battery cut off switch - 986 Forum - The Community for Porsche Boxster & Cayman Owners

jhandy · 01-06-2010, 09:39 AM

Hi, I wanted to get one of those battery cut off switchs that still allow a little power to the radio and CPU, but cuts off power to the battery.

The reason I wanted this is that when I park my car for a few days, the battery dies just enough not to start the car, but enough to open the trunk.

My question is: If I put this on, pull the plug, and then shut the hood, will I be able to open it again without pulling the cable?

Any other ideas on fixing the problem of battery drain?
I already did the testing on the car with a volt meter, and nothing pulls a ton of power, but I think that combining the radio, CPU, alarm, alarm indicator lights drain the battery.

James

yimmy149 · 01-06-2010, 09:44 AM

Park your car for a few ____?

If it's days, then there is something wrong with your car and/or battery. My '01 S can be parked for a few weeks and will still start.

I haven't seen a switch that would only disconnect certain items. Plus, I don't think you would want to have the engine relearn it's curves every few days.

If you have an outlet nearby, you could look into buying a battery maintainer. Porsche has one. I am using a CTEK 3300.

-james

mikefocke · 01-06-2010, 10:00 AM

of sitting with no use and no special battery charger/maintainer. I have no aftermarket accessories. I'm parked with the doors unlocked. The Boxster generation is smart and lots of things turn off after a time so as not to drain the battery.

Any idea how old your battery is? When you do drive the car, how far do you drive it and are all the accessories (lights, stereo, a/c, etc) on when you drive it? An aftermarket stereo drawing extra power when on perhaps? Any hardwired GPS, battery chargers, radar detectors?

My bet is you need to have your battery checked with a load tester. I'll bet it is unable to hold a full charge.

Dave928 · 01-06-2010, 12:15 PM

it's just a normal cut-off switch but with a .5A fuse going around the switch, just enough for radio and ECU memory but any bigger draw will pop the fuse and save the battery charge.

Quote:

Originally Posted by yimmy149

I haven't seen a switch that would only disconnect certain items. Plus, I don't think you would want to have the engine relearn it's curves every few days.

sd_boxster · 01-06-2010, 04:21 PM

^ If that's the kind of thing he was asking about, that wouldn't solve the problem anyway. If he's got a parasitic draw on the battery that takes a few days to drain down, it's probably not going to blow a 500ma fuse.

It sounds like you need to have your battery tested... And if it's bad, think twice before shelling out the bucks for a Porsche battery. My AutoZone battery works perfectly and fit perfectly.

Roxy · 01-07-2010, 01:15 AM

Take the car to an auto electrician and he will check current draw.
If you have access to a multimeter with a fused 10amp test facility, turn everything off remove the keys depress any alarm switches or light switches that are active when the front bonnet is open and check voltage and current draw between the + battery lead (disconnected from the battery) and the battery terminal. Have the battery tested with proper current test equipment.
Roxy