Battery drain

[FA-18C]

Have read the past posts on battery drain, I think I may just have old batteries, but am going through the drill. Question is whether I need to disconnect BOTH batteries +/- terminals to isolate faults? Also, if I end up having to buy a new battery I will likely go the Optima route, and use one battery. What is the best way to insulate the unused staboard side battery cables? Also, if anyone's moved the battery to the smuggler's box I'd be interested in hearing how you routed the new battery cables. Of course if i do this the Webasto must go...
thanks
Chris
1970E

[Joeaksa]

Chris,

I WOULD NOT put the battery in the smugglers box. One nice thing that the battery in the very forward part of the car does is to try to offset the heavy lump in the back end of the car, otherwise called the motor!

Remember working weight and balance with your IP when you were in Pensacola? Works the same in the 911 and moving the battery aft a couple of feet will shift more weight to the rear, which is not a good idea.

I know that you are not going to "run out of stick" with the weight shift, but every little bit helps when it comes to getting closer to a 50/50 weight mix. Keep it forward and your handling will be a bit more reasonable.

Cannot help you much on the other part of your questions other than to say that I have the same type of battery on my bike and love it. Cured lots of issues and would be nice in your situation as it does not ever leak and the early series cars can be a problem with rust in these area.

Re your question on insulating the old terminal, I would to go a good electronics shop and get some shrink tubing. They make it in various sizes and get some, put it over the unused battery terminals and heat them to shrink over to cover and secure them somewhere with wire ties.

Fly safe, check six..

[FA-18C]

Thanks Joe, seems you speak fighter puke as well, nice to have a translater when the discussions get to technical for a simpleton like myself...understand the weight balance issue, was planning on corner weights, but in hind site will just omit one battery and press on, maybe even put a sand battery case in the other side...good idea on the contactors...
On a brighter note, had the opportunity to fly out and escort in my Airwing returning from deployment for photo's...nice to have them back and a proud moment for thousands of families.
Chris
70E

[Joeaksa]

Chris,

Spent a few tours overseas in the past. Berlin, Saudi and such, been there and would go back tomorrow! Hell, I wish I was there now!

Re the battery, in the old days, possibly even with your car, Porsche even went so far as to put lead weights in the bumper to shift the weight forward. My feeling is that this was partly done out of liablilty and partly to improve handling. Most of these weights have since been removed and we do not see 911's spinning backwards off of the roads on a daily basis so its not really needed for safety. Your shifting weight with the battery is doing the same thing.

Remember as well that you weight shift anytime you have a passenger it the car. One good question is which corner to put the battery? I would think that its better to put it in the left hand corner, closer to the fuse/ele panel. On the other hand, putting it in the right front corner would partially offset the drivers weight, as most of us drive alone much of the time. Not sure and this is a question you might put up to the board and see their comments.

For normal street driving you should not notice a big difference, but if you want to push the limits (a fighter puke... push the limits?) in the car you would be well advised to set the car up the way you like and want it, then get it weighed on each corner and match them up. Any good performance shop does this.

Your car was probably set up in 1970 and likely is way out of rig now considering the age of the torsion bars and such. Pulling 30 pounds out of both corners in the front and replacing it with 40 pounds in just one corner will result in an partial unbalance situation.

You could notice this in cornering but more likely in heavy braking as the same pressure is not being put on both front corners. Again, this will not show up under normal driving but when you are working with the suspension (you are not driving on 30 year old shocks are you??) and such this should be done to equalize everything.

Put it on the list of things do to after shocks, torsion and sway bars. Remember about weight shift and everytime you fill the gas tank you are shifting more weight than we are talking about with the battery, so do not worry a lot about this.

I would try not to use ballast to offset the weight shift, as any extra weight slows the car down. You might look to putting a ligher decklid in the back or reducing weight elsewhere to achieve the same result but Porsche has already done most of the things possible to save weight. Of course then the styling people got ahold of the car and keep adding things to sell the car, so its a give and take situation. Porsche did not put aluminum lug nuts on the car for decoration...

My brother was on the Oriskany and Phil Sea. Family has a long history of traps and such but I ended up in a different type of flying. Tell you about it sometime over a beer... would form up on your wing anyday!

Saw the "Big E" return on the news and bet they are happy to be back. Glad you were able to help with the escort. Are you going back out on the boat?