Perko switch with 3 batteries!

[MistahBiz]

Hi all,

I"m wanting to make my boat self-sufficient regarding my batteries. I have a 90 merc 4-stroke (carb) i have one dedicated battery to the motor, also I have two 12 volts in parallel to run my 67lb thrust motorguide trolling motor. I want to be able to charge my trolling motor batteries with my main engine (rather than plugging in at home) What kind of perko switch do I need for this? I'm also going to add some lights (led) since they have a low draw, for crabbin and night (catfish) fishing. I plan on using the two front batteries to run those.

Thanks in advance,

Mistahbiz

 

[Don S]

Re: Perko switch with 3 batteries!

I wouldn't use any "Perko switch" I would use the Bluesea add-a-battery to keep both engine and house/trolling motors separate, and charged automatically.

Have a read about them here. Add-A-Battery - 120A - Blue Sea Systems

Buy them here Blue Sea Systems Add A Battery - iboats


Here are some lesser options without the ACR. http://forums.iboats.com/electrical...ors/wiring-up-dual-battery-switch-597964.html

 

[NYBo]

Re: Perko switch with 3 batteries!

also I have two 12 volts in parallel to run my 67lb thrust motorguide trolling motor.

Are you sure of that? I would think that motor would be 24V, not 12V.

 

[MistahBiz]

Re: Perko switch with 3 batteries!

Thanks Don I'll read up on that. Bob, yes its 24 volt trolling motor..it has a 12 and 24 switch. Mine only works when its on 24...isn't that what two 12 volts in parallel is? or is it in series?

Thanks

 

[Don S]

Re: Perko switch with 3 batteries!

isn't that what two 12 volts in parallel is? or is it in series?

Parallel = 12 volts
Series = 24 volts.

Battery switches and acr's are not going to work with 12 and 24 at the same time. You need and on off switch for the 12 volt battery, and an on off switch for the 24. Two complete separate systems. and you can't charge 24v with a 12 volt charging system.

 

[glenn property of pam]

Re: Perko switch with 3 batteries!

there are ways to make the boat self-sufficient regarding the battery set up you have but there not cheap especially as you will need to transfer alot of power from the motor to the trolling batteries in a very short time. most people end up buying a whisper quiet generator and charger.

 

[ondarvr]

Re: Perko switch with 3 batteries!

Minn Kota has a charger that will connect everything correctly and keep all three batteries charged.

 

[glenn property of pam]

Re: Perko switch with 3 batteries!

Minn Kota has a charger that will connect everything correctly and keep all three batteries charged.

10 amp limit per bank isnt it.

 

[fishrdan]

Re: Perko switch with 3 batteries!

I have a 90 merc 4-stroke

Doubt that's going to be able to keep up with 3 batteries, or it would take a looooong time to charge depleted trolling motor batteries.

you can't charge 24v with a 12 volt charging system.

Yes and no. You can't charge the 24V bank directly, but you can break the 24V series connection and parallel the batteries for charging. It can be done with a Marinco 12/24 receptacle and plugs, though it's kind of a hassle swapping plugs... (moot point seeing the OP's OB probably doesn't have sufficient charging capacity)

10 amp limit per bank isnt it.

Yup, That's why I didn't go with MK's DC Alternator Charger. My take on that product, it's to add some charge back to the trolling batteries and extend runtime a bit, it's not to completely recharge the batteries (would take forever....)

 

[Todd4]

Re: Perko switch with 3 batteries!

Yup MK is 10 amp per battery. It'll fully charge your start battery first and then charge the other batteries. It works well, depending on your alternator output - but will take a long time to recharge your trolling motor batteries, just as any alternator would take forever to charge a car's starting battery if you left your lights on for a long time. Alternators are not intended to re-charge batteries - only keep them topped off after starting and using lights, etc.

Each MK charging circuit is isolated so you CAN charge 2 batteries in series (24V) without splitting them up into 2, 12V parallel circuits. If not, that would be a real pain to use. I have one, simply because they're relatively inexpensive and I might as well use my alternator's output to good use while underway, normally - even if it will rarely fully charge my TM batteries (every little bit helps).

 

[glenn property of pam]

Re: Perko switch with 3 batteries!

additional 24v alternator is the fastest way to recharge but even then its proberly 1 hour running the motor for every 1-2 hours of trolling and its not cheap especially as a marine alternator and all the additional parts required to install it.

 

[Don S]

Re: Perko switch with 3 batteries!

additional 24v alternator is the fastest way to ....................

Where are you going to put a 24V alternator on a 90hp Merc outboard?

Yes and no. You can't charge the 24V bank directly, but you can break the 24V series connection and parallel the batteries for charging. It can be done with a Marinco 12/24 receptacle and plugs, though it's kind of a hassle swapping plugs... (moot point seeing the OP's OB probably doesn't have sufficient charging capacity)

Please explain how you do that with a "Perko Switch" that the OP asked about originally.

 

[ondarvr]

Re: Perko switch with 3 batteries!

Yup MK is 10 amp per battery. It'll fully charge your start battery first and then charge the other batteries. It works well, depending on your alternator output - but will take a long time to recharge your trolling motor batteries, just as any alternator would take forever to charge a car's starting battery if you left your lights on for a long time. Alternators are not intended to re-charge batteries - only keep them topped off after starting and using lights, etc.

Each MK charging circuit is isolated so you CAN charge 2 batteries in series (24V) without splitting them up into 2, 12V parallel circuits. If not, that would be a real pain to use. I have one, simply because they're relatively inexpensive and I might as well use my alternator's output to good use while underway, normally - even if it will rarely fully charge my TM batteries (every little bit helps).

This is exactly why I mentioned it, it's the best option for the least amount of money and hassle. No system will keep his trolling motors fully charged if he uses them much.

 

[Todd4]

Re: Perko switch with 3 batteries!

This is exactly why I mentioned it, it's the best option for the least amount of money and hassle. No system will keep his trolling motors fully charged if he uses them much.

Unless you have a really really loooog ride back to the marina. :joyous: I still think it's worth it to install it and forget it (it works automatically) to at least use my excess alternator output to partially charge my TM batteries between use. JMHO

 

[ondarvr]

Re: Perko switch with 3 batteries!

You could connect this system to the tow vehicle and it would charge on the drive each way too, but again, the lake needs to be a good distance away for it to be relied on for a full charge. I would install one but the run on the water to and from the launch isn't long enough to do anything.

 

[fishrdan]

Re: Perko switch with 3 batteries!

Please explain how you do that with a "Perko Switch" that the OP asked about originally.

Wiring
- Perko lug #1 to start battery, Perko lug #2 to first TM battery. (bottom battery, 0V-12V of the 24V bank)
- Marinco receptacle wired independently (4 wires) to the 2 trolling motor batteries.

Use
- Insert a parallel jumpered "12V charging plug" into the Marinco 12/24 socket, then flip the Perko switch to charge the batteries.
- Turn Marinco switch to 1, then insert the series jumperes "24V trolling motor plug" into the Marinco socket to use the trolling motor.
(Doesn't have to be that exact sequence, as long as it's wired correctly, 24V won't get to the engine/electronics.)


Perko switch is needed to keep TM batteries off the start battery when using the TM, then allow the TM batteries to be charged when the engine is running.

(I didn't say it was easy... )

 

[Silvertip]

Re: Perko switch with 3 batteries!

Wiring
- Perko lug #1 to start battery, Perko lug #2 to first TM battery. (bottom battery, 0V-12V of the 24V bank)
- Marinco receptacle wired independently (4 wires) to the 2 trolling motor batteries.

Use
- Insert a parallel jumpered "12V charging plug" into the Marinco 12/24 socket, then flip the Perko switch to charge the batteries.
- Turn Marinco switch to 1, then insert the series jumperes "24V trolling motor plug" into the Marinco socket to use the trolling motor.
(Doesn't have to be that exact sequence, as long as it's wired correctly, 24V won't get to the engine/electronics.)


Perko switch is needed to keep TM batteries off the start battery when using the TM, then allow the TM batteries to be charged when the engine is running.

(I didn't say it was easy... )

There are two, three and four wire 24 volt systems. Let's get back to reality. A 90 HP Merc has (as I remember) a 16 amp alternator. That's barely enough to keep one battery topped off in short to medium distance runs much less two or three of them. You will never make that system self-sufficient from the engine. It simply is not worth spending the money to try. Most cars and trucks today have nearly 100 amp or more alternators. Use it, use a Honda 1000 watt generator that you could put in the truck and not hear it run, or install a solar panel the size of a 24 foot travel trailer and pray for 24 hours of sunshine. Sometimes ones recreational choices require a compromise. Fishing in an area with no shore power requires more judicious use of a troller or not using it all and relying on a kicker or drift sock if the big engine can't troll slow enough.

 

[fishrdan]

Re: Perko switch with 3 batteries!

There are two, three and four wire 24 volt systems. Let's get back to reality.

Correct, the one I was talking about was a 4 wire system (per DonS's request) and it really works. I didn't say it would work for the OP, I said just the opposite, that the 90HP OB wouldn't be able to keep up with 3 batteries.

 

[MistahBiz]

Re: Perko switch with 3 batteries!

Thanks everyone.. sorry I was out on the water!! Crabbing.. catching king salmon ..this summer has been awesome with the boat. I decided to not to mess with the charging system and just stick to charging at home..although I did pick up a Yamaha 1000 generator as a backup! Thanks again everyone....