One or two batteries for Stock Elim.
 

In the planning stage for a new car and was wondering about battery choices. Since we have to run an alternator, would like pros and cons of the following systems.Which one do you have and why?Thank you for your input.

1. Conventional one 12 volt up front w/ working alternator. Most popular.
2. One 16 volt up front w/ appropiate alternator. Don't know anyone using this personally.
3.Two 12 volts wired in series. Alternator hooked to both. Very popular.
4. Two 12 volts. One for starting and ignition hooked to alternator and the other to power everything else.
5.Another that I might not have considered. But not the one with a fake battery up front and one in trunk hooked to alternator. Don't want to go that route . Although a good way to shed 32+ front end pounds

Re: One or two batteries for Stock Elim.
 

Danny, I use option #2, but 2 or 3 will do just fine. What kind of car are you getting ready ?
Good Luck !

Re: One or two batteries for Stock Elim.
 

I hope this subject gets many responses as I am REALLY curious as to which route to take. I do, though, understand that car type/combo will dictate the number of batteries and the 12 volt versus 16 volt issue.

Re: One or two batteries for Stock Elim.
 

Kenny:
I'm leaving tomorrow for Charlotte,N.C. to pick up a 1976 Firebird purchased off E-Bay. Won't be out this season because I'm starting with a street car. I know it's a lot cheaper to buy a completed car but I enjoy building them . This may be my last racecar so I really want to do it right. Thanks for asking. I am leaning towards the 16 volt system right now. One of my Super Stock customers, who is really fast, said he would never go back to a 12 volt system and he only runs one 16 volt battery and no alternator. But I'm open to suggestions. Nothing is set in stone at this stage of the game except the color on the car which doesn't need re-painting. Danny

Re: One or two batteries for Stock Elim.
 

It is my understanding that the Voltage of the battery(12 VS 16) wasnt the real issue it was the Amperage available to run it all. I had been told the Voltage of a 12 volt battery drops below the best voltage to run strong ignition systems if you power a water pump, fuel pump and Fan from the battery.
Alternator takes power to turn.
Two 16 volts in series will run it all with strength to Start, Run and cool without dropping below the voltage to power the ignition and fire the wide gap plugs.
If you Must run the Alternator use the 2 12volts as if they are well charged it will reduce the power draw on the alternator and therefore the HP loss turning it.

Run Parallel not series

Re: One or two batteries for Stock Elim.
 

if you run a MSD box and the voltage gets below 10.5 volts YOU MIGHT GET high speed misses---- the more the battery is charged the better off you are--Comp 387

Re: One or two batteries for Stock Elim.
 

What about the black boxes that keep the voltage at a constant 16V even if the battery
voltage drops below 10V. We have one in our bracket car and it seems to work good, I can't remember who made it though. But here is one like on this web site.

techwest@techwestracing.com,

Re: One or two batteries for Stock Elim.
 

I just want to clarifly some info in your discussion....there is two posts for putting two batteries in series...do not do this as it will DOUBLE your total battery output that the vehicle "sees"...series is when you wire two batteries positive to negative with each other...in this scenario 2-12 volt batteries become one 24 volt battery, 2-16 volt becomes one 32 volt battery etc.....I am sure it was meant to wire them in PARALLEL, which is positive to positve, negative to negative, in this manner your voltage remains either 12 volt or 16 volt but it also gives you the advantage that you now have the current available to start and run high compression and high powered ignition system with no problems because you get the current as a total of BOTH batteries at once...also in stock if they decide to test your "dual" batteries, they both better be able to start the car seperately or they will be considered illegal ballast.....

D L RAMBO

Re: One or two batteries for Stock Elim.
 

On that, if the car came with a trunk mounted battery I have to from what I understand run that in the "Stock Location" ....where can I put the other one ? (yes I know it says in the trunk) is there any limit to where in the trunk I can mount it without them (tech) twitching.

Any problem say with mouting it right over my axle line offset for the best r/l weight dist ?

Re: One or two batteries for Stock Elim.
 

Over the Axle is as good as any in my opinion.... left or right depends on what your 4 wheel scales tell you... See you in Feb.:):) PS Both Bats supposed to be same type and weight

Re: One or two batteries for Stock Elim.
 

The funny part is I dont want to put another one in (even though I need to) Just because it looks so damm perty in there the way it is....

I spent probably 4 days alone on the trunk in paint and mounting and detailing, cutting firewall, ald this that and the other, now I gotta add something thall make all that work look like ****

I think it looks perty damm good.....Now Ive got to muck up the visual for another battery.

BUT its the right and legal way to do it so......but dosent have to make me happy.

Pomonas gonna be close, at a minimum well have only 1 day testing on the car......that dosent thrill me. But it is what it is....Im calling in some help from other sports (motorsports) to chip in and finish the build, Im calling in my favor chips which I never do, but need to. My dad and son both being in the hospital at the same time in the last 2 weeks hasnt helped my timing, but it was what it was and the priority was them, my son just got out yesterday, so its damm the torpedos and full speed ahead.

http://farm3.static.flickr.com/2458/...dd5ff3af30.jpg
http://farm3.static.flickr.com/2798/...5bab06f31e.jpg
http://farm3.static.flickr.com/2770/...d13845a7e4.jpg

Re: One or two batteries for Stock Elim.
 

Why do you need two.......nitrous bottle warmer? Unless you are going to run SS without the altenator. Put it in the weight box if need be. I don't think you will be needing to add weight to make class unless your driver is a 98 lb championship horse jockey in addition to being a driver of note.

Whats you car going to weigh race ready?

Eric

QUOTE=drooze;163190]The funny part is I dont want to put another one in (even though I need to) Just because it looks so damm perty in there the way it is....

I spent probably 4 days alone on the trunk in paint and mounting and detailing, cutting firewall, ald this that and the other, now I gotta add something thall make all that work look like ****

I think it looks perty damm good.....Now Ive got to muck up the visual for another battery.

BUT its the right and legal way to do it so......but dosent have to make me happy.

Pomonas gonna be close, at a minimum well have only 1 day testing on the car......that dosent thrill me. But it is what it is....Im calling in some help from other sports (motorsports) to chip in and finish the build, Im calling in my favor chips which I never do, but need to. My dad and son both being in the hospital at the same time in the last 2 weeks hasnt helped my timing, but it was what it was and the priority was them, my son just got out yesterday, so its damm the torpedos and full speed ahead.

http://farm3.static.flickr.com/2458/...dd5ff3af30.jpg
http://farm3.static.flickr.com/2798/...5bab06f31e.jpg
http://farm3.static.flickr.com/2770/...d13845a7e4.jpg[/QUOTE]

Re: One or two batteries for Stock Elim.
 

Beats the hell outta me....I know it WILL be one of the lightest DP cars (at this point), but by how much ? Ive got another 100+ I can pull legal long term, but thats HARD work and its having some items made I cant get done before Pomona. Steering col alone weighs over 30lbs for example....

Looks like noone has got a set whos in town I know , otherwise Id know next Mon or Tue when shes all back together. Ive just got to go buy some, but I dont know what summit has in stock, that was on todays list to check. (theyre about 10 min down the road) But on my other thread noone has suggested any so Ill just "wing it" and buy something thats overkill as usual.

The voltage for the electronics packages scare me, they like constant voltage. AND We are running COP so theres a hell of a lot more draw there than a single coil system. AND On top of that all electronic controls on the Injectors, ECU, Tranny, water pump, fans....just a lot of juice. And I DONT want it pulling from the alternator any more than it ihas to. So the only way I see is an extra batt. Im running enough of an underdrive on the Alt, it will be legal but not much more.

Hate to have an electronic hiccup because of low juice....then I kick my own *** for not doing it, or expecting it.

I NEED to make plans for it and be able and ready to do it at a minutes notice, but it wont go in until Im certain its needed, but I need to plan and arrange for it now. Ill know for sure in Dyno and track around the 23-30th

Re: One or two batteries for Stock Elim.
 

drooze.....you don't need a second battery just the right one for your application.....most stockers add it for the ballast not the extra capacity....if you take into consideration that a modern street car has a MUCH higher electrical demand than your race car, after all they have to be able to power everything in the car at once including A/C, interior blower fan, power windows,rear defoggers, high powered stereos and they are doing it with one battery.....yes the alternator in newer vehicles have a higher output, but they also rely on the battery reserve to start the vehicle after setting for one, two or longer number of days.....you will probably be throwing a charger on it between rounds and leaving it on a maintenance charger when not at the track....for your app, I would use a Braille battery 12v....they have one with 850 CCA @ 0 degrees (over 1100 CCA at 32 degrees)...it weighs 41 lbs. giving you a good compromise between power, weight and size....

Alternators take on average 1hp per every 25 amps of output that they are required to provide so as long as the battery (batteries) are at full charge the alternator will not go to full output, what hurts is when you have dual batteries and the alternator has to provide enough output to keep 2 batteries up instead of just one also if one starts to create a heavy current draw you have to figure out which one it is, you can end up with a performance issue that becomes difficult to diagnose and could be as simple as a battery that "pulls" more current to charge than the other even though they are the same....

To create a "rule of thumb" calculate your total current draw and size your alternator to provide just enough output to cover it, this way with fully charged battery (batteries) to provide the starting power once the car is running you will actually be running on the alternator so available power is a non issue with you race cars electrical needs....

The fuel pump voltage boosters are really only for cars with no alternator to keep the voltage constant at the pump while the voltage is being drained by the rest of the electrical items in the car.....alternators usually output between 13.5 to 14.5 volts constant during operation so the pumps output is usually fine....


D L RAMBO....

PS.....twrs2006.....for a "legal" stocker items #1 and #2 are good

#3 has to be PARALLEL or you end up with (again) 24volts which will cook most of your 12 volt accessories, also in parallel the alternator only has to be connected to ONE battery positive since both are connected together at the positive posts....

#4 and #5 aren't LEGAL in stock.....

Re: One or two batteries for Stock Elim.
 

Check, and thanks for the advice.

The second battery was going to be isolated for accesory items, (Light and Tailight, Fan, Windows, YES the DP Actually has Power Windows, lexan but power....and POSSIBLY the Fuel pump since all the other items are pretty isolated.)

The "Accesory" items were going to run off the second battery but the input/and draw from the alternator will be isolated as I will run an inline switch to handle it aside from the elctronics package. So Im not charging the accesory battery when I dont want to.

I asked the old man to go grab me an underdrive pulley for the alternator, I thought he brought back a damm balancer...lol....but I can get a smaller pulley, the alternator is one of the 50amp mini denso's so......

And the ballast was a consideration as well depending on what the car scales out at.....My other buddy who is a circle jerk is back in town he stopped by the shop this morning, and theyve got 3 cars going south for some roundy round but hes gonna bring his scales over this week later so Ill have a better idea.

The battery is a marine deep well unit I have , high amp (950 @ 32f I think, if my memory is right) and not so heavy (odd for a marine battery but true) so ....

Re: One or two batteries for Stock Elim.
 

drooze.....just remember that the secondary battery still has to be able to START the car as well as the primary battery (NHRA regs)....and as a side note... I personally won't use "deep cycle" marine type batteries anymore because they do not like to provide FULL cranking power on a start up...they are designed to allow as much power as possible while going to a full discharge of voltage.....I burned up 2 optima yellow tops before I found this out and now will avoid the deep cycle batteries for that reason....

D L Rambo....

Re: One or two batteries for Stock Elim.
 

Check....

Im sure the other would start the car even after 5 or 10 passes, since its only going to be running fans, water pump and some electronics....IF I need it.

Good to know on the deep cycles, I bought it for that reason, not the cranking amps, but if I end up with issues Ill know where to look.

Thanks for the note.

But very good to know....I was going to get one of those 400 cell lithium jobs till I saw the price ....Ive got some other ideas on that front later, heck a battery is easy enough to swap out....and cheap....Im always about 6 batteries short around here anyway the one thats in there was priamarily for testing (hence the deep cycle, wiring, load testing etc)....well see how it does from Dyno-Track.

A change may be in order though.

Thanks again

Cheers

Chris

Re: One or two batteries for Stock Elim.
 

Thanks to everyone for your replys. Drove the firebird back 600+miles with no problems. Hope it's that reliable on the track. Danny

Re: One or two batteries for Stock Elim.
 

Danny,


You don't need two Batteries as someone said, Run one good battery and keep it charged all the Time ....Stick with a good 12V battery , unless you are going to put a stick in that firebird ....... Send me some pictures ..