i just put in a new battery, and may still have a small drain and am trying to gauge how long my car can sit before it won't start...

im pretty sure im losing ~ .1 volts a day as last night it was around 12.52 and right now 20 hrs later its at 12.44

so how much does it actually take to start the car?

with the old (most likely bad, although it was only 2.5 years old but i got it replaced under warrenty) the car would not start if it sat for more than about 48 hrs, and if you tuned on the accessories for more than 15-20 mins it also wouldnt start. i didnt think to put a volt meter on it while it wouldnt start, so thats why i dont have that reading

 

It normally takes around 200~250 AMPs to start a vehicle... Volts???? Not sure.....

 

Yeah thinking it's the AMPs that turn over the car. When my friends battery went bad and only clicked rapidly trying to start his 2K I put a digital meter on it and it was 10.2 if I remember correctly. A load test condemned it.

 

i tried checking for amps and ended up seeing sparks and my cables were warm, im sure i was doing something wrong, its been years since i took an electronics class.... do i need to disconnect the ground before checking for amps?

 

Unless you have an amp clamp you need to disconnect the wire and put the multimeter inline with the wire to determine amps.

 

No way you are going to do the meter inline, though, when starting the car. The leads will fry or your meter will (or both).

 

On computer controlled cars, you need proper voltage for more than just cranking the starter. Many of the pc modules require precise voltages. That being said, on an LT1 you're usually ok until you get down to around 9 to 10 volts, barring you have no other problems. You can produce the 200 to 250 amps. required to crank the starter at ANY voltage if the battery has enough capacity. You can often crank the starter on 8 or 9 volts, but that's not enough to run the computer.
In the 50's and early 60's cars ran on 6V systems.

 

Most true as most multimeters are only rated up to 10 amps, and as said above, the starter uses upwards of 100 amps.

 

like what was previously said volts have nothing to do with how well your battery works. its how many amps it can apply. even a battery that is pure crap that might only have about 60 cranking amps could still read 12.6 volts but as soon as you hit that starter nothing much is gonna happen