Moderated Discussion Areas
  ContinuousWave: Small Boat Electrical
  Battery discharge due to Electronics

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

Author Topic:   Battery discharge due to Electronics
BermyBoater posted 05-28-2007 08:50 PM ET (US)   Profile for BermyBoater   Send Email to BermyBoater  
Can anyone shed light on the expected discharge rate of batteries due to boat electronics that are in the 'off' state but still energised?

I have recently purchased a new Ventura 210 with Merc Verado 225. Boat has dual batteries with switch. It appears that all the electronics (Navman fish finder, GPS, VHF & Clarion Stereo) are energised when either/both batteries are on. In other words, they can be turned on without having to turn on the accessory switch or the ignition switch accessory position. The first weekend I left the boat with the battery switch in the 'all' position as advised by the dealer & next week the batteries were totally flat. Every weekend since, I have been cycling in a fresh battery ( all batteries are the same model ) and the following week everything is dead again. Since the old boat had no modern electronics - just a VHF that had a proper knob that switched off the unit - I have no idea what to expect. Should the battery switch be turned off after using the boat, leaving just the bilge pump connected?

Any thoughts?

jimh posted 05-28-2007 09:42 PM ET (US)     Profile for jimh  Send Email to jimh     
Perform the following test:

--turn on all the electronic devices on your boat

--turn your battery switch to OFF. If you have more than one battery switch, turn them all to OFF

--make a note of any electronic devices which are still operating

The electronic devices that continue to operate when the battery switch is in the OFF position will have to be manually turned off when you leave the boat

It is hard to say precisely how your boat is wired, as there is really no standard arrangement, and boats are always subject to modification by owners. Electrical haywire is quite common.

I would recommend you configure the electrical system on your boat so that all electrical loads are OFF when the battery switch is in the OFF position with the exception of a sump pump which operates by a float switch in conjunction with a control switch. You can leave the pump in the automatic position to help clear rain water that accumulates in your boat and drains to the sump.

When I leave my boat unattended, I always turn the main battery switch to OFF. This insures that there is no load from some electronic device or a cabin light that was left on. Even a small load can drain a battery over a week's time.

Chuck Tribolet posted 05-28-2007 10:17 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
And I'd get things rewired so all the accessories are wired
through the accessory switch. That's what it's there for.


mccomas posted 05-28-2007 11:45 PM ET (US)     Profile for mccomas  Send Email to mccomas     
If shore power is available or if you park your boat in a garage, a low cost trickle charger would keep your battery fully charged. I wired mine to connect through the 12VDC receptacle. The battery stays fully charged even with the electronics energized.
BarryGreen posted 05-29-2007 08:38 AM ET (US)     Profile for BarryGreen  Send Email to BarryGreen     
As Jim correctly notes, ordinarily the only piece of equipment that should bypass your battery switch and be "available" all the time is your bilge pump. The only exception I've found is that some AM/FM/CD radios have a "keep alive" wire that also bypasses the battery switch. This keeps the AM/FM pushbutton station settings in memory, and the drain it puts on your battery is miniscule. Most modern marine electronics (GPS, etc) keep their settings in non-volatile memory, and don't require a "keep alive" connection.


bkloss posted 06-01-2007 09:28 AM ET (US)     Profile for bkloss  Send Email to bkloss     
I have a brand new outrage 210 with a Verado that should be wired the same. If the electronics were installed at the factory, they would be using the accc. buss box with no switch. They should be drawing little or no power but I am puzzled why the dealer told you to to leave the switch in the "all" position with the expected result of draining down both batteries. The new Whaler 210 series uses a switch that if the engine is not running and the switch is left at either #1 or #2, the electronics will only draw from the house battery (Port battery). This is designed this way so in case you draw down one battery, you can switch to the other, starboard, to start your motor.

If you were leaving your boat, I would turn the battery switch to off which only allows your bilge pump to work as it bypasses the battery switch.


jimh posted 06-01-2007 09:49 AM ET (US)     Profile for jimh  Send Email to jimh     
"...I left the boat with the battery switch in the 'all' position as advised by the dealer...

I do not think the dealer gave you good advice on this. I would not operate or store the boat on a routine basis with the battery switch in the ALL or BOTH position. This simply invites the exact situation you have encountered: two dead batteries.

bkloss posted 06-01-2007 03:33 PM ET (US)     Profile for bkloss  Send Email to bkloss     
I need to make a correction to my previous post - The house battery is the starboard battery (#2) not the port battery (#1) as previously indicated.


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.