[Tileman]

Wyldman This is in response to what I said in my email. Would you give me your view on aux batt on gm products. I always though the main batt ( start batt) charged first and the aux batt charged second. For this reason you would want to hook you plow to the start batt. Is this correct or not. This is on the factory set up from gm on a 2000 gmc.

Thanks

Tileman


PS Where is the spell check?

 

[wyldman]

Most dual battery setups are connected in parallel,or together.So the are one in the same.They charge together,and discharge together.It really doesn't matter where you make your connections at all.It may be easier on the second battery,as they only have one battery cable on each post,unlike two on the main battery,where the battery cables are joined.You can get battery bolt extensions for adding additional items.If your accessories run the batteries dead,then they will both be dead,and the vehicle will not start.Because the batteries are conected together,the voltage regulator just see them as one big battery,and they are charged together at the same rate.

If you have an isolated system,then the two batteries are isolated,and are connected separatly to different devices.Usually one for starting,and one for accessories.If the accessories draw the one battery dead,then the starting battery will not discharge,and can be used to start the vehicle.A battery isolator is used to prevent one battery from discharging the other,and to determine the different charging rates for each battery.It will usually charge the main,or starting battery first,then the aux battery.

The parallel setup is best for a plow truck,as you need the extra reserve capacity that two batteries provide.An isolated setup would not function well for this application.Your GMC should be a parallel setup,so your fine.

 

[campi]

aux battery

tileman, I think i went over this once with wyldman, i have 80 chev all re done i have 2 batts hooked up my plow is hooked up to start batt!! also have 140 amp alt, been running it this way now for 2 yrs no problems!! Campi !!!!!

 

[Tileman]

Thanks How would you know if you had the isloated system?


My truck cam with snowplow prep, and aux batt.


Tileman

 

[wyldman]

Just follow the battery cables.If you have one or two large cables between the two batteries,then they are in parallel.They should connect positive to positive,and negative to negative.It is also possible that just the two postives are tied together,and grounded individually.

If it's isolated,you will see an isolator somewhere (looks like a small stereo amplifier) connecting the two charge wires to each battery.There will be no physical connection between the two batteries.

Your GM will be in parallel

 

[Tileman]

O K now I under stand. Thanks

Tileman

 

[JohnnyU]

I added my second batter the old skool way.

I just ran a ground to the engine (same point as primary battery ground) then ran the pos cable across the fan shroud and hooked it onto the primary battery's pos terminal. That's how my dad and uncle always did it in the 70's and 80's. Mine has been fine for a year now. *knocks on wood*:grinz

 

[TJS]

This will also work. It isolates the battery without the high cost of a battey isolator. Follow the link. It was cheap to buy the parts.


http://www.tjsperformance.com/dualbattery.htm