Notices
996 Forum 1999-2005
Sponsored by:

New Bosch Battery: Much Better than Interstate

Thread Tools
 
Search this Thread
 
Old 04-27-2016 | 11:57 AM
  #46  
Long Islander's Avatar
Long Islander
Racer
 
Joined: Mar 2003
Posts: 474
Likes: 29
From: Long Island (New York)
Default

Originally Posted by Quadcammer
taping that hole will not work. there is really nothing to tap. I tried this and the one thread or so I got on there stripped immediately.

That said, this is very simple.

Find a bolt that fits snugly through the hole in the hold down bracket, drill the hole in the tray to match, and then put a nut under the tray and hold it in place with a wrench as your tighten down. You'll want a bolt approximately 25mm long.

Alternatively, you could take the tray off and either weld or epoxy a nut onto the tray.
Thanks for the heads-up on tapping a thread into the hole. I don't think epoxy is going to hold a nut enough to withstand the torque that is put on it. As an experiment, I took a similar size nut as the ones that hold down the battery tray, and I epoxied it to a piece of metal using two different epoxies. After allowing it to cure, the epoxy did not hold up to a small amount of force on the nut.

I called a local independent Porsche specialty shop to see how they install H-8 batteries in 996's and Boxsters. They said they just hold a nut using their finger underneath the battery tray on the non-threaded hole and tighten. But they did say they could weld a nut for me for $20, which seems like the best way to go.
Old 04-27-2016 | 12:27 PM
  #47  
5CHN3LL's Avatar
5CHN3LL
Race Director
 
Joined: Sep 2012
Posts: 10,423
Likes: 214
From: SOcialist republic of CALifornia
Default

Use a jack nut.



*edit* Less massive image
Old 04-27-2016 | 12:31 PM
  #48  
Long Islander's Avatar
Long Islander
Racer
 
Joined: Mar 2003
Posts: 474
Likes: 29
From: Long Island (New York)
Default

Originally Posted by 5CHN3LL
Use a jack nut.
Interesting. How does that work?
Old 04-27-2016 | 12:35 PM
  #49  
5CHN3LL's Avatar
5CHN3LL
Race Director
 
Joined: Sep 2012
Posts: 10,423
Likes: 214
From: SOcialist republic of CALifornia
Default

Just like a an expanding wall fastener - you drill a slightly larger hole, insert the jack nut, and tighten the bolt. As the bolt tightens, the ribs collapse and increase the diameter of the body of the jack nut enough that it locks the nut in place. The divots around the perimeter of the jack nut are there so you can grip the nut to keep it from spinning during initial tightening.

You've probably used one of these to hang up a curtain rod or something...same principle.

Old 04-27-2016 | 12:38 PM
  #50  
Long Islander's Avatar
Long Islander
Racer
 
Joined: Mar 2003
Posts: 474
Likes: 29
From: Long Island (New York)
Default

Originally Posted by 5CHN3LL
Like a drywall expansion bolt - you drill a slightly larger hole, insert the jack nut, and tighten a bolt. When you insert and tighten the bolt, it causes the ribs to collapse outward, increasing the diameter of the body of the jack nut enough that it locks the nut in place.
Seems like a nice and simple solution.
Old 04-28-2016 | 01:40 AM
  #51  
DrMEMS's Avatar
DrMEMS
Thread Starter
Instructor
 
Joined: Oct 2010
Posts: 244
Likes: 3
From: SF Bay Area, California
Default

Originally Posted by wyovino
"And my new Bosch AGM battery does appear to have a vent hole. "

Did you hook it up? I was under the impression that AGM batteries were sealed and didn't need venting.

How can something as simple as replacing a battery be so complicated?
The instructions said that this AGM battery is sealed, but:

Below are photos of the left and right sides of my battery. The hole on the left is open. When I bought the battery, it had a drop of sulfuric acid in the hole (sulfuric acid looks different than water, having a higher index of refraction, and doesn't evaporate very fast). Now you can see sulfate-looking residue. The right side came with a plug.




Old 04-28-2016 | 08:00 AM
  #52  
jhbrennan's Avatar
jhbrennan
Rennlist Member
 
Joined: Mar 2006
Posts: 6,571
Likes: 81
From: Austin
Default

My Bosch AGM had an elbow attached to the unplugged vent hole on the positive side to remind me to hook up the vent hose.
Old 04-28-2016 | 09:10 AM
  #53  
Sneaky Pete's Avatar
Sneaky Pete
Nordschleife Master
 
Joined: Nov 2008
Posts: 5,815
Likes: 55
From: Mooresville, IN (Life Long Cheesehead)
Default

6 pages about a battery?
Old 04-28-2016 | 12:23 PM
  #54  
jhbrennan's Avatar
jhbrennan
Rennlist Member
 
Joined: Mar 2006
Posts: 6,571
Likes: 81
From: Austin
Default

Originally Posted by Sneaky Pete
6 pages about a battery?
Almost like oil or IMS discussions - search battery and you'll find more than 6 pages.
Old 04-28-2016 | 12:49 PM
  #55  
RGrove's Avatar
RGrove
Rennlist Member
 
Joined: Aug 2013
Posts: 233
Likes: 5
From: NW Suburbs of Chicago
Default

Originally Posted by DrMEMS
The instructions said that this AGM battery is sealed, but:

Below are photos of the left and right sides of my battery. The hole on the left is open. When I bought the battery, it had a drop of sulfuric acid in the hole (sulfuric acid looks different than water, having a higher index of refraction, and doesn't evaporate very fast). Now you can see sulfate-looking residue. The right side came with a plug.
Even though AGM batteries are sealed, they do have a vent valve in case of excess pressure build up (i.e. due to overcharge condition, etc), similar to a water heater safety valve. In the event that valve is used, the excess hydrogen gas needs to be vented to the atmosphere.
Old 04-28-2016 | 01:03 PM
  #56  
5CHN3LL's Avatar
5CHN3LL
Race Director
 
Joined: Sep 2012
Posts: 10,423
Likes: 214
From: SOcialist republic of CALifornia
Default

Originally Posted by RGrove
Even though AGM batteries are sealed, they do have a vent valve in case of excess pressure build up (i.e. due to overcharge condition, etc), similar to a water heater safety valve. In the event that valve is used, the excess hydrogen gas needs to be vented to the atmosphere.
Yup. Connect the clear plastic tube to the hole nearest the tube, and use the plastic plugs to plug the other holes to ensure any hydrogen vents out the tube rather than accumulating in the frunk area.
Old 04-28-2016 | 02:25 PM
  #57  
DBJoe996's Avatar
DBJoe996
Rennlist Member
 
Joined: Apr 2010
Posts: 5,962
Likes: 1,198
From: Ormond Beach, FL
Default

I routed my vent hose to the fuel tank so I get hydrogenated fuel...good for at least 30-40 HP more I figure. I also keep my used batteries and throw them in the pool. The slow drain of sulfuric acid keeps the water pristine.
Old 05-07-2016 | 04:48 PM
  #58  
Long Islander's Avatar
Long Islander
Racer
 
Joined: Mar 2003
Posts: 474
Likes: 29
From: Long Island (New York)
Default

Originally Posted by jhbrennan
I recently replaced my tray and the part I received had all the holes threaded. Here's the part number:

99750415100 BATTERY CARRIER

Replacement went into a 2004 996 C2.
I checked with a local Porsche dealer and that is indeed the part number for a 996 C2 and he verified that it has 4 threaded holes. Strangely, the part number for a 996 C4 is 997504415101, which also comes with 4 threaded holes. Unfortunately, they are pricey. The best price I got was $138 plus shipping.

Instead, I had a nut welded to the bottom of my tray. See photo. The nut is the same size as the threaded holes, and the original bolt fits just fine. Problem solved.
Attached Images   
Old 05-08-2016 | 02:49 AM
  #59  
porschemikeandnancy's Avatar
porschemikeandnancy
Pro
 
Joined: Jan 2002
Posts: 552
Likes: 0
From: Greater Seattle (via NH)
Default AGM Batteries for 996s

I purchased an AGM (absorbed glass mat) battery to replace the relatively new battery I received when I purchased my '03 996 C4 Cab in Feb. 2015. The dealer told me: "we just replaced the battery". In fact, it was the smaller size - which fit against the first battery tie down hole under the battery platform. And I used a battery tender and the thing still would often barely start the car.


https://en.wikipedia.org/wiki/VRLA_b...d_glass_mat.29

At my indie on my last oil change, the very experienced tech saw the battery and commented: "oh that's one of those new glass mat jobs - they are very good batteries".

I purchased it at Batteries plus Bulbs. I wasn't aware that this place even stocked auto batteries. The specific store I bought it at really didn't know how to physically "tie down" the battery as (reported in this thread) the larger battery did not align with the first tie down hole. My indie tech simply added a nut under the battery tray into which the bolt and the tie down metal plate attached securely.



Quick Reply: New Bosch Battery: Much Better than Interstate



All times are GMT -3. The time now is 04:26 AM.