NHRA Battery Rules

[ALMACK]

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]

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.

[FireSale]

For Stock, the 2016 rule book states you are limited to a max of two batteries weighing in at a total not to exceed 150 lbs. They must be the same size, type and weight. Brand isn't relevant. I have two 12 volt AGM batteries of the same class size in my Mustang that I built for GT/MA. One is Optima and the other is SuperStart. Both are heavy. One light and one standard is a no-go in Stock.

EDIT: Jeff, I read your first post, which said Stock and your last one which said Stock style Bracket (SSB/). You should be OK mixing battery sizes in ET/Pro or Sportsman, but email your tech before spending the money.

EDIT 2: In regards to charging, if they are wired in PARALLEL I don't think it will make a difference to the charger. It will see one big battery. I found putting two parallel connected batteries on a charger tripled the full charge time. AGM 12 volts on a charger with a AGM setting.

EDIT 3: I was wondering about the safety of using two different size batteries so I found this similar question on a boating forum:

Question: Due to space considerations I want to use two 105 amp hour and two 150 amp hour batteries as a house battery bank. Would this arrangement be detrimental to the smaller batteries?

Answer: My gut reaction is that mixing two sizes of batteries would be a bad idea. Having said that, I really can’t think of a technical reason that it would not work. Let’s see what our battery guru, Justin at LifeLine Battery says:

“It has previously been said that this is not a good idea; however, we have done some pretty extensive lab testing and we can find no differences in the batteries. Age is important but size is not. You can safely mix and match battery sizes in one bank.
Also, Sabre Yachts does this from the factory. This was one of the reasons we started testing this scenario. Sabre use a GPL-4DL and when they want to upgrade a battery bank they add a GPL-31T.”

Dale

[Coleydog]

Talk about taking an acid trip if the shaft brakes! Look out I see an explosion proof box in the future from the guys up top.

[DIV3CR]

I run my starter & ignition of the rear battery because the rear cut off
switch will stop the engine like I was told. The front battery runs the
water pump & fan. At RTE 66 points a NHRA tech guy said I have to
start my car with the front battery?????

[Jeff Stout]

Originally Posted by FireSale

For Stock, the 2016 rule book states you are limited to a max of two batteries weighing in at a total not to exceed 150 lbs. They must be the same size, type and weight. Brand isn't relevant. I have two 12 volt AGM batteries of the same class size in my Mustang that I built for GT/MA. One is Optima and the other is SuperStart. Both are heavy. One light and one standard is a no-go in Stock.

EDIT: Jeff, I read your first post, which said Stock and your last one which said Stock style Bracket (SSB/). You should be OK mixing battery sizes in ET/Pro or Sportsman, but email your tech before spending the money.

EDIT 2: In regards to charging, if they are wired in PARALLEL I don't think it will make a difference to the charger. It will see one big battery. I found putting two parallel connected batteries on a charger tripled the full charge time. AGM 12 volts on a charger with a AGM setting.

EDIT 3: I was wondering about the safety of using two different size batteries so I found this similar question on a boating forum:

Question: Due to space considerations I want to use two 105 amp hour and two 150 amp hour batteries as a house battery bank. Would this arrangement be detrimental to the smaller batteries?

Answer: My gut reaction is that mixing two sizes of batteries would be a bad idea. Having said that, I really can’t think of a technical reason that it would not work. Let’s see what our battery guru, Justin at LifeLine Battery says:

“It has previously been said that this is not a good idea; however, we have done some pretty extensive lab testing and we can find no differences in the batteries. Age is important but size is not. You can safely mix and match battery sizes in one bank.
Also, Sabre Yachts does this from the factory. This was one of the reasons we started testing this scenario. Sabre use a GPL-4DL and when they want to upgrade a battery bank they add a GPL-31T.”

Dale

Thank you for the info. I'm going to install 2 different sizes parallel and go for it. I thought 1 braille would work but it won't. It will start when engine is cold but not after its warmed up.

[Rich Biebel]

Originally Posted by Terry Cain

Well, since it was brought up I'll add something to the mix. 68 and up Corvettes have the original battery located behind the drivers seat inside the interior less than 12 inches from the tunnel where the driveshaft is rotating. Think about that.

Very bad deal there and I know first hand how bad.
I pulled an engine on a '69 Vette at home for a customer and we rebuilt the engine at the shop I worked at. An LT-1 350.

Reinstalled fresh engine and recall tugging on positive battery cable as it was very tight going on the starter solenoid.

Got engine running and all was ok after struggling with a few typical Corvette issues....

Started to drive it to work....a 10 mile ride....Heard some odd crackling noises and saw some smoke at the shifter console....realized something was burning up electrically under the console......pulled over and was able to push the console out of the way and stop the dead shorted battery cable that had been whacked repeatedly by the u-joint and had shorted out....console luckily was loose...

Car was dead in water.....parking brake did not work.....nosed it into a curb on a down hill street.....more to the story but that was plenty already...

I never had anything but bad things happen anytime I worked on a Corvette.....and I have a much worse story....!!!

[George Mirza]

The original reason for the second battery came about when Nhra stopped the practice of cooling the cars in the staging lanes with cold water. They allowed a second battery to run extra fans and water pump drives to make up for the cooling. But over time the use of the second battery became blurred and now is used as part of the electrical system. Problem is in a stocker you need a working alternator which makes the ability of the master cutoff switch to kill the car a complicated issue. This is one of those gray areas where every tech guy and division has their on take on it. The master switch on my car has never shut the car off, only the accesories hooked to it. I always started and ran my car with the front battery and alternator. The rear battery was used for cooling only and not tied into the charging system.

[SSJ343]

Here is what I did in ’67 Camaro Stocker: Installed main switch on roll bar horizontal pipe behind front seats. It was mounted behind passenger seat and operated via long ¼ inch diameter rod from rear of the car. I could turn it on and off from driver seat also. Equal length cables from both batteries to switch and relatively short cable from switch to starter etc.

[Run to Rund]

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.