Perko switch proper operation

[Justcuz]

We’re new to cruising. Bought a beautiful Island Packet 29 and we’ve been spending a fair bit of time learning the ropes and getting to know her.

Tonight after we finished practicing reefing we had an engine restart issue (yanmar 2gm). Basically, when the key was turned on the buzzer would go, fan would turn on, but when the button was pushed the engine wouldn’t fire. Had our first tow!

Here’s my question; trying to determine if perhaps the issue is the way I’m treating the batteries (there are three on a perko switch). When we fire the engine, we turn the switch to 1 which is a dedicated engine battery. Immediately we turn the battery switch to 2 (house batts) after the engine fires. Is this normal operating process or should we let the alternator charge the engine batt for a while before flipping to house batts?

We do not use shore power due to the boats storage location. There is a solar panel that I believe only feeds the house batts. I do turn off the perko switch when the boat is not being used (bilge is direct wired).

Thought comments and criticism welcome.

[Frankly]

First thing is very typical to find modified electrical system after many years, so you are going to have to get familiar with your actual set up. Get a digital VOM, even cheap version will suffice for most trouble shooting.

Switching the battery switch while the engine is running is generally a bad idea (alternator diodes can be blown).

Checking battery voltage to determine state of charge would be first (full charge typical 12.7 volts).

On IPs the Yanmar panel is typically installed with a wiring harness extension. This extra wire requires that everything be up to snuff to prevent starting problems. Some have installed an extra strating relay to overcome this but i have not had problems when the electrical systemmis good.

Check the battery voltage (IP Panel ) under no load and again while starting. Report back.


IP Home Port is also a great source of help/ info.


Frankly

[smac999]

generally you'd start on 1, run the engine on all. to charge all batteries. then switch to 2 when you shut the engine off.

[HopCar]

Make it a point to not switch through the OFF position while the engine is running. If the switch isn’t wired with a field disconnect circuit you can damage the alternator by switching to OFF while the engine is running.

Did you try switching to the Both position when the engine wouldn’t turn over? It does sound like your start battery wasn’t getting charged. You should have been able to crank it with the help of the house batteries.

[Justcuz]

Thanks for the responses. I'll spend some time with a VOM meter, starting with batteries and working from there. Frankly I'll start with checking voltage under no load and again while starting.


I have read a lot about not switching while running but seems rather impossible if you're running for extended periods and need to use house batteries for things like nav, etc. Then IF you switch, there is some debate as to whether you should switch to "all" or just to "2" so as to never draw from the engine battery. Look where that got me .

Hopcar good point about switching to all to just get a start.

Sounds like a date with my mulit-meter tonight.

[Wotname]

Welcome aboard CF, Justcuz.

As well as getting to know your Perko switch operation, you should learn how to use the decompression levers on the 2GM engine to assist in starting when the batteries are low.

The 2GM will start with an almost completely discharged battery by this method.

Set the power lever (throttle) to about halfway.
Decompress both cylinders by raising the decompression levers.
Operate the start switch and the engine should turn over easily
Let it spin for a few seconds building up flywheel momentum.
Lower one of the levers and with some luck that cylinder will fire.
If/when it does, the lower the other lever and release the starter switch.

You may need two people or fit a second starter switch in the engine compartment.

[a64pilot]

Leave the switch to ALL, why would want it in any other position?
If your paranoid about killing the whole bank, use an ACR to keep the starter battery charged and leave the switch on the house bank. Then the house bank and only the house bank will be used whenever the bank is below charging voltage, but regardless of the charging source, or even which bank receives charging voltage whenever there is charging voltage, the ACR will connect the starting battery to charge it, and automatically disconnect it whenever voltage is below charging levels and not discharge the stater battery.

There are other ways but an ACR is among the simplest, cheapest and easiest to implement.

This article should help
https://marinehowto.com/automatic-charging-relays/

[Heck]

The concept of having a house bank and an starter bank just doesn't make a lot of sense, especially if they aren't isolated, because if one is bad the other one is likely to become discharged through the ALL switch position.

After doing some research what I have done is run everything off the main bank (the largest) and having the smaller bank as a backup just in case the main bank dies. All the charging sources go to the main bank and the backup bank is charged off the main using an ACR. The battery switch is always on the main bank unless you need to go to backup.

Here's some good info thanks to Stu Jackson https://c34.org/bbs/index.php?topic=5977.0

[Justcuz]

Thanks for the ACR suggestion. Stupid question---that, then, would replace the perko switch? Or is the ACR added to it and perko switch can just stay on "all", and I never have to be paranoid?

Sorry--training wheels are on.

[Heck]

The issue with how the Perko switch is typically wired is that it controls both usage and charging at the same time. The idea of adding an ACR is making the switch only about battery usage and having the charging always the same.

Once you remove charging from the Perko switch then you can select whatever battery you want, including ALL.

[Cheechako]

My guess is you have a bad ignition switch. It's quite common with the Yanmar switches actually.
-Do you know your battery was dead?
-It could be your starter solenoid also.
-You weren't in gear were you? Some have a lock out switch so they wont start in gear.

Get to know your battery switch and charging system.
-Does it charge both start battery and house battery automatically?

[GWilly]

I’d second what a64pilot said about an acr and leaving the switch in All position. It’s what I’ve done and never had an issue.

[svchinamoon]

Suggest you buy a copy of Nigel Calder’s “Boatowner’s Mechanical and Electrical Manual” which should serve as a handy reference as you get to know your vessel systems. Cheers.

[Squanderbucks]

There are a lot different setups put forward on this forum about battery and switch wiring.
I have two banks and two battery switches ( both 1-2-Both-Off).
Start Battery is on one switch and House batteries on the other. They are interconnected to allow Both settings to draw from all together if needed.
Generally the engines are set to Start with one switch set to 1. And House switch is set to 2. Never need to change any switches in normal operation.
If for some reason either set of batteries had a problem the switches would just be set to the “good” bank.

Nothing except the engines run off the Start battery when its switch is set to 1. Everything else on the boat runs off the House batteries.

Battery charger goes to each bank and charges as needed when on 120v power is available.

Twin engine boat and one self regulating alternator goes directly to each bank. They would only charge the opposite batteries if the Switches were changed from their original “Normal” settings.
Has worked for me for 30 years in this boat.

Even with a single engine the setup could be the same with the addition some type of dual charger - which will start another thread.

[a64pilot]

Originally Posted by Justcuz

Thanks for the ACR suggestion. Stupid question---that, then, would replace the perko switch? Or is the ACR added to it and perko switch can just stay on "all", and I never have to be paranoid?

Sorry--training wheels are on.

Actually from a worried about dead batteries point of view, you would want to leave the switch to whatever bank the house bank is on, that way whenever anything is being charge, the ACR will close and charge both, but when the engine is off and it’s nighttime, you will only draw from the house bank, you can kill it stone dead and the start battery will remain untouched.

However if your IP is like mine, there is only so much battery compartment and I need / want as big a house bank as is possible, largely because the less you discharge it every night as a percentage of total charge, greatly influences its lifespan, and also I “need” a bigger bank, so I gang all batteries together with the ALL switch. I have a 440AH bank, and a 220 AH bank, together of course is 660AH.
I personally don’t see it as a problem, I see managing my banks SOC as being the same as managing my fuel tank, even if one battery is shorted and tries to kill the whole bank, isolate the dead bank and the other will recover enough to start the engine, or if for whatever reason it won’t, turn everything off and the Solar will bring it back up enough so that it will.