'71 T Coupe - Battery Choices/Configuration

[hages]

Hello,
Getting my dormant 911T back in running order. Is it still preferred to use a dual battery set-up? i heard some have opted to use only one. If so, where do you locate that one battery? What batteries are you using that are still readily available?

Thanks for your feedback!
Rod

[Chuck Miller]

More looks over here in 'Technical' hages ...

[Scott A]

I use dual battery.
The size is 36ah

You can easily spend $250 to $400 per battery.


I don’t do that, I spend less than $90 a battery, on Amazon, you can get a 36ah interstate battery. AGM.
You buy brass terminals that thread on the battery.
You lay the battery on its side, so it doesn’t touch any metal.

I attach a photo later, as it is equivalent to 1000 words.





I had to rethread so the automotive terminal could screw on.
But you can buy hollow terminals and put a socket head cap screw inside.
I put a wood 2x6 or 2x8 under the battery so I could use factory ‘hold down strap’.



These are hollow, I cut off the threads, drill a hole and use a separate bolt to screw it on.
I use the bolt on top to permanently attach a trickle charger.

[McOtto]

Hello,
Getting my dormant 911T back in running order. Is it still preferred to use a dual battery set-up? i heard some have opted to use only one. If so, where do you locate that one battery? What batteries are you using that are still readily available?

Thanks for your feedback!
Rod

These threads may be helpful. . .

https://www.early911sregistry.org/fo...dual-batteries

https://www.early911sregistry.org/fo...double-battery

http://forums.pelicanparts.com/porsc...tteries-2.html

http://forums.pelicanparts.com/porsc...tteries-2.html

And for what it’s worth, I recently purchased and installed two Sonnenschein A512/40A batteries. Not the least expensive option, but very pleased with performance, fitment, dual-battery originality and like the fact that the batteries are not vented. I keep them topped off with a Battery Tender® 6V/12V, 5 AMP Lead Acid & Lithium Selectable Battery Charger.

Regarding your question on where to install a single battery, my ‘72 previously had a single battery in the driver-side battery box, with the cable to the passenger-side battery box disconnected.

[62S-R-S]

Just a thought, that an uncramped area for a battery is a m-a-j-o-r benefit, and so the idea of having twin batteries in opposing close knit spots, is nightmarish imo.

12V that can be quickly disconnected, connected, checked for voltage, etc, becomes a pleasure to work on, maintain as well. Porsche did a nice job with the SC, having one pretty accessible. After that, the smugglers box is an alternative for racers and track cars, though ends up somewhat buried. If not directly on top (a favorite) perhaps half the battery could be situated downward yet with terminals a few inches above ?

[dogLeg]

My car came with a single battery in the smugglers box (rennline makes a mount for it). When i restored it i switched back to 2 batteries in the orig spots. Its good to have the weight up front in the corners. We put 2 Miata batteries in and they fit perfectly. they have been running strong for a 3-4 years now no issues at all. Would not go back to single.

[62S-R-S]

Not original, but note space [ around ] the battery.

Cables and hardware...bulletproof :

[hages]

Thank you all that responded. Super helpful!!

[RSTarga]

Not a fan of exposed positive terminals.
I went through many variations, and if you don't want to spend on the sonnencheins two Miatas are close, but will require spacers. At least the terminals are not as exposed.

[McOtto]

Not a fan of exposed positive terminals.
I went through many variations, and if you don't want to spend on the sonnencheins two Miatas are close, but will require spacers. At least the terminals are not as exposed.

Strongly agree with David’s recommendation. I used these readily available covers on the positive terminals (Part No. 999 611 104 00).