Dual Battery System
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=17460
Printed Date: November-18-2024 at 12:32pm
Topic: Dual Battery System
Posted By: Hawktique
Subject: Dual Battery System
Date Posted: May-09-2010 at 9:03pm
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I have decided to install a second battery under the bow. My plan is to install a battery isolator above the engine breaker to charge the start and accessory batteries. Run a new 6 ga wire from the alt to the isolator (disconnecting the original alternator wire) , 4 ga from the iso to the accessory battery, the other isolator terminal to the engine breaker. both battery negatives hooked together (4ga) to keep a common ground. The accessory battery ground will now serve as the dash ground, fixing the common dash grounding problems.
I have also decided to re-wire some of the factory wiring. I would like to be able to turn the key off, shutting down the engine and hour meter, while keeping certain functions available. I plan to switch the bilge pump, lights, blower, and accessory breakers to run off the new battery: auto bilge in the event of taking on water while beached or tied up, stereo for obvious reasons, lights so I don't drain the start battery if the engine is off, and blower so I can just hit the breaker to turn it on while at the ramp. All this came about when I decided to add subs/amp and run them off their own battery, and then "while I'm at it, I may as well..." I'm looking for any input to make my upgrade better. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Replies:
Posted By: SN206
Date Posted: May-09-2010 at 10:27pm
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I thought about doing the same however, I heeded the advice of others from this site and bought a real good dual purpose battery. I use the piss out of the battery and never have I had a problem. As much as I payed for the battery it was still cheaper in the long run with less stuff to install. Does your 196 not come with accessory, bilge, blower switches on the dash that function while the motor is off? ------------- ...those who have fallen and those who will. |
Posted By: Hawktique
Date Posted: May-10-2010 at 1:48am
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I have a tendency to over think/do things from time to time. They will function with the ignition breaker on, but that also energizes the hour meter. I just thought about ending the "interlock" requiring the ignition breaker to be on for accessories to function. A lot of this wiring project also came after careful inspections of previous owners' botched wiring jobs. I have been doing aircraft electronics for the last 10 years, so that sort of thing really gets under my skin. The only cost to me was the isolator ($40). The rest of the materials I have around the shop and need a home for anyway.
I totally understand a good dual purpose battery is a simple and functional way out, but sometimes I like a little challenge of reinventing the wheel to my liking. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: 79nautique
Date Posted: May-10-2010 at 1:20pm
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No since in run 4 gauge wire if your only feed it with 6 gauge wire? seems a little odd to do it that way, if any thing feed with the 4 and then step down to 6. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Hawktique
Date Posted: May-10-2010 at 2:23pm
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The calculation there is the Amperage vs length of wire. 65-85 amp service for under 5 ft requires 10 ga, 5-13 ft requires 6 ga. The longer the power wire, the greater diameter needed.
The factory wiring goes from a 10 ga from the alternator, to 2 ga to the battery. I could get by with 8 to 4, but still may bump to 6 and 2 in case I put on a high output alternator. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: 8122pbrainard
Date Posted: May-10-2010 at 2:41pm
Josh, At what voltage drop? Since you're wiring, you might as well do it correctly and go with a 3% rather than the 10% your figures show. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Hawktique wrote:Posted By: Hawktique
Date Posted: May-10-2010 at 2:49pm
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My reasoning for this post. I've just been going off a couple charts from different sites that pertain to alternator output and length of wire. If you have the specifics for my application, that would be appreciated. I haven't run the power wires yet, was hoping to tonight but rain may delay any progress until thursday. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: storm34
Date Posted: May-10-2010 at 2:56pm
Famous last words of previous passengers in my boats...."its a boat, its supposed to get wet"  ------------- |
Posted By: Hawktique
Date Posted: May-10-2010 at 3:09pm
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I'd follow that up with "You have feet, you can walk home!" ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: 8122pbrainard
Date Posted: May-10-2010 at 3:26pm
Josh, Here's the formula: VD = 2 x K x I x L divided by CM K = ohms per mil. foot I = amps L is length (both to and from the load) CM = circular mils. The charts you looked at, what's the VD % on them? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: 79nautique
Date Posted: May-10-2010 at 3:37pm
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A 2 gauge wire from the battery to the starter relay is an undersized wire. It should be 2/0 or 00 as Tim likes to express the gauge but they are one in the same. Using 2 ga wire leads to starter issues and welded contacts on the relay. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Hawktique
Date Posted: May-10-2010 at 3:46pm
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I miss spoke on the 2 ga comment, sorry fo that. Not sure exaclty of the size of wire on the factory battery, they are not being messed with. The only thing I'm doing is adding a second battery under the dash, and having both charge from the isolator. I think the main discussion was on upgrading the alternator wire, and size of the wire going to the new battery. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: 79nautique
Date Posted: May-10-2010 at 3:49pm
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what year boat? if your adding a lot of stereo stuff then your going to need to upgrade the alterntor as well, and if it's an older model with an external regulator it needs upgraded regardless. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Hawktique
Date Posted: May-10-2010 at 3:57pm
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1990. For now I'm just putting in a 300w sub amp on two 10's. When I do the mids and 4-channel amp, I'll upgrade the alternator/regulator for sure. I'm not planning on going "all out", just better than avg. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: Okie Boarder
Date Posted: May-10-2010 at 8:45pm
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Josh,
Something to think about that I am contemplating is how this battery will be charged. If you're charging off the alternator, think about how much engine run time you need to have to compensate for the drain you put on the second battery. Think about the dead time during the day when you're parked, draining the battery down. I'm still considering what I'm going to do long term on mine. This year I'll have two amps. One for the sub (150W RMS) and one for the tower speakers (450W RMS). Last year I could go out 2-3 times before the "house" battery needed a charge. I'll see what it does this year. Next year I plan to get rid of the sub amp and get a 5 channel (700W RMS) to drive the in-boats and sub. This year's time allowance on the battery will determine my next step. I'm considering the following two options... 1. Switch and VSR set up or isolator of some sort (Like you're thinking). 2. On-board charger and plug it in after a day of use to charge both batteries properly, including tending. |
Posted By: Hawktique
Date Posted: May-11-2010 at 11:11am
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Okie, I'm not sure if there is a "right or best way" to do this. A dual battery tender is what my buddy uses on his fishing boat and I did contemplate that Idea. I really don't spend any time "floating" with the engine off so I'm not too worried about recharg time on the acc battery. My approach was to have a comletely independent system that would function automatically. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: 79nautique
Date Posted: May-11-2010 at 1:52pm
if you aren't using the stereo while floating and it's only on when your under way (engine on) why do you need two batteries? seems stupid too me, If the engine is running the alternator is powering everything and the extra battery serves no purpose other than to add extra weight and use up storage space. I don't understand your locgic with this one. Now if your sitting in a bay chillin listening to some tunes then yea add the battery a perko switch and call it a day. Why make something simple complicated? the alternator is more than enough to charge both batteries even if one is drained. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Hawktique
Date Posted: May-11-2010 at 2:31pm
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79,
I should have said "much time" insteady of "any". Now it may not sound stupid. I will not rule out the possibility of anchoring down and letting the kids swim a bit. I may even find myself on a sand bar/floating some time with friends and jam out. I want it set up for the possibilities. Installing a second battery and connecting through an isolator is not complicated. A perko switch on a second battery is just about the same price and amount of work to install. Not to mention that you want matched pair of batteries on a perko system so the weak one does not kill the strong one, which would mean buying two new batteries. I got all my materials from a very good friend of mine who owns a Baja/Crownline dealership. The only thing he charged me for was the $40 isolator because he had to order it. I want the isolator so the switching is automatic. My logic is that it's never a bad thing to have the extra weight of a second battery. I can easily modify the system in the event of either failing. Plan for the worst, hope for the best. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: 8122pbrainard
Date Posted: May-11-2010 at 2:47pm
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Josh,
FYI, CQ put a dual purpose battery in his boat and trust me he does plenty of floating around, music on, creating empties he can stick on duck decoys beaks!!! Are you sure you're not just going for the "bling" factor here? You've been spending too much time over on PN!  ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Hawktique
Date Posted: May-11-2010 at 3:03pm
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I really don't think I'm blingin it out much. This is not a blaster system by any means. Pretty much everything will be hidden and never be seen after I get the panels back in. I haven't spent much time on the PN site. From what I see and hear, I'm probably stuck somewhere in between the two generations. I'll have to check it out a bit closer though.
I'm guessing you vote no on the million color underbody kit under the gunnel? ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: 79nautique
Date Posted: May-11-2010 at 3:05pm
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I used a singal group 32 battery and jammed all day long at the sand bar and never had an issue. If your running bank of amps then you could use the extra batttery, I prefered to install High end speakers driven by an amp with the proper continuos watt rating for the speakers at max volume and never looked back. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Hawktique
Date Posted: May-11-2010 at 3:13pm
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That's the same thing I did with my truck! My problem is that I work on aircraft electronics all day, and sometimes sit here engineering projects I want to do while watching an auto test station for 1/2 of each day, and the fear of being "that guy" who drained his battery(I really just don't want to hear the wife complain if it ever happens). Worth the time and $$ for this guy. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: 79nautique
Date Posted: May-11-2010 at 3:30pm
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I here yea, all I ever did was fire up the boat for 10-15 minutes if we had been out there for quite some time as a safty precation, but the larger battery I had really didn't need to be charged but I did anyway to be on the safe side, but what I had you just can't walk into any store and pick one up. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Keeganino
Date Posted: May-11-2010 at 4:11pm
That is pretty funny. Right there with you being stuck between the generations. I am trying to restore and not rebuild a 73 skier, but if it does not change the appearance who cares! I am adding a second battery, a stereo and seat heaters. None of which can be seen. I do a lot of chillin with the engine off and don't want to explain to the wife why we are stuck on the lake because you cant run the stereo while you sit for a couple of hours and swim. Maybe overkill, but worth it to this guy too! ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: Okie Boarder
Date Posted: May-11-2010 at 4:19pm
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Josh,
Sounds like you have it figured out for what you want, which is the key. I'm still undecided on mine, like I said. I'll see how things go this year. We usually run in the morning, sit mid day, then run again in the evening, so I'm not sure if the alternator could recharge the battery enough or not. |
Posted By: Hawktique
Date Posted: May-11-2010 at 4:55pm
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Oki,
I'm sure whatever you decide will work just fine. Those on board charger/tenders are pretty slick. My buddy has a 2 bank system on his boat, ran him about $100 for the charger alone. He eventually installed an isolator for charging while underway. Some may see it as a waste, but he can now have piece of mind that both batteries will charge while underway, and also easily charge/maintain the batteries while not in use. I have thought of doing the same for the battery maintenance function... maybe before winter. Again, my history of being an electrician on helicopters for the good ol USMC has made me a fan of redundant systems, even if they are seldomly needed and a PITA to install. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: 79nautique
Date Posted: May-11-2010 at 6:20pm
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you know a jump pack will work just as good and is a lot easier to package in the boat's storage locker too. Trust me we've drained the house battery on the sea ray more than once and the perko switch as always isolated the starting battery, but that's and all day and late night party draining the batteries and I just don't see that type of drain on a ski boat for an afternoon with a simple single amp set up. Also the part about the batteries having the same charge or type when used with the perko switch is BS, that only comes into play if you leave the switch set to both all of the time, use the switch for what it is ment to be used for switching from one battery to the other, Start out with it on the starting battery, when you float and jam out, switch it over to the house battery, try and start the boat if it starts great if it doesn't then switch to the start battery and once it's started switch back over to the house battery and charge it back up, We've only used the switch on the both setting once when both batteries where pretty old and nights worth of bomber and after that we went to the marina and got new ones. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Hawktique
Date Posted: May-11-2010 at 6:42pm
Contradiction of sorts. Can't be BS if the issue comes into play. Any time the perko is in the all position, the two batteries are connected in parallel, the weaker one will affect the stronger one in some way. Probably not a major issue, but true. I still don't believe a perko is the most convenient way to do it. Leaves a lot of room for operator error. Perko's work, isolators work, single dual purpose work. The only thing that matters is personal prefference, and application at hand. We can drink whiskey straight, on the rocks, or mixed, at the end of the night, we're all drunk. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: 8122pbrainard
Date Posted: May-11-2010 at 7:36pm
My mistake-they were goose decoys and not duck!!  ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Okie Boarder
Date Posted: May-11-2010 at 8:41pm
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Josh,
So right...just depends on what you want and how you want to do it. I do like the battery maintenance aspect of the on-board. Pete, That picture is hilarious! |
Posted By: 8122pbrainard
Date Posted: May-11-2010 at 9:06pm
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Andy,
That picture is out of CQ's thread with his fight with the hunters on his lake. Evidently the hunters don't like skiers late in the fall!! Personally I think the hunters need to go after the tubers on CQ's lake. He has problem with them too just as many of us do!! BTW, they look like Coors lite cans so I suspect there was someone else involved with that "caper" too!!  ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: how much air
Date Posted: May-21-2010 at 2:31pm
| Don't bother with a crappy $40 isolator. Get a POWER-GATE that way you don't have a voltage drop to deal with, and you don't have the equalizing of the batteries like when a VSR connects a totally charged battery to a totally dead battery. |
Posted By: Hawktique
Date Posted: May-21-2010 at 3:10pm
The isolator I have was $40 my price, $100 retail. The same thing used on ambulances and other commercial/industrial vehicles. It does not connect the batteries together. It uses diodes (which are like one way valves for electricity) which only allow current to flow one way. It is not like a relay which would just connect them whith an applied voltage. Very simple design, and diodes only drop .6 volts. I agree that there are many ways to do it. This is one, and it works well. ------------- "A Veteran is someone who at one point in his life, wrote a blank check made payable to: 'The United States of America,' for an amount of 'up to, and including his life." Semper Fi |
Posted By: 8122pbrainard
Date Posted: May-21-2010 at 3:24pm
No name, I did a on line search for "power gate" and couldn't come up with anything definitive. How about a link and some details/specs on it so we can take a look at it? Then, we'll have something to go by to your claim regarding the "crappy" system. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |