310 DC power issue

[mstenstrom]

I have a 1999 Searay 310 Sundancer. When the water pump is on, it drains power from the batteries, causing the lights dim. I have installed new batteries and all the battery terminals are clean. The only thing I can think of at this time is that the one of the power cables to the battery is faulty, but just a visual inspection hasn't revealed anything. My next move may be to replace them. A lot of work for a guess. Any other ideas would be great!

 

[LifeisGood]

Our lights dim when the pump is pumping but return to normal after.

Do you see the same problem with other DC systems running or is it exclusive to the pump? (vacuflush, radio, spotlight, etc)

 

[mstenstrom]

Derek

The power issues occur when the vacuflush runs, water pump, windlass. The lights dim when the devices are running, but go back to normal afterwards. These really drain the DC power. The generator is running, but the C-charger does not seem to be adding to the DC power

 

[Southpaw II]

When your generator is running, do you have the switch moved for it to feed the house bank?

 

[LifeisGood]

Derek

The power issues occur when the vacuflush runs, water pump, windlass. The lights dim when the devices are running, but go back to normal afterwards. These really drain the DC power. The generator is running, but the C-charger does not seem to be adding to the DC power

You lost me at generator. We don't have one :smt009.

We have been on the hook with refrigerator, vacuflush (multiple times), water pump, and occasional lights many times for 6 hour plus without any battery concerns.

 

[SEARAY290]

Did you check the battery charger output inline fuses? They are usually right by the battery teminal end of the wiring. My 12VDC lights dim when the water pump runs-on battery or ac convertor (charger-shore power or generator).
I think you may want to check the voltage drop and amperage when the pump engages. I guess the pump specifications are available somewhere. As you can guess, an excessive amp. draw with normal flow/pressure indicates a motor or pump problem. High amp draw with reduced flow/pressure may be due to a restricted filter, restricted hose/pipe or an impending pump failure. I have not dis-assembled one of these pumps so I am unfamiliar with the serviceability-may only be serviced as a unit.

 

[mstenstrom]

I visually checked the inline fuses, seem ok. The fuses are the solid paper type, so I will check them with a meter.

I replaced the pump last year, which made the problem better, but it did not eliminate it.

When away from the dock, generator is always on and all AC appliances work fine... TV, Refridg, michrowave.

Batteries always get charged when on shore power. but do not seem to get charged when switched to generator.

Since all major power DC elements dim lights, ( windlass, water pump, vacuflush) seems like a voltage loss somewhere.

Does anyone know how long a power cable should last?
Does anyone know how to verify that the c-charger is working?

 

[aquadancer]

All these accessories draw 12v DC power and it is normal for your lights to dim while there is higher load on your batteries. However, your charger should keep the battery bank charged when you run th genny. I assume you have the charger turned on (AC converter breaker on)?

 

[mstenstrom]

Philly Boater,

I may need to check to make sure the AC converter is on. Is that supposed to be on whnn using shore power or only when the generator is on?

 

[Southpaw II]

Philly Boater,

I may need to check to make sure the AC converter is on. Is that supposed to be on whnn using shore power or only when the generator is on?

Both. It should only be off if there is a concern about boiling the batteries dry. On newer boats, this should not be a concern.

 

[mstenstrom]

Philly boater and southpaw,

I checked the ac converter over the weekend and it is always on. I talked to someone about it and he said it might be a bad relay behind the circuit breaker board. Does anyone know about this? He said if it is there, it should automatically switch when going from shore power to generator.

 

[mstenstrom]

Philly boater and southpaw,

I checked the ac converter over the weekend and it is always on. I talked to someone about it and he said it might be a bad relay behind the circuit breaker board. Does anyone know about this? He said if it is there, it should automatically switch when going from shore power to generator.

 

[Y Knot]

If your boat is set up like mine you have limited 110 on the boat. Probably a couple outlets, fridge, microwave, a light or two. The majority of your lights etc are run on 12volt. Even at the dock if i have a large draw on the batteries the lights dim a little to flush the head. I believe it's just using the batteries and the charger can't keep up with the draw. Just my guess...