Non-factory dual batteries- Stock alternator?

n8huntsman · September 9, 2004

Im installing a 300 watt inverter to power a computer for dvds, navigation, mp3's, backup cam, usb xm radio, etc. Im going to use a dual battery system with a diode isolator. The batteries are the optima red tops. Will the stock alternator be sufficient to charge both batteries or will I need to change it. If so what should I change it too?

concours · September 10, 2004

nate, your OEM alt. will be fine. Batteries are only a storage device... the alternator will take X amount of time to replenish them, depending on state of discharge. A bigger alternator would simply shorten the recharge time. The OEM alts are pretty big nowadays, my '01 'Burban has got a 130A. Perhaps you'd be better with one red top for primary starting and one yellow top deep cycle for your secondary battery. The 300w inverter is rather small, and the battery should last quite a while. I've set this type of deal up on a few plow trucks that have a hydraulic pump powered by a starter motor sized electric motor. Combined with the heater, lights, auxilary lights it works great. Good luck.

Worktruck · September 11, 2004

Just curious as to where you are mounting the aux battery? I would like to add a extra battery to my 1/2 ton ext cab but not sure where to mount it. Any advice is appreciated.

MS3DALE · September 11, 2004

Just curious as to where you are mounting the aux battery? I would like to add a extra battery to my 1/2 ton ext cab but not sure where to mount it. Any advice is appreciated

The aux.battery on the NBS trucks is located in front of the firewall on the pass.side right underneath the fender to firewall brace.

You can purchase a battery tray from your GM dealer,part number#15705102 which lists for $24.82.

Worktruck · September 11, 2004

Thats right where the isolation module is for the plow. I suppose I could move it though. Thanks.

n8huntsman · October 15, 2004

How can I find out which alternator I have on mine? It's an 01 1500 HD. And I'm actually gonna go with a 600 watt inverter but probably wont be using all 600 watts, Maybe 500 max.

h8dviks · October 15, 2004

I too would say go with the red top for starting your truck and the yellow top for running all the goodies with. The yellow top will do a better job and last longer in this application. IMHO I wouldn't go with an inverter smaller than 600. Why not get the 800 or 1000 inverter and have room to grow. I would rather spend the little extra money up front and not have to replace it a little ways down the road if I got a new toy. Just my 2 cents worth.

dsrour · October 17, 2004

What other parts are needed other than tray. I'd like convert my yukon xl 8.1 to duals, mainly for plowing. Thanks

n8huntsman · October 18, 2004

Which yellow top should I get? I won't need a lot of cranking amps, so I can get the 500 amp battery, right??? There is a $50 price diff.

http://store.summitracing.com/default.asp?...t=optima+yellow

h8dviks · October 18, 2004

Go with the yellow top that best fits your budget. You will be using the red top for your cranking amps so the lower CCA yellow top should work ok. The main reason to go with the yellow is the deep cycle feature for the electronics.

n8huntsman · October 28, 2004

Thanks for all your help. I found a 1500 watt inverter at Costco for $85 so I went with that. I ordered the new D31 optima yellow top. It has the highest reserve capacity. I also got the battery tray from the dealer and a solid state battery isolator to prevent a dead starter battery. I also got the computer, touch screen monitor, xm radio for the computer with software to "tivo" it, gps navigation, a radio/tv tuner, new sound card to make it all sound good, dvd player, and wheels and tires -finally. Ill put some pics up on my site soon. As soon as I have some time its gonna get painted too.

99-2door · October 28, 2004

Can someone explain how to hook up the unit to make sure there is no main battery drain?

My dad just got a 97 K3500 with dual batteries and the stock set-up has no interupt. They are wired straight parallel.

sperry · October 28, 2004

A single Odyssey PC1200 will crank over a Duramax AND will deep cycle AND will accept FULL charge current. (Actually, most good AGM batteries will). They're just a bit pricey. I'd increase the cable size a bit though.

Also there's a PC1700 75AH

Or, install the PC2150 - 100 AH if you can fit it

Note that the PC1200 is only a 50 AH battery by capacity (About the same size as the Optima).

Odyssey Batteries - West coast

Odyssey Batteries - East Coast

n8huntsman · November 1, 2004

The site I read says the 1700 is only 65AH. It may be wrong. But either way, its more money than the Optima that I got which is 75AH. Too late anyways. Thanks for your help.. And to answer the question before; you'll need a battery isolator. Solid state is the best. Heres the link to the one that I got. http://www.campingworld.com/browse/skus/in...cfm?skunum=6688

Peter_C · November 2, 2004

I have one of the Costco 1000 watt inverters mounted under the back seat of my Burb also. Without a second battery it shut down everytime I went to start the truck. So I added a second battery in. It just so happens my 01 Burb already had a battery tray on the passenger side. I bought two red top Optimas which are AGM's from Costco also. Don't need a yellow top as the red will do just fine. What I did do differently though was to run a Stinger 200 amp constant on relay to isolate the batteries. Now I can jump myself and never have to think about flipping a switch or loss of power due to diodes. This is the way most of the high end stereo guys are doing it, and the relay is only $62.00 list price.

I have one of the Odyssey PC1700 metal jackets mounted in my Jeep and swear by them. AGM's are the way to go...but you need to be aware of charging requirements.

AGM=Absorbed glass mat

Optima calls it spiral cell technology, same thing different name.