Perko Switch - Explanation needed?

[Zebco33]

I have (2) bats, with a perko selector switch that has positions:1, 2, Both or Off. I was told by SEATOW that I should either select the 1 or 2 when running and cannot switch to another postion when the engine is started and that I should only use the both postion when both bats are too week to start.

The explanation they gave me was that if I stay in the both postion, that I could decharge the bats if running at idle for long periods of time. I was told that my engine (200hp Johnson 2000) doesn't have the capabilities to charge both bats at the same time? I was skeptical and confused : :? that I drained my batteries cruising at slow speeds for 4+ hours.

any similar experiences, explanations or lessons learned on the matter would be much appreciated

 

[gradyfish22]

I ran my boat on both the first trip and killed my batteries, the seller never explained the proper way to use it, SHE said she always ran it on both, but she never really went far or for long. I did some research and found that the switched should NOT be on both, one should be on 1 and the other on 2...on my boat they point outboard to be in the correct position. I have twin engines so each engine charges each bank of batteries, but not one another. If you only have a single engine, I'd run your batteries on both when making long runs to charge both, but if it is a short run or you are idling a lot, switch to one or the other, if you kill that one you have one in reserve to get you going. I ran my single engine Grady this way and never had an issue ever.

 

[BobP]

You need to consider adding a daul battery charger.

 

[Curmudgeon]

Seatow gave you pretty good rational, except maybe for the switching part. Modern switches are "make before break" design, which means the new connection is made before the old one is broken (batts are momentarily paralled during the switch over). That being the case, you "should" be able to switch without damage EXCEPT TO OR THROUGH THE OFF POSITION! Having said that, I know from experience that Perko switches can be distorted by over-torgueing the mounting screws. Each position still connects what it's supposed to, but the "make before break" can be lost ... :cry:

 

[capt chris]

On a single engine dual battery application my experience has always been to use 1 or 2 to start and run the motor. Only use both if either 1 or 2 does not have enough reserve to start the motor by itself, then switch back to 1 or 2 after starting. The problem with running in BOTH is if one battery has a bad cell it will drain the other good battery and ruin it. Obviously if it took BOTH batteries to start the motor one of them is on its way out. If both batteries are relatively new then you can use the other battery as a "house battery" to run stereos and electronics when the engine is off and still have one battery ready to start the motor when you're ready to leave. It has always worked for me over the last 21 years.

 

[uncljohn]

There is some validity to that. I know w/ Yamahas, anything older than approx 2001(I think) did not put out enough amps to properly charge 2 batteries at the same time. Newer Yams put out higher amps and SHOULD be able to handle 2 batteries. But no sense chancing it when you don't need to.

 

[Greg B]

There is some validity to that. I know w/ Yamahas, anything older than approx 2001(I think) did not put out enough amps to properly charge 2 batteries at the same time. Newer Yams put out higher amps and SHOULD be able to handle 2 batteries. But no sense chancing it when you don't need to.

2000 Yamaha 250s have the capability to charge two batteries.

 

[capt chris]

I checked the Yamaha website and the F250TXR puts out 46 Amps @ WOT. I don't know if that's enough to charge two batteries simultaneously or not, but how often are you running at WOT? The output surely is less @ 4000 RPM cruising and even less when trolling. I would still only use BOTH only when you can't start the engine on either of the batteries alone. Just my opinion, I'm certainly no electrical engineer. Maybe the best thing to do is call GW customer service or Yamaha CS and ask them.

 

[Zebco33]

thanks all on the input. my lesson was learned - after receivin an $800 bill for being towed back to the docks. selector switch either in 1 or 2 and only both when in an emergency.

 

[Curmudgeon]

Yamaha has wiring that can deliver whatever amps are available to two batteries. Might charge both if run WOT for several hours.

$800 is 5 years worth of SeaTow ...

 

[plymouthgrady]

batts.

The simple explanation is that your batteries will only charge as strong as your weakest battery. What that means is that a strong battery won't charge a weaker one up but rather a weak one will draw a strong one down so they are equal. (What happens in the 'both' pos.)
On Day one run on "1" and charge it up. On day 2 on "2". You can put it on both for start up if you choose but you really don't need to.
Do not get into the habit (or at all) of switching the batt. switch while engine is running.

 

[Grog]

Outboards are really bad as far as charging. Newer ones put out more amps but they also use a lot of that power to run. If you can, make a dedicated house and a dedicated start battery, an automatic charging relay to switch the charging, and a combine switch.

 

[capt chris]

Re: batts.

The simple explanation is that your batteries will only charge as strong as your weakest battery. What that means is that a strong battery won't charge a weaker one up but rather a weak one will draw a strong one down so they are equal. (What happens in the 'both' pos.)
On Day one run on "1" and charge it up. On day 2 on "2". You can put it on both for start up if you choose but you really don't need to.
Do not get into the habit (or at all) of switching the batt. switch while engine is running.

Plymouthgrady is right about switching the battery switch while the engine is running unless you have a "make before break" selector switch. With one of these contact is made with both batteries briefly before being switched completely over to the other battery. That way the current from the alternator always has a place to go and will not blow the diodes on the alternator. What you should NEVER, NEVER, NEVER, EVER do is turn the battery selector to OFF with the motor running.

 

[JUST-IN-TIME]

yes most switches are make before break

you want a starting battery on 1
deep cycle on 2

you start on 1, switch it over to 2


deep cycle are for long low amp draw drains
stat is for fast high amp drains

 

[GT]

At the dock I start the motor with the switch in position #1 and leave it there for that half of the trip. Going home I switch to position #2. This way I start the motor using both batteries (at separate times) which might help me detect one being weak; AND they both get their own dedicated charging time while underway.
If I find myself using one battery more than the other (longer trips fishing, trolling,etc), I'll swap my routine the next day - start the day on batt #2, swap to #1 going home.
Seems to work for me.