So I want to add a second battery...

Post by Pj » Wed Feb 25, 2004 10:26 am

What are the min that I will need to get things working correctly?

This will go in a 1997 Chev K1500 Suburban. It already has a 2nd factory battery tray, no cabling.

Is it just as simple as adding in a 2nd yellow top and hooking + to + and - to - or...?

Not looking for anything elaborate.

Tom in D.C. · Post by **Tom in D.C.** » Wed Feb 25, 2004 11:33 am

Pj:

I believe that JCWhitney used to catalog simple systems to do this type of thing. It's probably commonly available at parts houses.

If I recall, what it did was to allow switching for A or B, A + B, etc.

Regards,

JohnWayne · Post by **JohnWayne** » Wed Feb 25, 2004 1:10 pm

I have used Hellroaring isolator systems in the past and really like them. Their website is http://www.hellroaring.com. They are a bit pricey, but the systems are deluxe and give you great control over the configuration.

You can just set the batteries up in parallel and basically make one larger battery. I really don't recommend this method. There are a few much better ways depending on what you are running and if you are doing it with the engine off for extended periods of time. The basic idea is to have one of the batteries isolated from the high amperage loads so that you can start your vehicle after running the accessory battery down.

What I would recommend doing is getting a deep cycle battery. An Optima Yellow or Blue top would work. You said you have a Yellow Top now. I don't think the Yellows are really reccomended for starting applications, but I could be wrong. Anyways, get your battery for the accessories and put it in the tray. Use a diode to isolate the two batteries, and electrical systems, from one another. This will let you charge both batteries, but only use your starting to start. It's generally a bad idea to start from deep cycle batteries, and to deep cycle starting batteries. You can get a diode from most RV supply places or off of the internet. Another good source is Wrangler Northwest at http://www.wranglernw.com.

That is it in a nutshell. If you decide to this I can go into greater detail about how to wire everything up.

Jeff

SlimBob · Post by **SlimBob** » Wed Feb 25, 2004 2:08 pm

don't forget to check out bluefeather's setup... w7com?

ASTROMODAT · Post by **ASTROMODAT** » Wed Feb 25, 2004 2:38 pm

I believe that GM used to sell a factory conversion kit. That would be the best way to go to ensure full compatibility, etc. Sounds easy, but there is a lot more than meets the eye in terms of adding a second battery!

Larry

JohnWayne · Post by **JohnWayne** » Wed Feb 25, 2004 2:40 pm

If GM is like Dodge, then yes, you can get a kit that has the tray and cables for the second battery like you would find a diesel truck. If this is your end goal, then the factory kit is definitley the way to go.

Jeff

jim · Post by **jim** » Wed Feb 25, 2004 4:12 pm

An isolator WILL NOT add an reserve capacity. You are merely separating a vehicle battery from accessory battery and not doubling capacity with one of these. Great for RVs or boats...useless for just about all other applications. Doing a true parallel setup will double your available crank power and double the reserve capacity.

If you have the Optimas in a GM with side-posts, just crimp/solder/shrink top-post terminals onto a pair of red and black #2 cables and jump the Optimas.

Use "snake" loom over the pair and shrink-tube the ends so it deosn't move. Now cover with split loom. I run them from the stock location back to the firewall then across to the #2 location. Clamp to the firewall securely.

Note: if you have a habit of running these batteries "low" constantly, you might want to bump up the alternator rating and install a new #8 (or #6) alternator-to-battery lead with the proper fuse link inline.

JohnWayne · Post by **JohnWayne** » Wed Feb 25, 2004 4:17 pm

If you want reserve capacity, then you're right, an isolator doesn't do much good. However, if you run your equipment for long periods of time without the vehicle on, then it WILL save you from a dead battery.

There is about 10 ways to the dual battery thing, and I've done them all. It really just depends on what your end goal is.

Jeff

kc7gr · Post by **kc7gr** » Wed Feb 25, 2004 4:28 pm

SlimBob wrote:don't forget to check out bluefeather's setup... w7com?

Almost -- W7COM is Joe. He was a customer of mine at one point, which is how we got to know each other.

The link showing my own dual-battery setup (I used an Optima Yellow Top for the aux unit) is at:

http://www.bluefeathertech.com/kc7gr/thevan.html

Note that some of the pictures are a little out of date. I no longer have the black StarTAC cellphone (been replaced with a T730 and different mount), but I've not had a chance to update the pics just yet.

Post by Pj » Wed Feb 25, 2004 4:56 pm

Thanks Jim. What I am looking to do is add reserve while keeping a good supply with all the equipment going with the vehicle running.
At some point I am will be upgrading the alternator. There are times in which I will have the radio's on for an extended period of ttime, but the lights will be off with the vehicle.

ASTROMODAT · Post by **ASTROMODAT** » Wed Feb 25, 2004 5:27 pm

The GM factory conversion kit is NOT a tray and cables!! It has a TON of stuff! There are all sorts of interface cables to the electrical system that go WAY beyond a tray and cable! That's my entire point---it is WAY more than "just adding a second battery, some extra cabling, and a tray." Check it out with GM. There are probably several dozen parts involved. When it was available, it was well worth the price, too, but I'm not sure if it's still available for such an old rig.

Larry

jim · Post by **jim** » Wed Feb 25, 2004 8:24 pm

To clarify things in the world of GM.

There are two GM options for second battery.

#1 is the OEM Diesel setup, which is just two batteries in parallel. Nothing fancy- just a jumper pair that will give you true double power for cranking the oil burner on a cold morning.

#2 is the "RV" equipment option, which includes an isolation solenoid, fuse link from starter, 100A wafer fuse and holder and a cheesey #10 charge lead to the second battery. This also has a small fuse to power up the solenoid.

Stay away from #2 by all means! This is stricly for running RV lighting without running the battery dead and offers no additional reserve. It has a VERY small charge lead, too. It was made available for those who tow a housetrailer or other trailer with lighting that runs without the engine running. With the engine off, the solenoid disconnects battery #2 from the rest of the truck. When you turn the key on, the battery connects again to charge.

If you have a truck with the second type system and you need BIG power, dump the controls and add a true parallel #2 pair to battery 2.

To my knowlege, Mopar nor Ford uses a "floating" type second battery like the GM RV system.

apco25 · Post by **apco25** » Wed Feb 25, 2004 9:50 pm

all the GM diesels and heavy duty package I've seen with dual batts were simply that 2 batteries with the heavy jumper cables. Simple and sweet.

Its on the list of upgrades for my truck.

RadioSouth · Post by **RadioSouth** » Thu Feb 26, 2004 9:54 am

Years back I had a Tahoe Diesel. Batteries were parallel wired as mentioned. To add flexibility I added a simple on/off switch to each batteries B+ wire. This way I had the flexibility to run both for those cold starts and could use A or B for running the radios with the ignition off.
And you could always kill both if wanted for minimal theft security or while
working on vehicle.

ASTROMODAT · Post by **ASTROMODAT** » Thu Feb 26, 2004 10:21 am

Best bet: Buy a new Suburban, and make sure to order the "Dual Battery" option. Order a new XTL 5000 at the same time.

Larry

SlimBob · Post by **SlimBob** » Thu Feb 26, 2004 11:34 am

If you're after GM OEM parts, you can locate them on GMPartsDirect.com, ore try Dal Slabaugh of Van Devere Olds in Akron, OH. He tends to cater to car clubs and the like and can get most GM parts for cost + 10% + shipping. As they discontinue parts, he looses them too as stock depletes. [email protected]. I get all my parts from him (that I can / can afford to); just bought a transmission from him as well (GM SERTA reman for my 95 Caprice).

jim · Post by **jim** » Thu Feb 26, 2004 3:48 pm

If you order a single battery GM with the "dual battery option", you will get the RV/towing system with a solenoid and #10 charge lead.
Useless.

ASTROMODAT · Post by **ASTROMODAT** » Thu Feb 26, 2004 4:08 pm

Better yet, order a Ford Excursion with the Power Stroke 6.0 L diesel and dual batteries. Don't forget the XTL 5000.

Larry

wa2zdy · Post by **wa2zdy** » Thu Feb 26, 2004 6:41 pm

Jim,

You say stay away from #2. But that may be what some want. It's what I'd want.

In situation #1 you have two batteries in parallel. They will last longer, but in the end, leaving things on will just run both down and you're still stuck without a ride.

#2 lets you leave things on and not worry about it. The radios and whatever else you have on battery two will only run it down, leaving the main battery charged to start the car. I think that's more useful for most of us with our toys and gadgets.

apco25 · Post by **apco25** » Thu Feb 26, 2004 6:43 pm

anyone have the part number for the dual battery kit from GM?

That site won't find it without a part number

jim · Post by **jim** » Thu Feb 26, 2004 9:11 pm

If you choose #2, keep some spare wafer fuses handy. If you run the battery very low and start the engine, the aux. battery will pull a very heavy charge and sometimes pop the wafer fuse (under the aux. battery tray). It might be a good idea to eliminate the wafer and install a Buss or TST waterproof 100A auto reset breaker in its place.

chipjumper · Post by **chipjumper** » Sat Feb 28, 2004 1:51 am

I have the exact same burban and have the same dilemma...

Now, if I have a dual battery setup using an isolator that means that if I leave electrical accessories on overnight and they burn out a battery, it will only discharge the battery it is hooked to?

Isolator deal sounds like a safer plan...

Deep cycle battery good for accessories battery (2nd battery)???

jim · Post by **jim** » Sun Feb 29, 2004 7:46 pm

For an isolated #2 battery, the deep cycle is good. Make sure it can take a hard charge. Some DC batteries can only be trickled, which an alternator will burn out.

So I want to add a second battery...

So I want to add a second battery...

2nd battery installation...