After a spirited drive to collect takeaway on Saturday night on returning my car wouldn't start. It turned over very slowly and power had drained giving that 'verrrr-um' noise and nothing else although I have dash lights. The needle says battery power stands below 12, I'd say maybe 10.5 and having to get a rather embarrassing bump start by a bunch of lads I drove home rather gently and the needle didn't improve at all. After turning the engine of it wouldn't restart again, again I have dashboard lights and some power. I'm assuming (and hoping) it's the batter and not the alternator so googled ideal 996 battery and came up with this

https://www.design911.co.uk/mobile/#part;id=826

And wondered if this is the right battery for my c4s cab. At almost £100 or around $150 I don't want to get something that's underpowered and found a cheaper site to design 911 seemingly offering the same battery for about $25-$35 less

http://www.carparts4less.co.uk/cp4l/p/////?444771107&0&cc5_998

http://www.eurocarparts.com/mobile/ecp/p/accessories-car-batteries/car-batteries/most-popular-car-battery/110-car-batteries/?444771107&0&cc5_998

Thoughts on this battery would be appreciated and is anyone else using this or which alternative?

 

Take the battery out and have it tested at a garage, or it could be the alternator. I'm really thinking the alternator though.

 

I've been going through the same thing lately, how regularly do you drive your car?

If its driven daily id say check the alternator. If you don't drive it regularly do you leave it unlocked when you park? That will drain your battery. I find if I don't drive my car (04' 996 C2) at least once a week the battery will start to drain and go flat. My partner stalled at a set of lights and we had to get roadside to give us a jump. Got my ctek charger out (same brand that makes the Porsche Chargo-Mat ii) gave it a day to charge all good now!

Im thinking about getting a cheap volt meter for the f-runk and jump it off the luggage light so when I open it I get a nice voltage reading. Anything under 12 volts and I think the car wont start? (Dont quote me though)

 

Get your battery checked out FREE at Pep-boys. If it is good then go the Alternator route. A battery last about 5 years and Pep boys will tell you the age of your battery when they are testing it. If it is bad, get a new BOSCHE from them at just over a hundred dollars.

 

the guy is in London, doubt if many, moe and jack are over there..

 

Really hoping it's not the alternator and another £600 outlay. Having googled a trawled the forums I've read about issues of a wire from alternator to starter motor with corroded terminals, anyone had this problem and is this likely?

Also, if I disconnect the battery and take to shop for testing won't I loose settings, radio etc etc?

 

Don't aimlessly throw parts at it. The alternator cable is a common failure. Get a voltmeter and check before and after the alternator cable. If it's the same voltage, then move onto the alternator.

Sounds like either the cable or alternator to me. The fact that you were able to jump it and keep the battery charged while you drove home is sounding more and more like the cable.
If it was only your battery, your volt meter would've jumped up to 13.5-14 volts once started with a good alternator/connection.

 

Id defiantly second that. Test the battery voltage. How regularly do you drive the car? For me if mines sat for 2-3 weeks it will start but the battery is actually flat and only has one start in it. Get yourself a good trickle charger if it's not a DD

 

Thanks for the info Alpine and Dan, I'll cable jump it tonight and take it to the shop for a drop test rather than remove the battery for fear of losing the radio codes.

The cars pretty much a DD, driven 4-5 days a week as opposed to sitting for days/weeks on end. Admittedly Saturday consisted of a few stop-start journeys and didn't really go beyond 3 miles between switching off the ignition. Saturday evening was a 30 mile round trip and hit 125mph in part racing the motorways between towns then wouldn't restart. Once push started the return journey was taken with care, no radio and side lights only. The dashboard meter was above 10 but well below 12 and occasionally seemed to drop lower then raise slightly rather than increase with each mile. On returning home I stalled her and she refused to restart again. Checke her last night, battery still sits around 10, hood and trunk still works from the switch which is fortunate - I'll keep you informed

 

In situations where the battery is weak I keep the car locked but the hood and rear lid ajar so if the battery dies I can still get in without having to use the release cables or hook up a jumper to the fuse box (That is if you have a garage and dont keep it on the street!)

 

Find the radio codes for the car. You will certainly need it one of these days.

 

If your battery is more than a few years old, you'd probably want to change it anyways as to not get stranded. Being that you're in England, generally being more corrosive to parts, I'd clean the cables and connections even if the cable checks out fine. Good luck

 

The voltage regulator on the Alternator can also go bad and can be replaced. My alternator was fine but the regulator had gone. Also the Y cable that goes from the alternator to the starter is a known problem. they can look great but the cable will be corroded inside.