Dragster Nut, are you asking about 18 volt, because that is what you are using to start your car now? You might want to call your data computer guys about 18 volts.
We use a 15 amp, 12 volt 1lb lithium battery in the car to power the trans-break and RacePak for 4 years now.
If you change to a remote battery pak, the cheapest would be two 12 volt car battery in your tow truck or golf cart. The remote battery pak we used before our current two Harley Davidson Lithium batteries is two Harley Oddessy batteries. One trick to consider is all the teams using a remote battery use a quick disconnect connector, I get mine from a fork lift dealer, but look, ask around other racers you race with to see what size/ color connector they are using. Talk to all of them about using the same connectors so if anyone is about to start, but have a dead battery, then another team can just plug in and get going.
Most JrFuel racers use A MSD 12 or 20 amp mag, ign box and two step. Again, they all use a 24 volt battery start system. The down side to lith batteries is the cost, the batteries I use and sell thru Hayden Wheels cost $260 each, but my crew is happy the new battery pak carrier, and cables weighs less than 10 lbs.
The reason the JF guys use the MSD mags is with high compression, high RPM, and allot of fuel flow, you get high combustion pressure, so the motor needs more juice. Now I understand Spud has had some success with his Mallory, hoped up points mag.
Feel free to call my cell anytime if you have any questions. 805-444-4489,
Jon Hansen , haydenent.com