Moderated Discussion Areas
  ContinuousWave: Small Boat Electrical
  Battery Drain

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Battery Drain
Laurak posted 08-27-2012 08:05 PM ET (US)   Profile for Laurak   Send Email to Laurak  
I have a 2000 23 Conquest. I have a drain going on with number-one battery that I can't figure out. The bilge pump is directly wired to my number-one battery and I thought the problem was a stuck float switch. However, that is not the problem. I replaced the float switch; it is working properly, and the battery still ends up dead. The battery is new and is not defective. I would appreciate any suggestions you may have as to the cause and remedy to my problem. Thanks for your attenton to my request.


DVollrath posted 08-27-2012 08:27 PM ET (US)     Profile for DVollrath  Send Email to DVollrath     
How long does it take to drain the battery after it is fully charged? If it is a low enough rate of discharge (<10A or your meter limit) and it is not intermittent, then you could use the current function of your volt meter. Put the meter inline with the positive lead of your battery (connect by following the device's instructions), and see what the draw is. Start removing fuses and/or loads one at a time. Hopefully this will identify the culprit, or at least give more clues to direct the next step.

Good luck.


jimh posted 08-27-2012 11:16 PM ET (US)     Profile for jimh  Send Email to jimh     
If a boat battery is persistently drained of its electrical charge when the primary power distribution switch is set to OFF, and if the directly connected loads have been checked and found not to be the source of the current drain, then the most reasonable source must be some parasitic current drain due to a leakage path. A leakage path could occur between the battery terminals themselves, or a leakage path could occur in the primary power distribution wiring, or a leakage path could occur in the primary power switch.
jimh posted 08-27-2012 11:18 PM ET (US)     Profile for jimh  Send Email to jimh     
Also, do not overlook the outboard engine. If the outboard engine is connected directly to a battery the parasitic current drain could be occurring in the outboard engine.
swist posted 08-28-2012 08:47 AM ET (US)     Profile for swist  Send Email to swist     
Does your boat have a off-1-2-both or some other type of battery switch? If so, you didn't say what settings the problem occurs under. If it's off, the only possible places to look are the switch, the battery itself, the wiring between them, or the bilge pump.
frontier posted 08-28-2012 07:07 PM ET (US)     Profile for frontier  Send Email to frontier     
We recently had a battery drain problem in our Whaler.
Turns out it was the stereo system memory.
I put in a on-off toggle switch just for the stereo.
Problem solved.
jimh posted 08-28-2012 10:57 PM ET (US)     Profile for jimh  Send Email to jimh     
It could be the grow-light for the tomato plants on the stern rail, too.
Bella con23 posted 08-30-2012 07:57 AM ET (US)     Profile for Bella con23  Send Email to Bella con23     
I had a problem with keeping my #1 battery charged on my '99 Conquest as well. The problem was twofold.

My bilge switch was mounted directly to the inside hull and was too low for the pump to remove the water necessary to trip the float switch off. This would cause the pump to run continuously.

I raised the switch on a 3"x3"x3/4" piece of whaler board and that solve that problem.

The second problem turned out to be the dual battery charger. Battery #1 charger circuit must have had a bad diode because as soon as I removed shore power to the charger it would start drawing from the #1 battery.

A cheap multi-meter and patience will find your problem.

jimh posted 08-30-2012 08:47 AM ET (US)     Profile for jimh  Send Email to jimh     
Bella--thank you for that very interesting observation about the poorly designed system for the sump pump and float switch. As you observed it is possible to create a system in which once the water level rises to the point of activating the pump via the float switch the system cannot reach the shut-off state. This could be a cause of the battery drain that might not be apparent from just a cursory examination of the the float switch's operation. The notion that you had the same boat and had a problem with the same battery makes your advice especially cogent. Thanks again.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.