Battery Terminal Bolts

I installed the leads for a battery tender onto my car's battery terminals. The terminal clamp bolts/nuts were VERY difficult to unscrew for attaching the leads. I believed that they were cinched tight and then the threads were peened or some loctite was used. Regardless, they were so difficult to remove, it felt cross-threaded. On reassembly, one went one - still a little tough. But the other had damaged threads. I replaced the bolt & nut with a similar sized unit from a local auto parts store - but ti wasn't a battery terminal bolt, as the Cayman uses a smaller bolt. I wanted to replace those with the original factory ones (color me a purist). Anyway, they can't be ordered. They aren't in the parts book. You have to buy an entire friggin cable!! (I'm not that much of a purist). As it turns out, batteries in newer Porsches usually start failing in about two years, according to the Porsche parts dept. At that time, they will have a first hand look at what I discovered.

and I thought it was just me that screwed up... I had the same problem too putting on my CTEK. The positive terminal bolt wasn’t easy to take off and was impossible to put back on. The original square head bolt is supposed to be kept from turning by being against the clamp. When it was going on so hard, I thought I crossed threaded it somehow but it started okay and was halfway there. Then the head started to dig into the soft metal of the clamp to where it was turning free. Then I couldn’t get it tightened and couldn’t get it off. I had to saw through the bolt. Because of the battery top configuration and the shape of the clamp there wasn’t enough room to tighten everything so I got a socket head bolt...it uses an Allen wrench to hold/turn it. I had to use a wrench with the shortest leg possible to tighten it up. There are some holes in the top of the battery and the allen wrench gets pushed into one of them to keep it handy. I don't know about yours, but my instructions specified to use a ground instead of both terminals

tach miami, I didn't really read the installation instructions. I just matched colors The reason that they suggest placing the ground lead to a grounded location, other than the negative battery post, is that in a low state of charge a spark at the terminal (when connecting) could ignite the explosive gases that are present in the battery in that state. If you have ever seen a lead-acid battery go bang, it's not a pleasant experience, in the least. But since my battery was fully charged when connecting, it wasn't a safety concern. Maybe Porsche will have a recall on battery bolts!! LOL

Wonder if it like everything else Porsche and you need to buy the special expensive tool to remove the bolts? I've have mine connected to the lighter socket.

This is a very interesting topic since many people will use a battery tender on their cars. I just received mine from Boothe and am planning to connect it tomorrow. Not sure if I am going use the battery terminal mounts as yet, but with all the hard bolts, I will definitely take the knowledge to be careful with the threads if I do.

The battery tender I use comes with several interchangeable endings, including one for the cigarette lighter, which seems a satisfactory solution. If your tender does not, you can easily splice a lighter plug fitting to one of your unused leads and obviate the need for working with the battery . Note that there are special battery terminal removers (something like a gear puller ) available, and often necessary owing to corrosion, etc. Marty

I would not use one that didn't plug into the cig lighter, period. Russ

Same here.

Marty, The problem isn't with removing the battery terminals. It is merely loosening the bolts themselves. Just a simple six-point 10mm socket on the end of a Snap-on ratchet should be an easy enough task. But the nuts are gorilla tight. Or, maybe the nuts are Finish metric and the bolts are German metric ... whatever. The lighter splice is a good idea, but I prefer not having the window down to accommodate the charger.

You can leave the window up. There is enough room between the A pillar and the door to accommodate the battery tender wire. It doesn't even crimp it.

That's cool. As it is now, I run the cord under the hood.

Sorry but I must have missed something. Are you using the lighter socket to charge the battery - Battery Tender plugged into a wall outlet in garage and other end plugged into Cig Lighter ? I thought you plugged the Battery Tender into a wall outlet and then attached the other end to your battery ? This is how I do it on my motorcycle. Thank you for your help. :beer:

MDR, yes that is exactly what I do (I have the Porsche battery tender on the Cayman and one like Boothe sells on a truck).

battery tender jr and lighter adapter I bought the battery tender jr for less than $30 delivered and a $5 male lighter adapter. Cut the battery connection terminals off the supplied battery terminal connector that comes with the bt jr. Splice those wires to the adapter and plug into the power outlet plug in the center console glove box and start charging without messing around with the battery terminal connections. The only difference between the battery tender plus and bt jr is the charging rate. 1.25 amps for the bt plus and .75 amps for the bt jr. To maintain the battery charge for the winter the bt jr should do a great job. Also if you hook up the lighter adapter you can move from car to car with ease, assuming it has a power outlet.

Resurrecting an old thread but my Cayman arrived last weekend and I started to attach the Battery Tender to the battery the same as the OP. I started with the positive terminal and it was very tight...I should have known better than to try and put it back on. When I did the square end of the bolt dug into the soft lead terminal and started spinning. I ended up snapping it off just to get it back apart. I repaired it with a stainless bolt/nut from the hardware store but I also thought I would be able to get a replacement. I think it will take a while for my OCD to forget that I have the wrong bolt under there! While I was under there I found my battery vent hose that was not connected and the angled piece on the battery wasn't there (this is not the original battery , my Cayman is a 2006). I did find where I can purchase that OEM part.

I also found that the felt anti-corrsion items that go under the terminal were keeping the positive terminal from seating far enough down on the post. They were keeping it up high enough that it wouldn't tighten properly. Removing that after-market item allowed the terminal to seat down to the bottom of the post and then it would tighten and hold.

I know this is an old thread, but I discovered the exact same issue with my 2006 Cayman S . Upon close examination of the bolt (after I finally got it out), I noticed the end had been punched as if to flare it out. I believe the idea is to make the nut captive so you can't accidentally remove it and lose it somewhere into the bowels of the front of the car. In short, I think it's intentional. And yes, you do destroy bolt if you take the nut all the way off. The nut doesn't fare to well either. For some reason, this is more extreme on the positive side then on negative. What one needs to fix the problem is an M6x1 20mm square head bolt. So far I have not found those. My backup plan was to buy the negative cable (and scavenge the terminal and bolt) as it's ony about $16 from various Porsche dealers online — however that plan was thwarted when I noticed that my cable has been superseded by a 997 part of a different design. No bolt and nut to scavenge. in the mean time I used an M6x1x20 flange bolt and used my dremel to flatten one side of the flange. Works perfectly, but I too am a purist and want to find the right fastener. My search continues….

I had absolutely no trouble backing the battery cable nuts off all the way to install my battery maintainer ringlets. The bolts screwed right back on and were not damaged in any way. The bolt gives up before the nut and it's been this way on my car for 7 years. In fact I just removed the ringlet connections from the battery because I use a different maintainer now with the cigarette lighter plug . The only change I saw was that the nuts are no longer captive with the bolts and now work as regular nuts and bolts.

As I've researched finding the right replacement bolt (difficult in quantities of one or two), I've discovered posts on several Porsche forums about the this issue. It seems there is some variation in the 'captive' process — some people remove it and it works fine, and some not so lucky. My experience was split; the negative side fasteners behaved as you described; the positive side behaved as the OP. On the positive terminal, the nut turned very smoothly until it came to the end of the bolt; for the last 1/16 in it required so much torque to turn, I knew the threads were getting hammered. Sure enough the nut removed at least two rings of threads on the end of the bolt. BTW -- closet thing I can find (so far) for a replacement is VW N0174052. It seems to be M6x38, which would be a bit long for our use.

I wish I read this thread prior to installing my battery tender "rings." Btw, first post! I recently bought my first Porsche . It's a 2007 base cayman . 3rd owner, 52k miles, manual. I had significant difficulty removing the positive terminal nut and bolt and moderate difficulty removing the negative terminal nut and bolt. I was able to reattach the negative terminal bolt with the battery tender "ring" inserted. However, upon trying to reattach the positive terminal nut and bolt, the square headed bolt dug into the softish battery terminal. I ended up using needle nose pliers to hold onto the square bolt and a socket wrench to remove the nut and bolt. The positive side nut and bolt were unsalvageable. I searched far and wide for a replacement nut and bolt...none available. Found a 1 dollar solution at home depot . Got a M6x1x30mm hexagon bolt (zinc plated) and nut (stainless steel), and they worked nicely. 30mm is a bit long, 20mm would have been perfect. Upon securing the terminal with the nut and bolt, the bolt did continue to turn as I fastened and didn't "Grab." This was because I had stripped the soft terminal end from the square bolt. Perhaps if I used a friction washer, or a flange bolt and cut it (like kevinr), I could have avoided this. Instead, I used needle nose pliers to secure the hexagon bolt and a socket wrench to fasten the nut. The photo with the red battery tender "ring" shows the home depot solution. TLDR: Don't remove the OEM nut and bolt from battery cable. Instead, use the cigarette lighter to tend the battery . Anyone see a problem with using zinc coated or stainless steel as my new nut and bolt hardware? Hope this solution lasts!

Oh well hell, add me to the wall of shame!!! I too found the positive terminal bolts and nut to be tight and cross threaded upon removal just for the battery tender ordeal!! To heck with it, home depot new stainless steel bolt and nut and this ended the drama quick. Shoulda, coulda woulda. I too was thinking about the cig lighter connection, just thought this would be faster than the MacGyvering the cig lighter adapter method.

i think that's done intentionally to discourage people from wrenching.(translation:bring it to the dealer so they can overcharge you.) Bimmer does the same thing.