One Perko 8501 Battery Switch with Two 12v batteries and a 100hp Yamaha and t9.9 kicker Sharing the battery bank.

[Zedde]

Hi,

I have One Perko 8501 Battery Switch switch position 1...All..2 with Two 12v batteries a 2000 100hp Yamaha and 2016 Yamaha t9.9 kicker with electric start and tilt/ trim with charging capability. Both engines are commected/charging the one battery bank. I just bought the 2000 boat and engines as a package I am 4th owner but it appears the first owner bought both engines the one Perko switch seems to be there since the beginning. The last owner (had it 1 yr used 3 times) said he bought it the same as I have indicated.

I have been told even by a reputable boat sales and engine parts and repair...they say there is no concerns with one Perko switch, two batteries and two engines running at the same time under "All" to location..then shut down engine and switch to 1..cannot switch while the engines are running but can use switch position one as well.

I also have heard from others that its not recommended to run the two engines at the samw time on two batteries and one Perko switch or even having one off...the concern is the engine charging is different and one could burn out the diodes or charging alternator etc on the other...they say I need two Perko switches and to separate the engines..

I alos heard two Perko switches are not rwcommended either..

Not sure what to think or do..

I would like to know if there has been engine failures with this scenario or is it just theoretical? Or is there no concerns..

Thank you in advance...

Zeddy

 

[AllDodge]

I don't see a issue using it this way unless one of the Bats or motors develop a problem. If a Bat starts shorting out it will take both Bats down. If a motor develops a power drain it will drain both.

As a minimum setup I would have each motor connected directly to each Bat and use the switch to connect to the other Bat only if needed. The best would be use 2 switches

Now if you use 1 Bat for house loads and the other for starting both motors could do something like this

 

[Zedde]

I don't see a issue using it this way unless one of the Bats or motors develop a problem. If a Bat starts shorting out it will take both Bats down. If a motor develops a power drain it will drain both.

As a minimum setup I would have each motor connected directly to each Bat and use the switch to connect to the other Bat only if needed. The best would be use 2 switches

Now if you use 1 Bat for house loads and the other for starting both motors could do something like this
View attachment 37106

 

[Zedde]

Thank you for all your feedback its greatly appreciated.



The majority of the responses indicate that using one Perko 8501 Battery disconnect switch with two engines and two batteries is a typical and proven installation with some failures found on older engines over 250HP . I have been advised that it is possible to run both the 100HP and 9.9HP kicker at the same time at idle speed and only short durations only.


I have received two wiring diagrams and they both appear to be valid just wondering what the best installation is for this Perko switch with positions Off/1/All/2


Would like to run both engines at the same time just for a short period at idle. Planning to run out to site with the 100HP engine and then place in neutral and lower and fire up the electric start kicker until it warms up and then shut off the main. Would do the same going back home the kicker would be running at low speed trolling then fire up the main engine in neutral at idle speed once the main warms up then shut the kicker off use the licker trim and raise the kicker out of the water.


Both batteries are identical group 27 Gell cell batteries. Everything except the downriggers are connected to the 2 battery, battery bank


Both electric downriggers are wired to battery 2 so when the kicker is running it charges battery 2 to keep the downriggers powered.


I would like to primarily to stay in the "all" position all the time but maybe its best to run to site in "all" then shut down all engines then switch to 2 and have the kicker charge both batteries then do the reverse when leaving this is not preferred method.


It would be great if you could provide your feedback on using either diagram #1 or diagram #2. It appears diagram #1 maybe better since it provides more isolation of the two engines since they both are wired to their respective battery first.


Thank you so much for your time



Diagram # 1:

Diagram # 2:

 

[AllDodge]

Diagram #1 will work but;
The kicker most likely doesn't have enough of an Alternator to be able to charge both Bats if that is needed. The down riggers shouldn't draw a Bat down enough to worry about. Keep down riggers on Bat 2 and not connected to the switch

With Diagram #1 just leave switch in position 2, don't even bother with moving it unless your unable to start main motor sometime. The kicker will produce enough to keeps Bat 2 charged.

Assumptions I'm making
Bat 1 and Main motor also run gauges, motor, blower and other things. Bat 2 only runs Kicker and Dist panel for down riggers

If it was me, I would connect Main motor to Bat 1, Kicker to Bat 2 and also Distribution panel
Connect Bat switch Common to Main motor Starter
Connect Bat switch position 1 to Bat 1
Connect Bat switch position 2 to Bat 2

Bat 2 connect Kicker and Dist panel direct off Bat 2 positive
Bat switch stays in position 1 unless placed in OFF or ALL

This way if you need to combine Bat 1 and 2 to get Main to start you can, otherwise each motor will keep each Bat charged

The down side is no way to disconnect Kicker and Dist panel from Bat 2