Prepare Me For Battle--HAVE to 2nd Battery

[Jeff T]

Here is the short of my situation. I decided to invest in stereo equipment. I did so knowing I would need to add a 2nd battery to run the stereo equipment. However, regretfully, I did not adequately research the process of adding a second battery before hand. Because of labor cost, I need to try to do this myself. I'm not scared to tackle it if properly prepared.

I have done research. I have read and read. I did a search for battery (pretty broad search) and read nearly every post that was relevant. I've read about battery isolators, Perko switches (not sure I fully understand the difference between the two), batteries wired in parallel, batteries in the 1 & 2 positions, and wiring diagrams. There are hundreds of pages and yet I still feel like my head is getting ready to explode.

Here is what it boils down to. I need to know what is considered the most SAFE, power efficient, and cost effective way to go about this (if there is a way to have all three)? I would love the setup to be hands off, meaning...I can switch the ignition to ACC (I believe that is the right term) to listen to the stereo w/o draining the starting battery. I would also love to be able to charge both batteries via the alternator when running the boat. I would prefer to not have to open compartments and switch batteries from 1 (or both) to 2 and vice versa...although I will base this on the feedback.

Now for what I have: 05 22V with one battery. At this point, that is all I can tell you. I believe this single battery has an on/off switch, but I can't confirm. I plan on going out to the boat tomorrow to take pictures of the current setup and report back. Again, at this point, I don't know exactly what I will be looking for and it will be dark.

Long winded post I know. But any help IS GREATLY appreciated.

[lee]

You would need an isolator or solenoid to do the job you want. The components above act like a battery switch and do it electronically the way you described.

[Jeff T]

Are there any advantages to having an isolator to a Perko switch? What are the basic functional differences between the two?

[spharis]

Just get one of these
http://www.bluesea.com/product.asp?P...&d_Id=&l1=&l2=

or get a switch and a $15 stinger auto isolator from ebay....

All in all its an easy way to have auto charging, andf a manual switch for emergency.......I will be doing this over this winter.

[chpthril]

Here is a diagram of my third battery install. I think it might help you fi you just ignore the 1 deepcycle.

Like Lee said, the isolatores job is to allow the alternator to keep both battery banks, starting and accessory, charged without letting one pull the other down. Like a one way electrical valve.

My setup uses both the iso and a 1/2/both/off switch. This allows it to be a 'hands off' sys but the switch gives me some flexibility. If my starting battery fails, I can switch over (batt 1 to batt 2) and start the eng on the deepcycle. I can also turn the whole thing off.

My 06Ve came with 2 batts, 1 start and 1 deep, My head unit was wired to the starter batt, and the amps were wired to the deep. I rewired the power for the stereo to the deep. This will prevent the starting battery from running down while running the tunes @ anchor. this also means my stereo stays on after the key is shut off no more interruptions in the music while the key is turned from RUN to ACC.

[R&T Babich]

I added an AUX battery to our last boat and will be upgrading our 2000 21V soon. There are things to consider:

Battery types - your main should be a normal battery and the AUX a deep-cycle.

Charging - there are several devices on the market. I used the cheapo isolator method for 5 years with no problems. Get a good one, twice the alt amps. An isolator keeps one battery from draining the other, but allows the alt to charge both. An isolator is just a solid state Y-splitter with one-way valves (diodes). Current goes in the center post and out the sides.

Switching - use a MAIN-AUX-BOTH switch. Since you've got 2 batteries add flexibility. (You don't need this to run the stereo.) Normally run with MAIN for starting. If MAIN isn't enough, use BOTH. If MAIN is shorted, use AUX to get home.

For a high amp AUX circuit I would either trigger a relay with the ACCY position or run a seperate AUX switch. Make sure to add a high amp marine breaker in the AUX circuit. Email any questions.

[Jeff T]

chpthril,

if you can still power your stereo w/ the key shutoff, how do you make sure you don't draw power when the boat is stored? Do you manually turn off the batteries with your 1/2/both/off switch?

[Moki]

Chpthrl,
Where are you storing your 3 batteries? Do you have one where the TAPS pump is located (starboard) and 2 on the portside or is one of your batteries in the storage area? Nice setup, by the way

[chpthril]

Jeff T, Both my other boats I installed a 2nd batt and switch and had the stereo straight wired to the batt. It's like second nature to turn of the HU at the end of the day. The factory on/off switch does nothing more than interup the POS to the starter. It did not prevent anything else from being left on: light, bilge, blower, etc. If I leave an accessory on, the deepcycles will run down but the isolator will keep the starting batt from draining. As far as longterm storage, the HU memory probably draws about 25 milliamps. too deepcycles should handle this ok between charge-ups (I plan on plugging them up about every 4 weeks over the winter)

I HATED having to wait for the HU to power back up when u shut off the eng and go to ACC

Moki, Yes, over next to the TAPS. The factory set-up has the starter and deep on the port side. I got about 10 of marine cable and teminals and made a harness and ran it across the transom to the 1st DEEPCYCLE.

[talltigeguy]

I hate to add confusion, but I have a question: I understand that all the batteries should be the same or else you have different levels of resistance during charging and your alternator will preferentially charge one battery over another if they are different types and may affect performance. Isn't that true? I personally would avoid different types of batteries.

The big boys at Wakeworld who put 8+ batteries in the boat say this.

BTW, I have 3 batteries installed as well. I put the third just behind the rear port side speaker in the storage area. It doesn't seem to move. I currently have it hooked up to the other battery on that side. I only have a perko switch - when it is in the 2 position it is running on the 2 batteries and the 1 position is just one battery.

To add more confusion, I bought Optima batteries because I like the idea of not having to worry about adding water or spilling acid all over. I do not have them in the plastic boxes that the factory batteries came with. Optimas can better tolerate full draw downs as well.

I left the head unit connected to the accessory switch so I get that annoying pause when I turn the boat off, but I connected my amps directly to the batteries. Keep in mind that means that when I have the Perko switch in the 1 position, everything comes from the 1 battery except the amp will draw the other two batteries down. Most of the time I keep it in the 2 position and that isolates the 1 battery and saves it just in case I run things down. The amp turn on wire comes from the head unit so they turn off when the head unit is off. I don't trust myself enough to remember to shut off the HU every time out.

[dogbert]

Whatever option you choose, make absolutely sure that your head unit, amplifiers and any other electronic component that's attached to your stereo is grounded to the same circuit (battery bank) and, if you're using a battery isolator, make sure the power and ground are attached to the same circuit (battery bank). If you don't you'll get buzzing and popping.

[chpthril]

This is what is so cool about this forum, if you get enough heads together, you can cover all the bases.

Good point Tall, u don't want to mix wet cell (standered auto/marine acid and lead plates) and gel cell (optima). I don't know about putting 6v golfcart batts in with a 12 volt starting batt for that reason. If you added an alternator just for the 6v's you might be ok!

Dog, I didn't even think about swappin the grounds One more thing to add to the 'ta do' list

[dogbert]

Originally posted by chpthril
I don't know about putting 6v golfcart batts in with a 12 volt starting batt for that reason. If you added an alternator just for the 6v's you might be ok!

My golf cart has a 12v battery...of course it's gas and it's a Harley-Davidson ('57). Doesn't get used for golf anymore, but it comes in handy for running liquid refreshment down to my boat

[Jeff T]

Thanks Everyone for all the information. Keep it coming if you have more.

I have a question...and I'm going to expose my ignorance with this one: Can someone give me more specifics on the cables that I need to use? Where can I get it? Same size all around? Again, I would rather sound stupid here than to have to report that I fried something costly.

Thanks.

[dogbert]

Originally posted by Jeff T
Thanks Everyone for all the information. Keep it coming if you have more.

I have a question...and I'm going to expose my ignorance with this one: Can someone give me more specifics on the cables that I need to use? Where can I get it? Same size all around? Again, I would rather sound stupid here than to have to report that I fried something costly.

Thanks.

My Tige dealer made me the cables I needed. I didn't have the crimping tools needed to do it, so it was just cheaper that way. Just tell them you want some battery cables and approximately how long they need to be.

As for wiring the amps, you're going to want something substantial. I used battery cable for that as well. I know there's a formula for how thick your copper cable needs to be for the particular amperage you're pulling. You can get the number of amps from your amplifier specs.

Just remember, the thicker the wire, the cooler it will run your stuff. Obviously, there's a point of diminishing returns.