulling down the batteries and forcing the charger to be in a constant charge mode was what prompted the new batteries and charger. He thinks it is a existing problem that was not corrected with the new DC system components. That also makes sense to me but I have to try all of your suggestions until I find the culprit.

As a side note, the only thing that has stopped working since the problems began was the starboard fuel sending unit. Also, am I correct that stray voltage and galvanic corrosion could not be drawing power from the DC system causing a constant charging of the batteries?

Thanks for the help.... keep it coming.

[bud37]

Here is a link to some info regarding your stray question......one other thing is the radio memory that can pull up to 10 amps if the original gone bad.........
http://www.passagemaker.com/articles/te ... nsformers/
https://gilwellbear.wordpress.com/categ ... -isolator/

[Viper]

Source of the post.... I did have the Perko set to BOTH...then replaced both batteries again. The new charger is supposed to automatically check, analyze, charge and maintain each individual battery....

The charger will not maintain each individual bank separately if you have the selector switch on BOTH. By doing that, you're combining the two banks into one. The charger will see this as one battery, not 2 or 3 individual ones. Further, if one battery is a deep cycle and the other is a starting battery, by setting to BOTH, you're combining and charging in the same bank, two dissimilar battery types.....a no no.

Check and ensure there are no bare wires or connections sitting in bilge water, usually the case with bilge pump/float switch wiring. This will cause power drains.

[mjk1040]

I do not believe it matters on that year and model Carver what position the battery switch is in when the charger is working. I believe the charger is wired to the batteries at the battery selector switch directly to each battery. Our 355 has a selector switch for the 2 engine batteries and a selector switch for the jenny battery. Mike

[Viper]

Doesn't matter how or where the charger is wired. If you parallel two separate banks together with the switch ("BOTH"), the charger will see them as one battery.

[Midnight Sun]

My boat has factory wired on/off switches only, no manual combining is possible such as selecting both. Was this implemented later or are most like this? There are a couple of factory isolators however I have not taken the time to explore what they control and how they function yet.

[Viper]

OEMs seem to be bouncing back and forth between multi-bank selector switches and ON/OFF switches. I've seen the same OEM use both depending on the model even in the same year. The movement though is moving away from the multi-bank switch, they are not a good idea. While I like that your boat doesn't have the multi-bank switch, you didn't mention anything about an ability to combine banks in case of an emergency like starting your engines if one or both engine batteries fail. Every boat should have the ability to do this but not with a multi-bank switch. There are better ways. If you don't have this ability, you should consider the option. We can help with that.

Typically isolators are used to charge multiple banks from one or two alternators. Since the typical charger is capable of charging multiple banks while maintaining bank isolation, you don't need an isolator for them. Having said that, you can incorporate an isolator with your charger if you add an additional battery bank but have no spare charging legs left on the charger. Caution is required here though to ensure this is done properly. A good example would be a 3 bank charger hooked up to each of two isolated engine batteries, and the 3rd leg to the house bank. If you decide to add an additional isolated bank dedicated to a thruster or sensitive electronics for example, a practice that is becoming more popular, you'd need a way to charge the fourth bank while still maintaining isolation from the others. You can change the charger to a new four bank unit, or purchase an additional charger, or add an isolator or ACR to one of the charging legs for the forth bank.

[mjk1040]

Source of the post Doesn't matter how or where the charger is wired. If you parallel two separate banks together with the switch ("BOTH"), the charger will see them as one battery.

Viper;
Thought I saw 3 separate feeds coming off the OEM ACtoDC charger to the three OEM batteries in this year and model Carver, leading me to believe that they were all being treated independently. I'll have to do some diagram research this season with the paperwork on the boat on this. Our boat has alternators on each engine. I assume each engine has its own battery. If I run on just one battery with both engines running only that engines battery registers on the dash volt meter. When I'm running in the both position on the battery selector switch, both dash volt meters register? Thus leading me to believe they are independent of each other? Mike