Restoration Blog:

Which battery do you use in your 912/ 912E?  Has anyone found new "22NC" batteries like the original?  Do you use a size 45R or 51?   Have you used a sealed battery in your car so you don't have to deal with corrosion?

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From: John Lacey; ; I just replaced the original OEM battery two years ago, with an "Optima" battery.   Based on the cost, it must be filled with coelacanth teeth or gnat ears or something.  Works fine.  It will turn the engine weekly in mid-winter when it is very cold.  There have been occasions, where I haven't started it for a month, when I have run it all the way down, though. I put it on trickle a day before the rite of Spring, in anticipation of taking it out for the first time.  It fits in the battery box area, but just barely.  I have an extra rubber strap holding it steady. John L.

From: Randy Cohen;  ; The Optima battery is amazing!   It didn't fit in the stock location so I made a mount just outside the box.   The battery always has juice, and there is NO corrosion on the connections.   My generator belt is almost always loose, but never have to worry about the battery.  My 912 has no rust up front and with the optima I know it will stay that way!  Randy Cohen, 69 Targa

From: Robert Burn;  ; For the last 20+ years I have used Sears Die Hard batteries.  The last one that I bought was a model number 43224 in 1991 and it still works just fine.  I have heard from a number of sources that the quality of "Die Easys" has gone down the tubes in recent years.  I guess that when the current battery bellies up I will have a decision to make; that means watching the other replies to this Q.

From: Gregg Dunphy;  ; I put a red Optima battery in my 912E right after I replaced the front suspension pan. The pan was in tough shape when I bought the car in '91 and I babied it for quite awhile. If your pan is in good shape, do yourself and your 912 a favor and keep it that way by dropping in an Optima (non-acid-sweating, non-acid-spilling) battery at your earliest opportunity, treating the battery area to neutralize any acid residue there and repainting things as needed. An ounce ($120.00)of prevention could save you a $2,000.00 repair bill. Additional advantages of the Optima others have mentioned are: its quick recharge time, life expectancy and cold-cranking power. I'll never use anything else in any of my vehicles again. Gregg

From: Chris Smith;  ; Hi Rick, This is great timing since I've just finished removing my battery, de-rusting the battery area, cleaning out the adjoining areas, hosing down my new carpet after doing the baking soda treatment and repainting for the last time! I just bought an Optima 800ah(red) sealed racing battery for my 912E. The old mounting system was never engineered well so it didn't break my heart to do something different anyway. The old system capacitated the original battery ok but that battery was down on power and messy. The only rust on my car was the battery area(just like my 914 2.0). I paid $120 bucks for the Optima at a local shop here in the S.F. Bay area. Considering the fact that the Optima's last longer, charge quicker, don't sweat ,don't spill(therefore don't rust anything) and supply more current to my MSD that I just put in, it's a bargain at any price. Since the Optima mounts in any orientation I chose what fit  best which happened to be the upright position. I bought a plastic covered metal battery tray from a local parts store and bolted it to the original battery deck. The new battery mount kit plus all the hardware cost about 10 or 15 bucks to do it right. At the same time I re-checked the cleaned up the ground straps. Now everything works better from startup to lights. I strongly recommend this upgrade. It might seem expensive for "just" a battery upgrade but you'll never have to worry about all of the typical battery, rust, or power woes again. More power auch auch auch......
-- Chris Smith     

From: Anthony ten Kortenaar;  ; Re "912 Battery" Rick, I have a regular battery in my 912. The boxof the battery overlaps the battery box but is resting on a piece of wood  and is strapped down. It works wonderfully and I received no problems on the track last summer. Regards, Tony ten Kortenaar 

From: Peter Baldauf ;  ; I use an Duralast/Die Hard special group 45R (reverse).  They were nice enough to make the 'R' so the poles are on the correct sides both left/right a nd front/back.  Nice and compact.  I also use a quick disconnect, this helps prevent drain dramatically.  If your battery is leaking, replace it and treat the exposed areas to a health dose of baking soda and water paste, messy but effective.  Battery acid will eat your tray and suspension pan up faster than Godzilla on ***** *****.
Brgds, Peter Baldauf

New! 912 Registry Members can share technical information, add technical information, and access quality, up to date technical information on our 912 Wiki.