dual battery setups

[440dart_72]

I am considering a dual battery setup for my car. The reason why is due to the fact that i have a hard time starting the car. The battery seems to drain very qucikly while starting it. The car is a 72 Dart, 440, Indy S/R's, 12.5:1 Compression, 630/650 cam. Stock starter. The stock starter will turn the motor fine. But i don't know if it uses all the juice to do it. Any suggestions?

[Bigfoot]

I would see if you could find somebody that has a 100A DC meter and put it in series with the starter and see how much it draws then you would know. As far as adding another battery, I did this to my 1/2 ton and added an isolator between the two battery's. When you start the engine it uses both battery's and when it is running it charges both but are isolated from each other. If one battery craps out on you, you still have the other one to get you going. It took a couple of hours to put in another battery holder plate and do the wiring but it is worth it. The 360 cranks over even at -40 deg with no problems and the piece of mind is great also because I find myself in the bush in the fall and I don't have to worry if the truck will start. If you leave your lights on by accident just the one battery will be dead but the other one will get you going. I am thinking of adding this to my car and putting the extra battery in the trunk, it would save a lot of hastles, esp when the wife forgets to turn off the lights and I have to go and boost her again.

[amxauto-x]

What size battery do you Have? What are the cold cranking specs?

[92whitedak]

990 cca should really be fine for turning over your engine, if the stock starter is doing its job. Otherwise, you might want to check and see if there is a drain somewhere in the electrical system. My Dakota had broken the switch in the glovebox that turned off the little light in there so it stayed on all night. I would wake in the morning and the truck would take a couple seconds to start up. Does it start up easier after you drive it for a while and allow the alt. to charge the battery?

[440dart_72]

My current battery is a 1000cca. But it doesn't seem to do the job. I have a BG 280, a stepdpwn box, and a Crane Hi 6 Box. I don't know if these will factor anything

[6 packin]

I was told that the newer starters like out of a 96 Ram truck is lighter and has more cranking power. Like a factory mini starter. Also make sure you hook the battery up were you keep the volts the same and increase the amps. Positve to negitave (series)

[skankweirdall]

Originally posted by 6 packin
Also make sure you hook the battery up were you keep the volts the same and increase the amps. Positve to negitave (series)

If you hook it up like that you'll get 24 volts! You need to hook it up in parallel, positive to positive, negatives to ground. My race car is done this way, no isolator or anything, although that is a good idea for a street car.

Is this a race only or street/strip car? If it's race only do you run an alternator and what amperage?

[6 packin]

Oops, gottem backwards didnt I.

[skankweirdall]

Well, if you hook them up that way it will sure spin that motor over!

[amxauto-x]

Yup it will! But the starter may not last all that long.

[23T]

Originally posted by 6 packin
Oops, gottem backwards didnt I.

But 24 volts shure would make that starter whirl for a while

[jelsr]

When you say hard to start there are a lot of things come to mind. Weak ign., float high (light flooding), cold plugs, timing, etc. When you say stock starter, there are 2. The longer one is more powerful, and the mini's are more so. Most "built" engines like yours should start almost instantly, good comp, good fuel, good ign. You can "cheat" a little with another battery wired in series and a couple of solenoids so you only have 24V when cranking and 12V the rest of the time. Will shorten starter life if you have to crank it for long periods. We set demo derby cars up this way so they will still start after running for long periods with no coolant. Can you spell ABUSE?

[92whitedak]

e-b-u-c-e

[jelsr]

LOL! Nice shot 92whitedak, proud of ya!

[92whitedak]

Mom says some day she going to enter me in the county spelling bee. Dad says he won't let me make a fool of him though

[23T]

Originally posted by 92whitedak
Mom says some day she going to enter me in the county spelling bee. Dad says he won't let me make a fool of him though

I know the felling my dad walked me to school every day, I was in the 3rd grade and he was in the 5th

[92whitedak]

AHAHAH. Good one.

[jelsr]

You guys are too much. I didn't go to any spelling bees, but I learned how to spell procrastinator cause I wanted to be one when I grew up. I never got around to it though.

[1972roadrunner]

Originally posted by jelsr
You guys are too much. I didn't go to any spelling bees, but I learned how to spell procrastinator cause I wanted to be one when I grew up. I never got around to it though.

really, moms keeps telling me i AM one...and i'm only 17! LOL. i'd rather play America's Army: Operations with others online than to fool with "The Great Gatsby" shit... WTF is up with that anyhow? reading that aweful waste of tree's isn't going to help me in life! OY

[92whitedak]

The Great Gatsby is a severe piece of americana literature that you should read just to be able to understand other things. Read it or I'm telling!

[1972roadrunner]

IT'S BOOORING!!! sorry, but i'd rather go to wyotech after (if ) i graduate, and i'd much rather be in the garage than read that waste of trees...sorry...if you wanna read it, read it...heh, i'm gonna use it as a fireplace starter...

[dusterrcr]

I have 2 batt,s and no alt in both my race cars.I have had situations where 1 batt will go bad (internal short or something) and it will kill the other one!--It happened earlier this season one batt crapped out and it killed a almost new Champion 900cca.Of course Sams club happily swapped it out,but it did cause that race car to stay home that day.----Would one of those isolators prevent this from happening? and would i still be pulling from both batt while cranking?

[92whitedak]

Yes, an isolator block would prevent that from happening. Because your batteries were actually "one" battery because they were attatched (in line or parallel makes no difference), once one dies, the other is going to start to get drained. An isolator block is nothing more than a couple of electrical diodes that only allow electricity to flow in one direction. In most cases it has three prongs. One in from the alternator and two out to each of the positive battery terminals. In this fashion, if one battery dies and starts looking for power throughout the system, the diode in the isolator block cuts it off and says "No way! You aren't getting power from that other good battery. Its your fault your drained. Have a nice day" They are relatively inexpensive and will usually last a good while.