We run a red top for the ignition and a yellow top for everything else, no alternator.
Bill

2 Wal-mart battery's, no alternator, and no belt o flip off. Charge between rounds while I'm off bsn.

2 battery's and a 78 amp alt for me.

I loved the switch to two batteries .
No more fear that it wouldn't start after running the cooling fan in the staging lanes.

So far all the testing I`ve done , one yellow top and a 75 Amp West Coast Electric alt. We`ll see how this lasts up after some hot laps.
Chryco

Just one little Orbital battery and an East Coast Auto Electric alternator. Works for my turd.

1 optima YELLOW top... and a chevy alternator...

1 red top battery and a 100 amp alternator.

I threw in one of these 78 pound Odyssey beasts and had a 75 amp alternator rewound to put out 100 amps.

2 Red Tops and a 100amp alt. N2O and plenty of electronics include all working lights. Added the alternator last year and only charged the batteries a couple of times between rounds after I left the fans and pump run for an hour.

2 batteries and no alternator will look like this as far as battery voltage going down the track. Open attachement and view full screen. This is with Mallory 250 pump, MSD 7AL2, Mega 85 Delay box, tail(LED) and dash lights, CO2 rpm activated shifter control, RPM Datalogger, Electric water Pump drive, and Shogun Dial board (LED) running. So no problem with voltage as some would lead you to believe but I do have to charge between rounds which some may not want to deal with.

One thing most people don't know is that a fully charged battery has about 2.15 per cell [ 6 cells in a 12 volt ] when fully charged, If you have only a 12 volt reading your battery is 80 percent discharged.

That is great info 540duster. and an awsome graph. My car is not set up for an alt. as well & I have 2 batts. Where do the guys running an alt. mount it at? Esp those w/ motor plates??

I built a lower mount on my right elephant ear out of so aluminum channel . The adjuster / tensioner mounts to the frame .
Chryco

Thanks for all the information guys.
its nice to know what everyone is using and why.
Ron....

I run one with an alt, but I went dead on the line in the quarter finals because I broke a belt and didn't know it until the motor started to skip from low voltage. Having 2 batts would have saved me.

Hope this isn't a hijack or too dumb...but...all I've ever run is one red top and no alternator (charge between rounds)...how do you wire two batteries in?

Connect + to + & - to - 12 vdc with twice the amp hrs

2 batteries with an alternator because I don't want to take a chance of going dead in staging lanes.

I`ve been running two gel batts for years and what a difference it makes in easier starts and being able to run fan and elec water pump for cool downs not to mention starting.