Having had months of battery problems, I have some adviuce to offer, but also some questions I still need answering.
Battery going flat - solutions:- trickle charger plugged into mains (I suggest Halfords). If you get one that plugs into your ciggy lighter, you need to get the wiring changed on the car so the cig lighter is live after you turn things off (apparently normally all circuits are shut down after switch off)- solar panel charger. I had to go for this as I park on the street. Not sure how effective it is, but its my only option. I got mine from the really nice chaps at Select Solar:
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Battery going flat - why?- I use my car sparingly (2x20min journeys during the week, 2x30mins at weekend)- Even with a brand new Porsche battery (£130 thank you very much) I had major problems with it draining in winter (summer isnt as bad due to atmospheric pressure)- Even after a 1hr drive on the weekend, 5 days later its flat and setting the alarm off- 4 OPM's and 3 independents told me this isnt great, but is certainly not out of the ordinary. When I asked them what I do when I go on holiday for 2 weeks, they had no answer. Great, very helpful.- OPM diagnostic expert had my car for 5 days and cant find anything wrong with it (drain is around 0.078A, charge rate is okay apparently)
Useful things to know:- a well charged battery should read around 12.2v on the guage (or your voltmeter) when engine not running. Mine commonly reads lower than 12v after being left ofr a few days- with engine running, battery charging is indicated by guage reading in excess of 13.8v- standard operating voltage with engine running (when batt charged) is around 13.8v- If you have a tracker, you should always charge the car battery fully connected in the car, as you need to charge the tracker batt's at the same time.- when getting a batt charged by a garage, check if they have a 3-phase charger (it really sorts things out and is the best way of charging a batt, but does take up to 48 hours)- A flat battery needs at least a 2hr drive in the car to charge it, with some solid drives in the following days. Don't jump it, do a 30min drive and think you'll be fine.- read your manual and connect jump leads to engine, as specified
Tracker:- I have a Tracker installed and it is the only thing I havent had fully tested yet- tracker insist there is nothing wrong with it, but if its batt's have discharged a few times, and they are 3.5yrs old, it could be that they dont last very long and once flat they create a large drain on the car batt, or start shorting it- Tracker coming to investigate next week (£80 call out, again delighted)
Questions:- anyone else suffer this poor battery life? (assuming low levels of car usage)- anyone figured out how to put a battery disconnect switch into a 996? (difficult as it messes with the alarm)- anyone figured how to disconnect battery but lock all car doors (I dont mind the alarm being off, but cant leave it unlocked on the street!)
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