Accessory Battery Question....

[Greg5567]

Im curious as to how this is going to work, if I have a WARN 8k Lbs Winch, and say 8 off road lights and im using a separate battery for the accessories and another for starter, would the alternator for the starter ALSO charge the accessory battery or could I have 1/1 for accessories and 1/1 for starter

 

[Shran]

Connect them in parallel and leave your wiring somewhat intact. Here is a basic idea of what you want to do, second drawing:

http://www.zbattery.com/Connecting-Batteries-in-Series-or-Parallel

 

[holyford86]

I would recommend staying away from wiring your batteries in parallel, I would run an isolator and keep the batteries as two nearly separate systems. Batteries in parallel tend to feed off of each other and they will both go dead if both batteries aren't identical in size and condition. isolators arent that pricey either and they aren't that hard to wire.

 

[Greg5567]

I would recommend staying away from wiring your batteries in parallel, I would run an isolator and keep the batteries as two nearly separate systems. Batteries in parallel tend to feed off of each other and they will both go dead if both batteries aren't identical in size and condition. isolators arent that pricey either and they aren't that hard to wire.

I was looking at those earlier, would I be able to have like an On/Off switch on my Accessory battery and just pretty much flip it on, and use them, and off so it doesnt drain?

also

Will my alternator charge BOTH batteries or would I have to get 2?

 

[Shran]

Parallel is fine. My camper came wired in parallel for two batteries from the factory and it works great. Just make sure the charging system is in good condition.

Batteries aren't really something to cheap on. It's a good idea to have the same size and condition batteries, and not just because the article above says so.

 

[Dishtowel]

Wire them in parallel, just include a battery disconnect to your second one and wire your accessories to it. Your not going to use them all the time I imagine? Then at the start of a trip when you want to charge everything you can pop the hood and include your second battery. After you have driving for (approx) 1-3 hours it will be fully charged. Then pop the hood and disconnect it, you now have a full second battery only a switch away for when you need it. I want to do this for my rig for times when I have lots of winching to do, or heavyheavy pulls. Then my limiting factor will be winch heat instead of power. (Perhaps I should rig a small electric fan on the winch motor?)

You could replace the heavy battery disconnect with a serious heavy relay (get on rated high enough, and rated for CONTINUOUS duty, a starter relay is NOT rated for continuous duty) then you could switch your accessory battery from the cab.

 

[Greg5567]

Thats kinda the setup I wanted..

1 Battery = Starter
1 Battery = Accessories
1 Switch =On/Off for the accessories

I wasnt sure if my originial alternator would be enough to charge both at the same time, but im guessing if ALL i have rigged to 1 battery is accessories as long as they are turned off, shouldnt have any problems while the battery is on being charged.

 

[Dishtowel]

Thats kinda the setup I wanted..

1 Battery = Starter
1 Battery = Accessories
1 Switch =On/Off for the accessories

I wasnt sure if my originial alternator would be enough to charge both at the same time, but im guessing if ALL i have rigged to 1 battery is accessories as long as they are turned off, shouldnt have any problems while the battery is on being charged.

Your charging system will do it.

What i described is not a system that leaves the starter independent from the accessories. If you park your truck with the accessory battery enabled and leave the lights on you will not have juice to start. If you park your truck with the the accessory switch off and the lights on you WILL have juice to start your truck. When you have the accessory battery fully charged and you want to power ALLLL your lights and the winch you will be able to do it for a bit with out anything handycapping you. Study electricity, 11th and 12th grade physics I think. It's a good thing to learn.

If you infact have more watts OUT than watts coming in from your alternator, this second battery will make the situation last way longer.
EG watts out 200/hr, watts in 100/hr. 800 CCA battery (800 x 12 volts = 9600 watts) your battery will last approx 96 hours this way
VS
watts out 200/hr, watts in 100/hr. TWO 800 CCA batteries (192 watts) should last double as long.

This is just a ROUGH estimate. it just gives you more capacity, thus a larger buffer to get the job done, or get home, or whatever

 

[Greg5567]

I think im understanding it a little, not to sure. The way im thinking seems easier, and maybe a little more practical, although im sure its cause you actually know what your talking about and im taking a shot in the dark sorta...

So, I really dont even need the 2nd battery....I mean if I have a switch for my winch AND lights. Say its bright as day, and I only need to use my winch, I could flip it on, use it, and turn it back off once im done, without having to turn the lights on and drain aswell...or if its dark, and im not using my winch, I can have my lights on only, and I doubt ill be driving for anywhere near 96 hours with my lights on lol...

 

[Dishtowel]

Say its bright as day, and I only need to use my winch, I could flip it on, use it, and turn it back off once im done, without having to turn the lights on and drain aswell...or if its dark, and im not using my winch, I can have my lights on only.

There has to be a minimum of 3 switches.
1st switch includes/isolates your second battery, this does not turn the light+winch on, it just allows your charging system to charge your second battery.
2nd switch turn your light off (they should have their own relay)
3rd switch is a toggle to operate your winch.

i encourage you to do some reading/homework on this stuff, you'll learn lots. I can't effectively explain stuff without diagrams, lol.

 

[Greg5567]

What you just said was what I was pretty much trying to get at the whole time, but after reading what you said it kinda made it seem like I didnt even really NEED the 2nd battery. Figured I could just buy a beefed up alt and keep the battery I have in there now since I most likely wont be running BOTH for long periods of time, or either one period....for long sessions..

Yea, I definately need do some more reading on this before anything is purcahsed/installed..

 

[Shran]

You don't need the second battery if you're running the winch and lights with the motor running. If the motor isn't running, two batteries will give you twice the usage time for accessories. Figure out what the power requirements are for all your equipment turned on at once and see if your alternator will handle it. Chances are it will.

 

[COPPERHEAD85]

i use an isolator has worked for me,had it when the v-6 was in the truck and had 2 batteries under the hood.1 for starting 2nd for acc.lights,3 amps,anything else i wanted to tack on.didnt have any problems with it........still have it.
when i did the 302 swap i moved the batteries to the bed and put in 2 27 AGM deep cycles.i also went with a gm 1 wire alt at 140 amps.motor running i get about 14.2 volts at each battery.
its easy to wire and like i said it works for me.some people dont care for this set up they run relays.

 

[Greg5567]

Yeah, I dont plan on running my lights/winch or anything without the truck on anyways, so im sure 1 battery with my alternator will be good enough, if not all ide have to do is replace it with a better one....im guessing..

 

[CopyKat]

I've got a 130 amp alternator and have been running a dual battery system, paralleled, for over 7 years. Not one lick of problem.

I used to have an isolator but parallel worked just as good.