Dual Battery Setup

[RRRAAAYYY2]

That's a common misconception. If you had 100 batteries, the starter & winch would get the same amount of current they did with 1 good, charged battery & good wiring. But if you run the winch continuously long enough to need 2 batteries, you're probably overheating the winch motor.

If you want something cheap, simple, safe, & effective, use the Ford system. It works. And you can add a switch to control the relay if you want (say, for jump-starting without opening the hood), but it'll do fine wired directly into any fused key-on circuit (like the gauges).



Note that there's a fusible link wire between the batteries, but I'd use a ~150A circuit breaker.

Actually if you wire the batteries together properly, there would be almost zero resistance in the 100 batteries, vs a lot of resistance in the single battery. So instead of a slow discharge of 600amps from the single battery, you would have instant amperage and no voltage sag in the 100 batteries. In a starter circuit the single battery would drop to 9.5volts, while the 100 batteries would likely stay well above 12volts. (That is 26% more voltage, which is 100% more power) So there would be tremendous difference between the performance of the two systems.

Again, the Ford system is designed to be cost effective, not the best way to do something. When it cuts the battery life in half, it is not "effective".

 

[RRRAAAYYY2]

Now thats what talking about! Just a knife switch in line ahead of the aux battery to just uncouple it if you want for whatever reason. I was thinking of a fuse too in-line ahead of the aux battery in the event of a short circuit condition on the winch. If drawing 400 to 500 amps at the time the in-line fuse would have to be at least that size or larger or possibly a circuit breaker that would handle the winch load. Thats what I'm thinkin' anyhowz.

Knife switch is a good idea for theft protection. But if you look at how to wire the batteries properly, if you break the line (knife/fuse/etc) between the batteries, the sytem should be dead.

 

[RRRAAAYYY2]

I rarely run both batt. at the same time, only if both are very low. So one being older shouldn't matter. I think the Hellroaring setup will work too, it automatically switches from one batt. to the other.

I did not see anywhere in their description of it doing that. It should also be noted that when they use diodes to isolate one battery from another, there is a .7-1 volt drop (lost). From their description they basically do the same thing as Surepower's Battery Separator, but at twice the price and some voltage drop.

 

[57bronco]

They are only continous duty, for which the duty cycle is 60 seconds, vs intermittent duty, which is 10 seconds. There is a continous duty prolonged on solenoid, that is available for use in applications over 60 seconds.

I've been using these for over 10 yrs and no problems. One of my Optimas is over 10 yrs old, the other is over 7 yrs. I don't see any reason to change. I think when I did my setup the solenoids were $14/ea.

 

[57bronco]

I do like the Sure Power 1315-200, especially for $102 off the net.

 

[RRRAAAYYY2]

I've been using these for over 10 yrs and no problems. One of my Optimas is over 10 yrs old, the other is over 7 yrs. I don't see any reason to change. I think when I did my setup the solenoids were $14/ea.

I can only give you the info, LOL. Your usuage habits or some times just sheer luck wins. But for every success, there are lots and lots of failures.

I do not doubt your system at all, and there will likely be others in the exact same situation. I just have to be correct, so when the next person doesnt get the same results as you have, doesnt get mad at me. Hope that makes sense.

 

[RRRAAAYYY2]

I do like the Sure Power 1315-200, especially for $102 off the net.

Hasd its little brotherr in some Civics that were just pounding systems, last longer than the cars. The stereos tore the bodies apart.

 

[57bronco]

I know a lot of EB owners that have the same setup I have, no problems yet. It is a normal setup on many upper end boats, they use a computer control to do the switching.

 

[57bronco]

This is off the subject, but about 12 yrs ago I met a guy with a EB that was electric powered. Has anyone on here known of this EB. He took it to Tellico, if I remember. He also worked or owned a electric drag bike, ran off sub c's.

 

[Steve83]

A starter that pulls 375A@12V will only pull 375A no matter how many 12V batteries it's pulling from.

I haven't observed any drop in battery life due to running them directly parallel, or any charging problem due to running one thru a relay, and that's over a few years of use that way.

 

[GrillMaster]

You will need to run the batt cab to and from the switch. With my setup, I have two toggle switches at arms reach.

That is not a problem. Is it ok to run on "BOTH" to charge one standard and one deep cycle? and then just switch to one when I run my stereo and lights with the engine off?

I have seen a locking switch which may make for an added theft deterrent.

or would I just be better off with a isolator?

 

[57bronco]

I'm running a stock 45 amp alternator on my 302, EB. If I have both batts low and turn both on, it puts a strain on my alternator.

 

[57bronco]

A good theft deterrent is a manual line lock, hooked to all four brakes.

 

[GrillMaster]

I'm running a stock 45 amp alternator on my 302, EB. If I have both batts low and turn both on, it puts a strain on my alternator.

In that case you could charge one then the other. Do you keep on "both" for daily driving and to keep both charged? If one batt is low with it harm the other one?

 

[57bronco]

I only run on one for everyday. I usually rotate the batt. use from time to time.

 

[GrillMaster]

I'm wondering if the charge with an isolator rather than a switch will prolong batt life.

 

[57bronco]

It would be simpler. I'm use to what I have, but I do like the Sure Power 1315-200.

 

[57bronco]

I have thought about going to a onboard welder with the large alternator and wonder if this will affect the Sure Power 1315-200

 

[RRRAAAYYY2]

A starter that pulls 375A@12V will only pull 375A no matter how many 12V batteries it's pulling from.

I haven't observed any drop in battery life due to running them directly parallel, or any charging problem due to running one thru a relay, and that's over a few years of use that way.

It will pull 375amps from one battery, or 3.75amps from 100 batteries. If it just one battery, the system voltage will not stay at 12volts, where as with only a 3.75amp draw, the 100 batteries would keep their voltage higher.

Also, just so you know, starters draw different amperages at different rpms.

As for battery life, because you or someone else doesnt see any loss, after a few years, doesnt really count. I have sold 1000's of batteries, and my firends many times that, to customers who had batteries that didnt live out their possible life cycle. I decently maintained battery is good for 10years, do it really well and 15 isnt hard. So if yours is 5 years old, it still has a long way to go.

 

[RRRAAAYYY2]

I have thought about going to a onboard welder with the large alternator and wonder if this will affect the Sure Power 1315-200

Depends what you want it to do. But should not. I think i know someone that has some old Hehr Power Ford large body alternators that they used for their welders. No regulator though. You could probably get the alternator for $150-$180 (they used to be $700+), they are new or have like 200 miles on them. Got swapped over to Ecoairs.