Bait tank batt - timer switch vs reverse polarity

[Sdspeed]

Originally Posted by Dave k

Thanks guys. Looks like 6v or a valve are the way to go. Back to the drawing board.

Thanks again.

If your running a single 12v battery you can always put a VW 6v line drop in prior to the pump. we use them on VW restorations so that you can keep the
6 volt wiper motor and yet run a 12 volt electrical system for the rest of the car.

[GregAndrew]

If your concern is that the 12v battery will pump too much water then:
A timer switch is not really going to help (just cycle between too much and none at all).
A 6v battery will help.
Anything restricting the flow will help (valves, spray heads etc.).
Reversing polarity will help (how much depends on your impeller type).

If your concern is that the battery will drain too fast then:
A timer switch will help.
A new 6v battery with more amps will help.
Flow restriction will not help.
Reversing the polarity will not help.

[bus kid]

Originally Posted by Sdspeed

If your running a single 12v battery you can always put a VW 6v line drop in prior to the pump. we use them on VW restorations so that you can keep the
6 volt wiper motor and yet run a 12 volt electrical system for the rest of the car.

who is "we"?

The voltage dropping resistors are not water resistant though.

http://www.empius.com/vwcatalog/2013/279.html

[tomahawk]

I am not sure how the bilge pumps are rated but I used to be heavily into saltwater aquariums. Using a valve to reduce the flow adds back pressure to the pumps and can significantly shorten their life. Aquarium pumps usually have a maximum head height to limit the back pressure (usually in inches of water). 6V is a better option IMO.