dual batteries

[superbee79]

gonna run dual batteries in the dart. not running long enough for alternator to charge battery and it's having a hard time keeping up with all the electrical stuff (gauges, pusher fan, electric fuel, pump and water pump. if i run them paralell they will still only put out 12v but have a longer run time. making charging between runs more effective. any thoughts.

 

[bOb shingler]

put 2 high amp marine trolling batteries in your hotrod. the ampacity stays up for an incrediable amount of time before it drops off. i've went 2 weeks and 2 races without charging them several times and all was good, of course i didn't mean to do it, just forgot. when you charge them you use a 1 or 2 amps charger.

 

[yellowdartdave]

Yep, 2 yellow topped Optimas should do the trick. $$$$

 

[67Dart273]

gonna run dual batteries ....................... making charging between runs more effective..

Just remember that the more battery you have, the longer /more amps it takes to charge between runs. Might have to buy a bigger charger/ generator.

You run with/ without an alternator? Remember your IGN system is meant to run on 14V, not 12. That's approaching a 20% difference in voltage.

 

[superbee79]

how is it a 20% difference in voltage two 12v batteries run parellel still are 12v i am missing the difference. still running the alternator but car isn't running long enough to charge battery by its self second battery is only for extra electrical accesories (fuel pump,water pump, pusher fan, fan inside car to keep me cool.)

 

[IfItsGotWheels]

I'm assuming you have a trunk mounted battery. When I was racing in the 80's I had the same issue. Instead of using a second battery, I bought a size 4DLT bus battery & installed it in the spare tire compartment, where it fit almost like it was meant to go there.

Where the best Exide orbital Marine deep cycle has a reserve capacity of 100 minutes @ 25A & weighs 41lbs, the 4DLT has a reserve capacityof 250 minutes @ 25A & weighs 87lbs. Plus it makes nice ballast for hard launches.

Pricewise 1 4DLT = 1 Exide Orbital.

Ther are even bigger batteries but weight quickly becomes an issue.

BTW I never succeeded in running that big battery down.

 

[67Dart273]

how is it a 20% difference in voltage two 12v batteries run parellel still are 12v i am missing the difference. still running the alternator but car isn't running long enough to charge battery by its self second battery is only for extra electrical accesories (fuel pump,water pump, pusher fan, fan inside car to keep me cool.)

What I meant was it sounded as if you were racing WITH NO alternator. This means that the ignition would be running off the lower battery voltage, not the higher 14V "running" voltage.

Since you are running an alternator, 't doesn't apply.

 

[superbee79]

I wasn't running the alternator at first, but all the accesories want some power. for the car to stay running and run all the accesories i had to put it back on.