6Volt Battery 77 or 84 Ah?

[Guido Kwikkers]

I have a 64 C Coupe with 6 Volt and an electric sunroof.
According to the Porsche PET the battery should be 77 Ah.

However several sites mention that 84Ah is the correct one.

What is correct? Please advice.

[James Davies]

Hi Guido, the pre-A and 356A workshop manuals say 84Ah for coupe and cab. I can't imagine they made it smaller for later cars, though perhaps people could double-check their later sources.

If I recall, the pre-A Speedster battery was the smaller 77Ah version, but there's contradictory information in the workshop manual on this. The pre-A parts book section on the Speedster shows a smaller battery (battery cover has the wood blocks to hold a smaller battery), but the electrical diagram shows 84Ah.

Very early Porsches from 1950-51 used the 77Ah battery, but I don't know when they switched to the 84Ah version. I suspect it was in early 1952, but that is just guess.

[Brad Ripley]

Currently available German hard rubber case batteries have slightly different Ah ratings. The original 84 Ah is now 77 Ah. The case has the same measurements. You can buy the Porsche factory one here http://www.nlaparts.com/store/porsche-c ... -3476.html or aftermarket here: https://www.wolfsburgwest.com/cart/Deta ... ?ID=ZVW112

For early Speedsters a 66 Ah battery was used, hence the wood blocks in the metal battery cover -- that battery is quite square shaped. See https://www.wolfsburgwest.com/cart/Deta ... ?ID=ZVW111

Note: the round circle in the side of these batteries is for the sticker like this one: http://www.nlaparts.com/store/varta-bat ... -3197.html

[Wil Mittelbach]

I have a 64 C Coupe with 6 Volt and an electric sunroof.
According to the Porsche PET the battery should be 77 Ah.
However several sites mention that 84Ah is the correct one.
What is correct? Please advice.

The "356C Driver's Manual" (of which re-prints are available if you don't have one) page 22 indicates a "6v 84 Amp hr battery". Current replacements are 77 Ah, as Brad indicated.

[Guido Kwikkers]

Porsche let the batteries produce by a German Company called 'Moll Batterien'. The sticker from the Porsche sourced 356 battery indicate this. However Moll has also the same model with 84 Ah available.

I don't know if they do deliveries to the US (I am based Germany/Netherlands) http://moll-batterie-shop.de/moll-oldtimer-batterien
But it could be interesting to check for other 356 members looking for original batteries.

[Edwin Ek]

With the great help of a fellow Registry member, we imported two of the proper Moll 84 a-h batteries from Germany. It is hard to understand why Porsche itself doesn't sell the proper Moll one.

I looked at Guido's link, and Moll has a 150 a-h 6 volt in the right shape! I wonder what that weighs.

[David Green]

Does a 1953 take a standard Group 1 battery (approx 6"x9"x6 3/4")?. Restoration Battery makes a period-looking case with AGM cells, 6.4v, and I don't know it will fit inside my original battery cover.
Thanks,
David

[Brad Ripley]

In my post above I was incorrect about the amp/hour ratings. Sorry, I was feed bad information about the current version of the Porsche-supplied battery. I do not understand why Porsche decided to source the smaller 77Ah battery for their classic program. The correct battery (from Moll) is the 84 Ah version; the original fiberboard cover should fit perfectly.

Edwin, please report back after you receive your batteries from Moll.

[James Davies]

Bosch also makes the correct batteries.

http://www.bosch-automotive-tradition.c ... easer.html

The physical dimensions for the 77Ah and 84Ah batteries are different (and standardized), so I suspect only the 84Ah battery can work for cars that originally came with that size, correct? This is certainly the case for the pre-A cars where the tin battery cover is sized to work with the exact size of the battery, holding it snugly in place.

The currently-produced Moll and Bosch 77Ah batteries are the same physical size. And the Moll and Bosch 84Ah batteries are the same size.

[Edwin Ek]

Brad, we bought our batteries in August of 2014. They were shipped dry of course, and came with cans of German battery acid. They have a yellow Moll logo in the front (back?) and look great. Neither of us has installed his battery yet: his old (incorrect) one hasn't died and my car is having an engine rebuild after 22 years of storage.

Hard to believe, but Moll doesn't have any US dealers. Joma parts in Belgium sells the correct one.

I looked into Bosch batteries at the time, and if memory serves they weren't making the right version for our cars. Looks like they are now.

I am looking for an original fiberboard battery cover, if anyone has one. I know there are nice reproductions.

[Guido Kwikkers]

I noticed that Bosch started selling their old batteries again 6v/77ah and 6v/84ah.
The 12volt version will be available later. Available through Bosch (Klassik) workshops in Germany and problably elsewhere.

http://www.bosch-automotive-tradition.c ... tterie.pdf

So I wonder: were 356 C orginally equiped with Moll or Bosch batteries?

[James Davies]

Cars were equipped with a variety of batteries depending on target market, I suspect. Just like tires.

In the Porsche workshop manuals, they show photos of Berga, Varta and Deta brands. This photo is from the 1954 Service manual, and remains unchanged through the A and B/C manuals. Bosch's own parts lists always list their batteries as replacement, not original equipment for Porsches. The 1964 Bosch Parts for Porsches lists the 6V 84Ah (model BA/6/84/1) battery as the one for the 356C.

[Matt Kreeve]

Apologies for the dead thread bump .. been searching a long while and no pcis come up beside this one which doesn't show the pieces in the car.
Does someone have pic of how the original battery was fitted showing the orientation of the wooden base in a T1A or T2 Speedster?

356 battery base and cover.jpeg (19.53 KiB) Viewed 3463 times

Is this correct? I ask as the way it sits seems less than perfect ie the overlap to the pressed ridge in the floor of battery box.

battery base fitted in 57 speedster.jpeg (113.62 KiB) Viewed 3460 times

[Matt Kreeve]

ok seems the drawing is correct and the board should be 'part number stickers' downwards and the board needs to be shaved a bit to fit.