Well, it happened again, someone left the lights on (not naming any names now, but there's only 2 people that drive it :-) ).
I can't blame her, I've done it myself.
So, next project for my truck, add a relay so the headlights turn off when the truck turns off, and install a dual battery system (I've always wanted that anyway, this is a good excuse as any).
So, I picked up a Optima Red top from Costco for a whopping $100 (on the cheap side for these batteries from what I've seen), and I got some battery "tie downs" from the 3 idjits (pep boys), now I need to figure out wiring.
Anyone know of a good diagram to go by?
I've seen some on the 'net where I could 'flip a switch' to jump start the main battery from the aux, just there weren't any diagrams on how to wire for it.
That's kind of what I'm going for.
Thanks for any advice/help!
Todd

 

Search through this thread: https://www.yotatech.com/forums/show...691#post113691

I threw up a couple of links with diagrams and info on dual battery options.

Actually though, if you dont need the power, you dont need to go dual batteries now that you have an Optima. They are self charging. If it dies, just unhook everything and it will charge back up. Takes like 5 mins.

 

For a dual batttery system in a truck isnt it wired up just like a dual battery in a boat. A switch with off, 1, 2, both. I'm thinkin bout doin this when i get my winch, that way i will have a little more power. Gonna figure out a way to mount the battery down low, like make a mount tht attaches to the frame rail.

 

I've got mine hooked up with a little device called a battery combiner, available at West Marine. Charges both batteries from one alternator but won't let them drain into each other if one is dead. Also have a switch to combine them when using my winch, and soon I'll have a switch to convert them to 24 volt for use with the welder I posted about in another thread. Wiring depends on where you mount the second battery, but is pretty simple. I could describe it if you want but I don't have software to draw a diagram as my computer died and I'm using a loaner right now. In response to the statement that Optimas are self charging, that's a bunch of crap, there is no such thing. They are an AGM type battery (absorbed glass matt), which means they can give off a very high amperage discharge like needed for starting or using a winch, and will read low voltage afterwards, and then show the voltage come back up after sitting for a bit, but it's just the way the battery works. It doesn't recharge its self, it just doesn't read correctly on a voltage meter until it's had time to sit, but the voltage is still there. As they say, you can't get something for nothing, you have to have a charging source to put energy back into a battery. Anyway, let me know if you want a wiring description.

 

I guess they are not truely self charging, but there is something in the spiral model that enables you to start up if you turn everything off and unhook everything. I kill my dual battery setup all the time on camping trips. I merely unhook everything, turn off all my accessories, let sit for 5-10 mins, and she'll start up no problem. I guess if you completely drain your battery, you are out luck, but usually there is enough to get you going, but it has to be used correctly. I dont know enough about the internals of the battery, but I know what I experience. 2 dead batteries, on is a read top and the other is a yellow. Unhook everything...wait...fire up.

I guess its like a battery in your tv remote. It dies, but if you wait a few seconds, you can hit the button again and the channel will change. But then you have to wait another 20 seconds. I beleive optima harnessed this ability to give you that one last start to get you going again.

Here is those diagrams: http://www.eatel.net/~amptech/elecdisc/battiso.htm

And here is a bunch of info on alternators: http://www.eatel.net/~amptech/elecdisc/charging.htm

 

If you don't mind, what did the combiner cost you?
I'd be interested in how you wired it, a description as best you can will do.
I'm fairly good at interpeting directions, but as usual, pictures are better
Eventually, I'd like to do the welding thing as well, and this would be a good step forward for it.
Battery location would be in the drivers side where the "resonator" air box was (carb engine). About the same space as the standard battery location on the pass. side.

Thanks!
Todd

 

How does this look for a wiring schematic?


It was taked from guestco.com .
Looks like a decent possibility.
Any thoughts?
Thanks!
Todd

 

Mine is wired similar to the Guest diagram you posted. Instead of a 1-2-both-off switch, I just have an on-off switch, rated at 350 amps, connecting the two positive terminals. I think I used 2 gauge wire. The switch is left in the off position unless the original battery goes dead and I want to boost it with the charge from the second battery, or if I'm using my winch where I want as much capacity as possible. This way the truck always starts using the original battery. My fog lights, off-road lights, the lights inside the topper, and my accessory outlet are all running through a second fuse box I wired into the second battery. The combiner is wired between the positive posts on the two batteries, where the isolator is in the Guest diagram. It works by sensing voltage, and opening a circuit between the two batteries after the voltage reaches a certain level, usually around 13.8 volts. This way the original battery is always charged before you begin charging the second battery. I think the combiner costs around $50. An isolator will cause a voltage drop, and your alternator will never fully charge either battery when wired like that shown in the Guest diagram.
Hopefully this all makes sense, and feel free to ask for more info or clarification.

 

By the way, if you think you will want one of the welders you should let me know now. The buy I do on these will most likely be a one time only deal at this price.

 

Couple of things,
Which amp rating did you get on the combination unit?
West Marine has a 50 amp and 150 amp versions (I'm going for the 50 amp, it's cheaper), but they were out of the 50 amp when I went this evening, of course. I'll have to try another store tomorrow.
What's the cost of the ready welder you're going to get?
If possible, I'll try to scrape together enough $$ to do it.
Thanks!
Todd

 

I used the 50 amp combiner. I still have a stock (55amp?) alternator on the truck so I didn't need the bigger one. 100 amp alternator or bigger and I'd go for the bigger combiner. The welders will be $379 plus shipping. PM me if you want one, or if you have any more questions on the battery hook up.

 

Here's my Dual Battery Installation, I used a 200A continuous duty solenoid to connect the two. Has worked flawlessly for the last 5 years or so.