FAQ addition: Dual Battery Set-Ups (4 Viewers)

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I like the way you did the switch/led in the cab. I may copy that with your permission! Looks like a clean install.
 
Nicely done Ken. As I mentioned in another thread, I also copied CruiserDrew's Hellroaring install.

It meets all the criteria... Exceptionally low voltage loss, automatic, easy to operate and much, much cheaper than the "perfect" alternative that I won't mention. The owner of Hellroaring is a guy named Mike and he is also who I spoke with when asking questions. He is knowledgeable and not pushy at all.

All in all, this is a great alternative for those seeking an inexpensive and bullet-proof dual battery system. Just follow Andrew's install notes and you'll be good to go. He even gives cable lengths, wire sizes, and sources for all the bits and pieces.

-B-
 
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Hey B...I know you still have a burr over the whole Powergate pre-sales info thing but I gotta tell ya mine works great. Yes it costs a little more but it's significantly smaller (which has made a difference in my engine bay with everything I have stuffed in there) and virtually no heat-up...which tells me the darn thing is working pretty efficiently and no mechanical connections (other than the battery cables of course ;) )


Just another perspective...
 
spressomon said:
Hey B...I know you still have a burr over the whole Powergate pre-sales info thing but I gotta tell ya mine works great. Yes it costs a little more but it's significantly smaller (which has made a difference in my engine bay with everything I have stuffed in there) and virtually no heat-up...which tells me the darn thing is working pretty efficiently and no mechanical connections (other than the battery cables of course ;) )


Just another perspective...

Do a write-up on your system and post it here. This is an FAQ thread and I don't want to get into the same discussion we have had in other threads.
 
OK. I know that this doesn't have a lot of finesse. It is, admittedly, an overkill brute force dual battery install.

The first thing you're likely to notice is that there are two big ass marine switches. These are rated to 1200 amps for 30 seconds each. They're also radioactive. The dials are black lettering on a Tritium background. Pop the hood at night and they're two ghostly circles.

I custom bent the switch mounting bracket and brace using 12ga galvanized steel and a 100 year old brake. It fits -barely- -at an angle- where the horn used to mount.

Yeah, I have more work to do on the horn. I'm wanting to put in something nicer than factory. Unfortunately, all of the auto parts stores here sell the exact same crap for aftermarket horns, and they're all plastic shelled junk. If anyone has a line on high quality LOUD horns, I'm all ears so to speak. I'll be relocating them regardless. I had room for one of the factory horns, so I left it in for the moment. Sounds pathetic though.

The batteries are both new Optima D31a Yellow tops. Each one has 1125 CA @ 32 F. So, if you think about it, it is more like a quad battery install...

The left battery tray is new and is the part for a 1992 FJ80. I got it and the requisit bracket & J hooks from www.toyotapartsdealer.com. That was before I knew about Dan or this website.

The water bottle is on a Slee relocation kit.

The cables are stout. They are Ancor Marine tin coated copper 2/O battery cables. These 'double ought' cables are a bit of a bitch to work with. They bend, but those 180 degree turns you'll see on the bottom of the switches were a trick.

All 4 terminals are mil spec with 5/16" bolts.

The cable lugs are Ancor Marine tin coated copper and were put on with an impact crimper tool. All lugs have heat shrink. I've tried to put reinforcing looms on the cables where they might rub.

The left switch runs the winch load. When I get around to it, I also plan to run a fork lift charger connector out the front and connect it to this switch as well. This will be my 'jump start anything' port as well as 12v DC power to whatever I want from the front end.

The right switch runs the house load. The output from this feeds back over the top of the DS battery to the (+) bus stud mounted to the back side of the DS tray using stainless steel fasteners.

The (-) bus stud is on the back of the DS tray as well. Both batteries and the winch ground to this point. The batteries ground using OO tin coated copper marine cables as well.

The Warn M12K is opperational now and no longer the worlds most expensive license plate bracket.

Next steps?
1. Circuit protection. I realized after I finished the install that although there is protection via fusible links for the house load, there isn't anything on the winch load OR on these cables I have. If one of these monsters grounds out it will weld pretty quickly with these batteries. So, the plan is to put a 300 amp fuse in line between the cable lug and the mil-spec terminals. They're on order.

2. Get new horns and mount them somewhere new. Whats the opinion on using train air horns mounted inside the ARB?

3. Run a pair of cables from the house buses back through the firewall and to the pannel where the factory sub is. I have a lot of toys in mind that require electricity back there. Yeah, 1 would be power, but I'm big on making sure that I have adequate ground. Body grounds are fine for lights. For anything over a 15 amp load, I want a direct to battery (or near so) ground if I can get it.

Fun fun. Next posts are the pictures.
 
Pics 1

First set of pics....
IMGP1307.jpg
IMGP1308.jpg
IMGP1309.jpg
 
Oh, the little red bows on the optimas are actually tubular webbing tied around the battery and knotted with a water knot. Although not as heavy as the type 27F batteries I had in it, these are still heavy batteries. I wanted handles to be able to get them in and out.
 
Grench said:
Oh, the little red bows on the optimas are actually tubular webbing tied around the battery and knotted with a water knot. Although not as heavy as the type 27F batteries I had in it, these are still heavy batteries. I wanted handles to be able to get them in and out.

Grench,

Can we get a schematic? There's a lot going on there.

Thanks,

T.
 
I can't draw very well... ANSI art

OK, I don't know if this will work/show up right, but what the heck. The whole thing started with a sketch on the back of a napkin and I've never built a formal schematic for it. Its pretty basic though. For the off chance of making it legible, I'll keep this as simple as possible.


Here's the basic idea.
schematic_basic.jpg
 
Can't you put the two batts on parallel? I thought that you could! if not, why?
 
Yes, you can parallel 2 batteries. That is what the above diagram illustrates.

-B-
 
Beowulf said:
Yes, you can parallel 2 batteries. That is what the above diagram illustrates.

-B-

Ah!! now I understand the diagram!! thanks!
 
Yes. The marine switches (scroll back to the picture) have 4 settings. Up is off, turn it to the left and it is battery 1 which is the DS battery. Right is battery 2 which is the PS battery. Yeah, the left/right feels backwards when looking in the hood. Turn left to get the right battery, etc... I wired it considering 1 as primary and I wanted to keep the logical primary one in the stock location.

There is a 4th position on the switches that doesn't come into the phot because of my very tight install. Straight down is 'both' and puts the system into parallel.

If either switch is set to parallel and the other switch is not off, then the whole system is in effect in a parallel mode.
 
Newbie Question for you guys

Yes I have searched this forum for my answer and haven't found it.

Why do you guys mainly run an isolator or selonoid for your dual battery setups. Why don't you run dual alternators???

What are the benifits other than costs ???

Thanks
 
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Sami,
A battery stores energy; an alternator produces energy "real time." The objective for a dual battery system is to enable you to run down one battery without running down the other. A dual alternator with a single battery wouldn't help with this objective.

A dual alternator; each with it's own battery to keep charged up is another solution, and probably what you are suggesting. The main reason that I wouldn't do this on an 80 is that you would have to fab up alternator mounting, pulleys, belts, tensioning device, and acquire a 2nd alternator. This is spendy. The stock 80 alternator has enough capacity to keep 2 batteries fully charged and the stock alternator is reliable. If you are going on an extended expedition then a spare alternator would be something to consider.

A friend of mine with an FJ60 had dual batteries charged by dual alternators. This was an easy project on his 2F engine because he simply replaced an air pump with an alternator. Brackets, belts, tensioner, and all that stuff was already there so all he had to do was wire up the 2nd battery and run some accessories off of it. I don't recall how he would handle jump starting unless he wired the starter to both batteries. Maybe he had a marine switch for this purpose?

-B-
 
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One other reason is that with dual batteries, dual alternators, but no solenoid you would have two completely isolated systems. You'd lose the ability to start off of either or both batteries, winch off of either or both, etc.

There are definitely advantages to having a second alternator for charging, but there are just as many advantages to being able to combine the batteries when you need to.

I think the best solution would be to have dual alternators and dual batteries, while maintaining the switching to combine or select the batteries you want to use.

You'd also want to be able to disable the 2nd alternator if you haven't been using your 2nd battery. I've found that I go weeks without charging my 2nd battery, because I'm trying to avoid cooking it if I haven't been draining it.
 
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samis said:
Newbie Question for you guys

Yes I have searched this forum for my answer and haven't found it.

Why do you guys mainly run an isolator or selonoid for your dual battery setups. Why don't you run dual alternators???

What are the benifits other than costs ???

Thanks

Actually I don't. I'm the weird one in this though. I have full OO cables running through and dual switches. If I had to do it over again I'd lighten up on the cables to 2ga instead of the OOga. Those were expensive and a PITA to work with.

I've since put 300amp marine fuses right off the + post on each battery. I have spares in case the winch blows one and can bypass them if I feel a need.

I've also solved my horn delima with a powder coated stainless steel Oringo marine horn mounted on the ARB support bracket. I'll see if I can get a picture of the fuses and one of the horn placement onto this sometime this weekend.
 
Hmmmm interesting discussion.
Frankly in my eyes the biggest and ONLY disadvantage is the cost of fabrication/second alternator. For someone with extensive loads on their second battery this would be an ideal arrangement with no downside except perhaps the ability to combine batteries easily (note I did not say it isn’t possible you would be amazed what can be done in the rare cases where you might need to).

No offense but I am really curious about all you guys that have built complex systems with the ability to self-jump…how often do you need to do that??? Frankly if this is an issue for you; your energy would be better spent figuring out why your primary battery keeps going dead. :rolleyes:
Seems kinda like preparing for hurricanes when you live in Nebraska.

My simple isolator set-up provides no built-in means to combine my batteries. Does this mean I’m out of luck if my starting battery is dead….no. Let me share some information about some fantastic technology….. a set of jumper cables. (BTW in 22 yrs of dual battery systems I’ve never had to self jump…but I can :D )
 
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