How should I hook my batteries up

"My boat currently has two bat

"My boat currently has two batteries attached to a perko switch with a 1, 2, or both option.

Since I bought my boat I have added an 800 watt amplifier for the sound system as well as added a DC to AC power converter. To accomodate for the added electrical load on the system I am planning on adding a third battery. My plan is to use two of the batteries for the sound system and power converter and the other battery used strickly start the engine. One of the batteries on the boat is bad anyway and need to be replaced so I figured I'd just get two identical batteries while I'm at it.

My question is how to hook the two battery bank together to keep it at 12 volts. Will it take one or two jumper wires? As in do I hook the (+) terminal of one to the (-) of the other battery. Or do I need two wires (+) to (+) and (-) to (-)?
Also, which of the batteries gets the (+) and which one gets the (-) lead coming from the alternator.

I have the amp and power converter connected through a distribution block with 2 gauge wire running from the battery to the distribution block and one 4 gauge wire running to the amp and one running to the power converter respectively. The power wire leading to the amp is wired directly to battery 1 without going through the perko switch. Should I wire the power leading to the amp to the perko switch allowing me to turn the flow of electricity off if need be?

Thanks for any advice you can provide."

positive to positive
negative

positive to positive
negative to negative

run in series

What I would do. Buy a second

What I would do. Buy a second switch. Connect all battery negatives together. Connect the two sound system batteries to the new switch and place on "both" when in use. This puts the two batteries in parallel doubling power capacity at 12 vdc. I'm assuming this sound system will be in use when the engine is not running thus really depleting the batteries. Having the switch allows you to charge the sound system batteries individually thus not straining the alternator and you have a backup pair of batteries for emergency starting.

"More info. Switch 1 has the

"More info. Switch 1 has the engine starting battery to terminal 1. Output of switch 1 to engine as already is. Connect the output of switch 2 to the sound system AND terminal 2 of switch 1. If you want to charge the sound system batteries turn switch 1 to terminal 2. Switch 2 can be on 1, 2 or both depending if you want to charge batteries independently or in parallel. If switch 1 is on both you can charge all three batteries simultaneously if the alternator can handle the load."

"Thanks for your ideas.

Jus

"Thanks for your ideas.

Just-in-Time, in your scenerio how do I hook up the power cables? Positive to battery 1 negative to battery two? or both positive and negative to the same battery?

Richard, you're right. the reason i want the two battery bank is for powering the sound system while the engine is off.

When you say hook all the negatives together, do you mean all three batteries or the two battery bank?

My boat's batteries are each on one side of the boat, about 8 feet apart. So adding a second switch and hooking up as you described might be too much. Nevertheless, if I do it like you described I want to fully understand what you mean.

Switch 1:
Leave terminal 1 as is. Output coming from terminal 2 of switch 2 connected to terminal 2 of switch 1.

Switch2:
Hook up each of the two battery bank to terminal 1 and 2 respectively. (running output of terminal 2 to termina 2 on switch 1)."

"Hook the negatives of all thr

"Hook the negatives of all three batteries together. I don't have a perko switch in front of me but I believe the terminal contacts (brass terminal studs) are marked with "Bat1", "Bat2" and "load" or something similiar.

Switch 1:
Leave terminal 1 (Bat1) as is (This is your connection to the engine starting battery positive terminal.) Output coming from "Load" terminal of switch 2 connected to terminal 2(Bat2) of switch 1 as well as the amplifier distribution block.

Switch2:
Hook up each of the two battery bank to terminal 1 (Bat1) and 2(Bat2) respectively. (running output("load" terminal) of switch 2 to termina 2 (Bat2) on switch 1 and the amplifier distribution block.

If you do it this way this is what you have:

Switch 1 on "1" Switch 2 on "both": Engine starting and running or anchored (engine off). Two amplifier batteries in parallel for the music playing. No charging on the amplifier batteries but No drain on your starting battery either.

Switch 1 on "both" and switch 2 on "both": All three batteries charge when engine is running. If you anchor don't leave the switches in this set up with the engine off cuz you will be draining all three batteries through the amplifier. At anchor put switch 1 back to "1".

Switch 1 on "2" Switch 2 on "1" or "2". Engine running you will be charging one of the two amplifier batteries depending on your switch 2 selection but not your starting battery.

Switch 1 on "both' and switch 2 on "1" or "2": With engine running the starting battery and one amplifier battery will be charging depending where you set switch 2.

So if your alternator can handle three batteries with two fully dead from the amplifier whith switch1 on "1" and switch 2 on "both". Then turn switch 1 on "both". Just remember if the enging is off put the switch 1 back to "1". We can get a little fancier by adding a marine contactor to automatically break the engine starting battery connection when you turn the key off so you don't have to set switch 1 back to "1" when off and a time delay relay to reconnect the two amplifier batteries back to switch 2 after the engine is running.

My alternator only puts out 63 amps and with my house load on it is barely charging at night. That's why you may need tha ability to charge 1,2or 3 batteries independently."

"Richard

The perko switch h

"Richard

The perko switch has three terminals. 1, 2, and common. It doesn't have a place to attach the negative terminals of the battery as you described. Currently the negative leads of both batteries are grounded to the engine block.

Your explanation is greatly appreciated and makes sense. I can choose any combination of batteries to charge or run the amplifier and stereo on. However, I'm afraid that after a few hours of drinking and hoopla I will forget what perko switch to set to what.

If I just keep the current one perko switch and connect the (+) lead of the two battery bank to terminal 2 and the battery for starting the boat to terminal 1, will it accomplish the same task? Except, being able to selectivey charge either battery in the battery bank, of course. I'm not concerned if the two battery bank gets run down. I'll be honest with you we hardly stay in one place long enough with the engine off to run the batteries down. The worst that can happen is we run out of music. If we do then put the switch to 1 start the boat move the switch back to 2 so the running engine can charge the two battery bank. What do you think about this scenerio?"

I didn't mean to indicate

I didn't mean to indicate connecting the three negatives at the perko switch. Just connect the three negatives at a common point such as your engine block is fine. Just don't anchor with the switch in "both" and you'll be fine. I haven't mastered walking on water yet (though I've tried unintentionally) so I take extra precautions for transportation back to port. What state is this party boat in?

My boat is in Florida.

My c

My boat is in Florida.

My current project is to re-upholster the interior of my boat. Once that's done I'm going to start on the battery bank.

Thanks for your ideas and explanations

"Wow. Year round boating. Ni

"Wow. Year round boating. Nice. One thing to keep in mind if two batteries are paralled + to + and - to -, if a cell in one battery goes bad you will be destroying the good battery. I had a marine diehard go bad in less than a year. Keep an eye on your ammeter. If it doesn't trickle down then more than likely you have a battery problem."

"Hey. I been thinking. (

"Hey. I been thinking. (My wife hates when I do that.) We could also put lights (LEDs)on your dashboard to show which battery or batteries are being charged or discharged as a reminder of how the switches are set. Three LEDs, one per battery. If the led is green then that battery or batteries is being charged. The same LED changes color to red if that battery or batteries is being discharged. If an LED is not illuminated at all the battery or batteries is just sitting there waiting for a load or the engine to start. (Okay I like power electronics.)"

"I'm planning on buying tw

"I'm planning on buying two new batteries come spring for my project. I'm also going to get as long a warranty as possible to protect against one or both going bad.

I probably should of mentioned it, we use my boat 100% of the time in fresh water florida lakes. We don't ever take it off-shore or far from where other boaters are. I am more concerned with making my proposed project as simple as possible. If I had a boat that spend most of its time in the water or was used to go miles off-shore I would be more apt to go your way with the two perko switches and LEDs.

For my project getting the two battery bank to act as one and isolating the sound system from the starting battery is plenty fine."

"You could make it easier and

"You could make it easier and less confusing and hook up a relay to connect both batteries when the key is on ( which will use both bat. to start the boat and the alternator will charge both) and when the key is off have the stereo run off of one battery only. So basicly, when your stereo runs too long and shuts off and all you have to do is simply turn the key to start the motor and the relay will close for the starting battery to join the system."

"1st boat, What Jeremy is refe

"1st boat, What Jeremy is referring to sounds one of the BlueSeas systems... all ready to install, and built to last.
This can be set up to give an entirely isolated "Reserve" cranking battery, run your house loads from a bank of Deep Cycle batteries, gives an auto-combine mode for cranking, yet gives you the ACR feature that would allow engine alternator charging of both banks.
http://bluesea.com/files/images/products/7650.jpg"
With this system, you would benefit from a dedicated cranking bank, and multiple Deep Cycles for your HB.


Now, if you want to keep this simple and inexpensive, just use a standard MBSS, like your Perko unit.
Switch to # 2 when on the hook or just hanging out using your stereo.
http://sports.webshots.com/photo/2474911180035924090ZWBVlR]


Look at schematic "G" on this page. [url=""]http://dolphinmarineservice.homestead.com/ele2.html[/url]
Forget the isolator (approx .7 voltage drop with an isolator) we don't use these much any more.
Note the connection of the O/B charger.
Note [b]NO[/b] leads going to the batteries other than battery cables.
The "Common" cable to the engine starter motor ultimately supplies your boat's hull harness, helm, instruments, etc.
[b]KIS[/b]... Keep It Simple!
You need only one MBSS.
Manage your banks manually keeping # 1 in reserve.
If concerned that this isn't doable...., see the BlueSeas system above.


FYI: I'd not jump battery banks and connect Negs together.... each bank Neg is best if it makes it's own engine connection.... it's called "redundancy"."

"1st boat, mate the last thing

"1st boat, mate the last thing i want to do is offend you but if you have no idea of what your doing at the begining of this post and now at the end you have some idea...you now know enough to be dangerous (only joking) if you stuff the installation up you risk blowing up a battery or two, getting covered in battery acid, boat catching on fire etc etc. Take it to a marine or auto sparky who can do it for you."