Dead Battery

[wjschneiderjr]

Can anyone help me with a battery going dead issue with an 01 Boxster S? Can't seem to find the problem. Car will be ok sometimes and other times the battery may go dead overnight. Doesn't seem to matter whether the car is locked (security on) or if it is just sitting in the garage unlocked (no security). Checked the obvious things like lights staying on in trunks, made sure all the lights is passenger compartment go out after a min or so, etc. Can't seem to find it. Recently replaced the battery as I thought the battery was just bad. All seemed to be ok for a week or so. Last night put the car in the garage and put a Battery Tender on it overnight. When I checked on her this morning the Tender was very warm and the "charging" light was still on. Nevertheless I tried to start the car to get an idea if maybe it was close to being fully charged. Car wouldn't even offer to turn over. Just clicked and reset the clock, trip odo, etc. Put a meter on the battery and voltage was around 7.5 volts. All this after being on Battery Tender for several hours??? Any help from anyone would be appreciated.

[mikefocke]

Lets assume there are no aftermarket stereos, radar detectors, iPod chargers or the like.

I'd reinstall the battery cable clamps and reset the grounding strap where it contacts the frame.

I'd recharge the battery and then load test it. Inspect its fluid level. Reinstall. Now see what happens.

disraeli posted this on PPBB

"The factory technical manual (Section 97-07 page 2) has the following table of total electrical load after the car has been shut off (ModelYear 02):

(electrical current is worst case, i.e. car loaded w/all options...)

FROM TO mA

0 min 5 min up to approx. 950

6 min 15 min up to approx. 900

16 min 20 min up to approx. 750

21 min 60 min up to approx. 50

61 min until the battery is empty up to approx. 30

1000mA equals, of course, one amp.

If the car had no options whatsoever, the load after 60 min would be 17mA instead of 30mA.

From this table you should be able to insert a meter between the battery and battery cable and tell if the car is within spec before you begin pulling fuses or removing the battery to get it tested."

If there are still problems, then you have to isolate the problem circuit and you do that my removing one fuse at a time and putting a multimeter across the connections and seeing if there is current draw with the ignition switch off.

[wjschneiderjr]

Lets assume there are no aftermarket stereos, radar detectors, iPod chargers or the like.

I'd reinstall the battery cable clamps and reset the grounding strap where it contacts the frame.

I'd recharge the battery and then load test it. Inspect its fluid level. Reinstall. Now see what happens.

disraeli posted this on PPBB

"The factory technical manual (Section 97-07 page 2) has the following table of total electrical load after the car has been shut off (ModelYear 02):

(electrical current is worst case, i.e. car loaded w/all options...)

FROM TO mA

0 min 5 min up to approx. 950

6 min 15 min up to approx. 900

16 min 20 min up to approx. 750

21 min 60 min up to approx. 50

61 min until the battery is empty up to approx. 30

1000mA equals, of course, one amp.

If the car had no options whatsoever, the load after 60 min would be 17mA instead of 30mA.

From this table you should be able to insert a meter between the battery and battery cable and tell if the car is within spec before you begin pulling fuses or removing the battery to get it tested."

If there are still problems, then you have to isolate the problem circuit and you do that my removing one fuse at a time and putting a multimeter across the connections and seeing if there is current draw with the ignition switch off.

Thanks for the reply Mike. Went thru and checked as described. Connected a multimeter between battery and battery lead and found the current draw to be as outlined by the manual. Checked battery, terminal ends, ground attachment points, etc. Everything seemed to be ok. Drove the car a couple of times and no problem. Took my truck to work yesterday and planned to take the Boxster out to dinner last evening. Car wouldn't start and battery voltage was low again. Charged the battery overnight and proceeded to test again this morning. Today I found a power draw of 2.81 amps! This even after being idle for an hour or so. My wife was home so I enlisted her help to watch the meter as I painstakingly removed each fuse one at a time from the fusebox. Oddly enough no change even after all the fuses were pulled and laying in a pile on the floor. ( I did this reaching over the door so as not to confuse my issues with the interior lights being on.) What gives here? Is there another fuse box somewhere in the car? When I put the key in the switch and turn it to "on" the power draw increases to 2.91 amps. Only after the key is switched "off" and removed does the draw reduce to the previous 2.8 or so amps. Apparently my problem is intermittent but what could be causing so much draw with the fuses all removed? I would have thought with all fuses pulled the battery is effectively removed from the car. No? Very confusing. Don't know if this is any clue to my problem but my driver's seat (power)will not adjust. When you move any of the switches a faint click can be heard but no movement of the seat whatsoever. Fuse is good for the seat so maybe a relay could be bad. I have had this problem for some time but didn't bother to repair yet as no one drives the car but me and I'm tall. Thought maybe I should pull the seat and check connections, grounds etc under the seat but unable to reach the rear bolts because the seat is all of the way back. Once again, any help from anyone would be appreciated a great deal.

[Steve Tinker]

According to my Bentley Boxster Service Manual, and assuming you pulled ALL the fuses out of their receptacles in the fusebox (located in the footwell), there are no other fuseboxes apart from the "current distributor" located high in the bulkhead above the right seat - though I would doubt any problem there, as it would show up in other ways.

The only other fuses I could see is in the anti theft control module under the left seat and the secondary air pump fuse in the relay panel #2 in the rear boot (err, trunk in your language). You would think that these secondary fuses would still be protected from the main fusebox though.

I'm just wondering if you have a problem with your ignition switch as the current draw from being OFF @ 2.8 amps to ON @ 2.91 amps is very little. These switches are known to be problematic after a few years.

If you have access to the Bentley Service Manual it would be a great help to you locating the electrical componants....