Battery drain

[pxk3]

With the Perko Switch (1, 2, All, Off) in the Off position, is there any battery drain occuring with the wires connected to the batteries? I have been disconnecting the wires from boat batteries when the boat is not in use, even just for overnight. Am I being too cautious? Thanks.

[dlandersson]

Yes.

With the Perko Switch (1, 2, All, Off) in the Off position, is there any battery drain occuring with the wires connected to the batteries? I have been disconnecting the wires from boat batteries when the boat is not in use, even just for overnight. Am I being too cautious? Thanks.

[Tomfoolery]

I have been disconnecting the wires from boat batteries when the boat is not in use, even just for overnight.

That's what you're doing when you set the battery switch to off. The wires don't use, consume, or transfer any battery energy on their own, especially with direct current. The batteries are another story, as they discharge themselves over time no matter what you do, and the warmer the weather, the faster they self-discharge. A good charger with float capability is a good thing to have.

[u12fly]

Wait... There just is not enough info here to give you the correct answer

There are many ways to wire the boat, and I've seen many things by-pass the perko switch and hook straight to the batteries. Take a look at you batteries and trace the positive leads, if the ONLY thing on the battery positive leads is the large wires(one from each battery) going to the 1-2 switch then that is a pretty good indication that there is no direct feed off the battery

[dlandersson]

Your battery problem is not the Perko switch - it's that homeless person that sneaks in each night and sleeps there.

With the Perko Switch (1, 2, All, Off) in the Off position, is there any battery drain occuring with the wires connected to the batteries? I have been disconnecting the wires from boat batteries when the boat is not in use, even just for overnight. Am I being too cautious? Thanks.

[kmclemore]

Wait... There just is not enough info here to give you the correct answer

There are many ways to wire the boat, and I've seen many things by-pass the perko switch and hook straight to the batteries.

Indeed. My Xantrex Link 20 bypasses the switch, for example, and it uses a surprising amount of energy.

[mastreb]

Yep, your boat >should< be wired so that "off" means off, but some various dealers, POs, and installers seem to believe that some certain piece of equipment is so important that it should be directly wired to the battery. In my experience, that's always a mistake because it makes it impossible to leave the boat unused for any period of time without killing the battery.

Correctly wiring your boat with an "all off" Perko switch can save you needing a separate house battery. I run a single deep-cycle group 24 for both house and start and have for three years. We've never run the battery dead even when camping on the boat for a week.

What makes this possible:

-- I have an ETEC-60, which makes 27 amps of charging power so even small marina in-out maneuvering keeps the battery topped off. We don't charge the battery in port and we don't have any solar. Nothing but ETEC charging has worked a charm for three years thus far.
-- If everything is dead, I can pull start the ETEC. I've done this once because I'd accidentally left the boat on for two months. While it's a bit of a hassle, it works and means I never have to worry.
-- Cabin lights replaced with plug-in LEDs (Nav lights not yet upgraded)
-- Separate circuits for "In port" vs. "underway" (work in progress--it currently only shuts off NMEA 2000 network). In-port will power only house circuits (cabin lights, water system, and anchor lights, whereas "underway" activates the NMEA 2000 network (chart-plotter, instruments), VHF, nav lights) etc. This way when we're in port we can cutoff almost all parasitic instruments. This switch is actually just a single SPST switch that activates the underway circuit, with the house circuit being always on.

We use our boat a lot, and while we don't live aboard or cruise, we do camp on it for extended periods while we do day trips, and we do it year-round as there's no season for us. Setup correctly, a single battery works just fine and has never been a problem.

[Catigale]

DIsconnecting the cables is overkill. If you look at battery self-discharge rates, it is typically 1% per month, although Ive seen claims of "1-60% per month (pretty useless info, IMHO)

Make a wiring diagram of all things connected to your battery - take a pic and label what is what and put in your logbook - good info to have at your fingertips, btw,

[Tomfoolery]

I've never had any loads on a boat, any boat, that wasn't after the battery switch (other than a bilge pump), but if in doubt about parasitic loads, the OP could always stick his DMM in series with one of the battery terminals and measure current. Just use a high range first, as pulling a lot of current through the low range portion will blow a fuse (or the meter). But if it were me, I wouldn't have anything before the switch other than a bilge pump, if required, but Mac powersailers don't really even have a bilge.

[Russ]

I agree that totally disconnecting is overkill on our boats. Well on any boat. Doing so is creating more complexity and fatigue on terminals. Don't do it. As long as you turn everything off, everything should be, well, off.

Having a bilge pump hardwired isn't necessarily a bad thing. I don't see a need for a bilge pump on a boat without through hull fittings, but others seem to get a lot of rain water in and that might help.

I don't have a battery switch. I have a starter battery hardwired to the motor and a house battery hardwired to the panel. I do have one direct (fused at the terminal) hot lead to the stereo that keeps the presets and clock going. The drain on this is probably not even measurable. When we leave, we turn all loads off at the panel. The only drain possible is from the radio memory circuit to the house battery. The motor is turned off and should have zero drain on the starting battery.

We should be aware of how our boats are wired, especially if a previous owner has done some creative wiring. As mentioned, trace everything down to be sure nothing is actually ON.


--Russ

[mastreb]

Of course after posting that off means off, I'm now considering direct connecting the motor to the battery (not through the perko switch)

Reasons are:

1) I think there's no parasitic load when off ( anyone actually know?)
2) will be able to raise and lower without going aboard
3) will be able to start and leave the marina without opening up the cabin
4) will always charge correctly even if the perko is accidentally off.

This came up because while towing through Wyoming I had to lower the motor at the border so they could verify no mollusks, and that was major PITA to open up a boat that had been secured for cross country travel just to lower the outboard.