NHRA Battery Rules

DIV3CR · 06-06-2016, 02:21 PM

On a stock car if you have a battery in the trunk and one under the
hood what does the front battery power and what does the battery
in the trunk power, buy NHRA rules.

Lew Silverman · 06-06-2016, 02:52 PM

I don't think the rules drill that far down - the only requirements are that both batteries be physically the same (no dummy battery up front!), the rear battery is mounted properly and that your battery shutoff kills the power to the whole vehicle. Other than that you're on your own, although most folks power the fuel pump/module with the rear battery through a heavy-duty relay.

B Aceves · 06-06-2016, 07:58 PM

Quote:

Originally Posted by DIV3CR

On a stock car if you have a battery in the trunk and one under the
hood what does the front battery power and what does the battery
in the trunk power, buy NHRA rules.

It does not matter . Most guys wire them in series so it doesn't matter what you have hooked to either battery they will draw the same other than the difference in length of wire and voltage drop because of that. My concern has always been the live wire going from front to back even with the master switch off .
Until NHRA realizes that it just isn't safe because of that among other reasons maybe they will finally let us move the other battery to the back .
Last time I brought that up though I received some death threats and powder laced letters in the mail lol..But hey we got roller rockers now so everyone is much safer now and all is good.

7423 · 06-06-2016, 09:47 PM

Quote:

Originally Posted by B Aceves

My concern has always been the live wire going from front to back even with the master switch off .
.

BINGO..............starter in the front, battery in the back, 12 foot of positive cable, not very safe. If it was such a good idea the OEM would have done it years ago. Run one battery in the factory "stock" location in your stocker. What a concept, something stock in a stocker.

426Fred · 06-06-2016, 10:32 PM

Forgive me if I am wrong but don't the big three (GM, Ford, and Chrysler) install batteries in the rear of a lot of their new vehicles now? Super Stockers have been running batteries in the rear only since the early 60's. If you pay attention to what you are doing and follow safe wiring practices too include the correct size positive and negative battery cables, you will be just as safe as only having one battery in the front.

ALMACK · 06-07-2016, 07:47 AM

Quote:

Originally Posted by 7423

BINGO..............starter in the front, battery in the back, 12 foot of positive cable, not very safe. If it was such a good idea the OEM would have done it years ago. Run one battery in the factory "stock" location in your stocker. What a concept, something stock in a stocker.

^^

I totally agree with Charlie.

I have never liked the idea of a big fat " hot all the time" cable running from rear to front.
Once you have one short on you, you'll understand....ask me how I know. lol

Obviously this will not work on a Stocker, but this is how I have wired all my bracket cars for years ( not any of my Stockers tho)

The rear main power switch kills the engine and all power to the car immediately, but never handles the starter current:

Jeff Stout · 06-07-2016, 10:51 AM

Besides the NHRA rule that states batteries must be the same size can I use 2 different size batteries? This is a stock style bracket car and I want to switch from 2 red tops to 1 red top and a braille. I like the 2 battery for the amperage but trying to reduce weight. With the 2 size batteries I can save 14 lbs but not sure if charging will treat both batteries equally or will the smaller one get over charged.

Run to Rund · 06-09-2016, 10:27 AM

Quote:

Originally Posted by 7423

BINGO..............starter in the front, battery in the back, 12 foot of positive cable, not very safe. If it was such a good idea the OEM would have done it years ago. Run one battery in the factory "stock" location in your stocker. What a concept, something stock in a stocker.

Oldsmobile ran a 16 foot cable to the battery in the trunk 50 years ago, but it ran inside the frame.

FireSale · 06-06-2016, 11:16 PM

Quote:

Originally Posted by B Aceves

It does not matter . Most guys wire them in series so it doesn't matter what you have hooked to either battery they will draw the same other than the difference in length of wire and voltage drop because of that. My concern has always been the live wire going from front to back even with the master switch off .
Until NHRA realizes that it just isn't safe because of that among other reasons maybe they will finally let us move the other battery to the back .
Last time I brought that up though I received some death threats and powder laced letters in the mail lol..But hey we got roller rockers now so everyone is much safer now and all is good.

Whenever the topic of dual batteries comes up, series and parallel get mixed up. Series is wired + to - and doubles the voltage. Parallel is wired + to + and doubles the amperage. Parallel makes two 12 volt batteries into one big strong 12 volt battery. Never wire 12 volts in series in a race car.

Dale

Coleydog · 06-06-2016, 11:37 PM

If you have an alternator why do you need two battery's? Sounds redundant.

06-06-2016, 02:21 PM	#1
DIV3CR Junior Member Join Date: Oct 2011 Location: WISCONSIN Posts: 50 Likes: 0 Liked 3 Times in 1 Post	NHRA Battery Rules On a stock car if you have a battery in the trunk and one under the hood what does the front battery power and what does the battery in the trunk power, buy NHRA rules.

06-06-2016, 02:52 PM	#2
Lew Silverman VIP Member Join Date: Mar 2010 Location: Newport News, VA Posts: 1,435 Likes: 371 Liked 129 Times in 59 Posts	Re: NHRA Battery Rules I don't think the rules drill that far down - the only requirements are that both batteries be physically the same (no dummy battery up front!), the rear battery is mounted properly and that your battery shutoff kills the power to the whole vehicle. Other than that you're on your own, although most folks power the fuel pump/module with the rear battery through a heavy-duty relay. __________________ Lew Silverman #2070 "The Wagon Master" N/SA

06-06-2016, 10:32 PM	#5
426Fred Junior Member Join Date: Aug 2010 Location: Sewell, New Jersey Posts: 74 Likes: 0 Liked 2 Times in 2 Posts	Re: NHRA Battery Rules Forgive me if I am wrong but don't the big three (GM, Ford, and Chrysler) install batteries in the rear of a lot of their new vehicles now? Super Stockers have been running batteries in the rear only since the early 60's. If you pay attention to what you are doing and follow safe wiring practices too include the correct size positive and negative battery cables, you will be just as safe as only having one battery in the front. __________________ Fred Palumbo 1025 STK

06-07-2016, 10:51 AM	#7
Jeff Stout VIP Member Join Date: Dec 2001 Location: phoenix Posts: 1,486 Likes: 66 Liked 704 Times in 281 Posts	Re: NHRA Battery Rules Besides the NHRA rule that states batteries must be the same size can I use 2 different size batteries? This is a stock style bracket car and I want to switch from 2 red tops to 1 red top and a braille. I like the 2 battery for the amperage but trying to reduce weight. With the 2 size batteries I can save 14 lbs but not sure if charging will treat both batteries equally or will the smaller one get over charged.

06-06-2016, 11:37 PM	#10
Coleydog Senior Member Join Date: Jul 2014 Posts: 569 Likes: 36 Liked 53 Times in 38 Posts	Re: NHRA Battery Rules If you have an alternator why do you need two battery's? Sounds redundant.