1971 911 Dual Batteries

[CheckBookChuck]

I am slowly converting my hot rod 1971 911 back to it’s original condition and am considering going back to dual batteries. I see that the Interstate 911U batteries are NLA. What are my choices now-a-days?

[dpetterson]

I have the Sonnenschein A512/40 A from Lauderdale Battery. Not cheap but worth it - https://www.early911sregistry.org/fo...-Battery-Bling

[Rick Cabell]

I second Lauderdale battery.

[NickP]

The Sonnenchein’s from Lauderdale are also my choice.

[Rick Cabell]

2 just came through the door

[Perry911]

I have used Sonnenchein’s from Lauderdale in my 1972 911T and yes they fit perfectly but the did not last as long as I would have liked. And I disconnect my batteries immediately when I am not using the car. I replaced them with the Marathon Mazda Miata batteries and although smaller I have found them to perform much better and for much longer time frames. I have wood spacers that sit behind them for a perfect fit.
I currently run the marathon's in both my 69 and 72.
Someone has to go against the above grain for a possible alternative.
https://www.batterymart.com/p-12v-ma...hoCmH0QAvD_BwE

[jim amato]

Perry, How long did they last?

[Perry911]

Perry, How long did they last?

I'm embarrassed to say one set is going on 9 years. They still hold strong. I should change them for age. I will buy another set without second thoughts.

[lopena]

I’m also running Marathon Miata batteries with good results. I back-dated them before installing:

[Orange71S]

I bought a set from Napa a few years ago. I don't know the part number, but they are affordable, fit well and have the required recessed posts.
Jay