Vlocity

I spent almost all day yesterday going through every bit of the car that I could get to. I installed a battery shutoff switch (seperate thread) and a designated accessory plug so that it was easier to plug in a battery tender.

I have the battery switch in the off position and the voltage was 12.57 this morning, the same as it was after charging it. So, that looks good so far.

I checked the wires to the starter the best that I could with a mirror and by feel and they appear to be just fine.

What I did find was that the passenger side dome light was possibly not seated correctly. Although it was operating, I found that it was not seated in the lower tab. WHO knows ? But it was something.

The other thing that I found was that the passenger window switch (on the drivers side) was broken. It works but had "popped out" a bit, I have removed the switch until the new one arrives. I don't think that the windows are energized with the key off, but again, I am trying to be thorough.

I'll post the results after a few days.....and I still may go and buy an appropriate larger battery. I have found a Group 48 battery with 130 minutes of Reserve Capacity (75 Ah). The Optima I have now would equate to about 78 RC or 48 Ah.

Thanks again to all for being a sounding board.

Ken

darth

Ken

Although switches are convienent I caution against using them in hi current circuits, where you want to limit the number of connections (i.e. and potential problems) to a minimum and transfer maximum power to the starter or from an alternator. Switches have inherent resistance even when new and are subject to degradation around lead acid batterys where sulfides tend to build up and arcing can occur due to the hi currents. A typical battery has to supply 500amps to the starter at 12volts and if the switch has a resistance of a mere 0.002 ohms that would create a 1 volt drop. Also, one can get complacent with hidden switch connections as opposed to having to undo a very visible connection which is secured by a bolt. The battery is one of the places one does not want to become complacent, theres a lot of electrical energy stored and it can make a heater wire even out of the starter cable.

Just my 2 cents worth
Bill

Vlocity

Well I checked the car this moring in the 13 degree temperatures and the battery voltage was holding at 12.45, it started right up and this is day 5 since the battery was charged with only one short 3 mile drive in the mix two days ago.

As noted I found that the passenger side dome light was not seated correctly and believe that was the issue causing the drain. The other item was the window switch which I fixed on Monday with a replacement....it could have been the culprit, but less likely.

Bill, your concerns are noted. The switch I am using is rated at 210 Amps continuous and 600 Amp surge. I have had one like it installed in my 928 now for over 10 years. We see this type of switch on every race car that comes to the track and I'm not aware of any failures or issues. I would prefer to be able to kill the battery quickly in an emergency . The additional benefit for storage is that I would perfer to have a car with the power shut off, rather than place a battery tender on it for long periods of time. There is much more potential for disaster in that scenario.

Thanks everyone for your help.

Ken

darth

Ken

Has the battery been disconnected or connected through the switch during this time or any of the time? If it has been connected, then it appears you've solved the problem and persistence has paid off for you !

Bill

Vlocity

Bill,

Yes it has been connected since Saturday !!! (5 days)

Thanks for all of your help.

Best regards,

Ken

darth

My pleasure and thanks for keeping us informed to conclusion. Often times we never hear of the final outcome.

Have a Merry Christmas
Bill