Battery scare

Hi Folks Monday morning got in the car and battery flatter than the proverbial. My fault, I think. I left the TomTom iPhone mount plugged into the cigarette lighter socket for a few days, thinking that if the iPhone wasn't plugged in, the unit wouldn't draw very much power. I could be wrong but it's the only variable I can think of right now. Jump started the car from one of the other cars and took it for a lengthy drive. Battery seemed fine when I got back and has been "OK" since. However, I've noticed that when driving, the guage says just under 14 and, when I start her up, especially in the cold garage in the mornings, as the starter turns the engine, the needle drops down to under 10, on the way to the bottom of the guage, then goes right up back to just under 14 as soon as the engine fires up. Is this all sounding fairly normal, or does it appear that the battery is weak and needs replacing? Cheers Chris

Sounding a little like my scenario, before it died and needed replacing.

Sounds pretty normal Chris. I've got a brand new battery in mine & that's what I see too. The real test of a battery is can it give decent current for starting whilst maintaining a reasonable voltage (you don't mention that it's struggling to turn the engine over) and can it hold a charge once it is charged. I would just monitor the situation . I've got a 2 year old Moll that is getting a little tired (but it's still fine) if you want to try a swop out.

Hi Jon, Nick Thanks for the fast replies. This is my first 911 so not sure how fast the motor is supposed to turn over when cold, in that initial turnover, when it's "normal". Sounds OK to me, if perhaps the first turn or two are maybe a teeny slow, but then again maybe that's just what it is like as the norm!? Since the panic run on Monday to recharge it, I've driven the car every morning and so far she has started each time. Wondering if I should now leave 'er in the garage for a couple or three days and then try again.... All the best Chris

Hi Chris. The gauge readings are normal. Your alternator should put a charge of around 13.7 volts in to your battery when the car is running; hence the 'just below 14' reading that you're getting at idle. The volt metre reading will nearly always drop down when you turn the car over - especially when it's cold as the battery has to work that much harder to turn the engine over. Don't forget; you've got a big engine - six cylinders and big displacement. Frankly you're lucky that your battery is just 'ok' now as you run a very high risk of bending/knackering one or more of the lead plates/cells in the battery if you try to work the battery really hard whilst it doesn't have much of a charge in it. The usual scenario is that the lead plate nearest to the +ve terminal gives up and then you'll only have the remaining five cells to play with - which is never enough. The result is that your alternator then has to work extra hard to get a charge in to the battery and you end up breaking down in the back of beyond and have to get your wife to help you push the car to one side on a busy petrol forecourt whilst a load of blokes in Saxo's laugh at you and all blow their horns in unison. Oh no, sorry, that was what happened to me! Don't do what I did and just keep thinking that the alternator will keep things safe for you. I ended up not only having to get a new battery (£100) but a new alternator as well (£350) - all because I couldn't be ar*ed to put a decent, slow charge in to the battery using a proper battery charger. My car is hardly ever used and this can be a recipe for disaster if you don't constantly have the car on a battery conditioner - which I now do! Do yourself a favour; no matter how "well" the battery currently seems, it'll be extremely grateful for a decent charge! Try to use a charger with a low amperage - say 3 to 5 amps. The longer and slower the charge the better the battery will be and it'll last you years longer!

Hi Adrian Many thanks for the detailed post. I have a Carcoon conditioner which I usually have connected to the battery of my little Transit Connect (it hardly ever gets driven these days so is just parked in the garage on the conditioner). Would the Carcoon be good for what you're recommending? Could I say drive the car tomorrow morning and then put it on the conditioner when I get back, then drive it again the next day and repeat the process, or would it be better to just not drive the car for a week and leave it on the conditioner the whole time? Cheers Chris

Hi Chris. I'm not too familiar with the Carcoon conditioner but I'm sure that it'll do the same job as my CTEK 3600. If you don't have access to a 'traditional' battery charger just leave your conditioner connected to the battery as often as you can over the next week or so. It'll bring the charge up slowly but surely. I'm guessing that the Carccon conditioner has some sort of charging indicator light or meter? If so, try to look at the charge level indicator before you even open the car up in the morning - this will give an idea of where you are with your battery charging level. I say before you open the car as the charger will probably read 'not full' as soon as you use your key fob or stick the key in the door as you're then drawing a (small) charge from the battery as the car starts running it's checks before (a predicted) start-up. If you can live without using the car for the next few days/week then you're only going to help matters by leaving the battery connected to the conditioner for any prolonged period of time. Failing that, if you do have access to a traditional charger - stick it on and slowly charge the battery until the amp meter on the charger tells you that you're not putting any more juice in to the battery. If you do this, the test will then be to see if the battery holds its charge under normal working conditions - assuming that your 911 is used regularly (every day or every other day). If it seems to be dying without any help from the charger then it might be time to think about visiting Costco for a Bosch Silver! If you don't use the car regularly I would seriously consider stealing the conditioner from the Transit for as long as possible - or better still get one for each?! I'm tighter than a gnat's chuff and even I'd say that it's got to be worth shelling out for one for the 911.[ ] Adrian.

I have both the Carcoon and Ctek chargers and the Carcoon will work fine except it will take a longer time for the battery to reach full charge compared to the Ctek XS7000 I have.

My cigarette lighter socket isn't live when I remove key - often wish it was - may be yours is different. Dave Jones

Mine isn't live either - this was not consistent between 996s. Some are and some aren't. I've hardwired the leads to the battery and the connector sits in the boot so no faffing about. Only thing is my CTEK has the new comfort connectors whereas the old one had the same connectors as the Carcoon so I could use either previously.

Thanks for the responses folks. Haven't driven the beast today and will see how "sluggish" the turnover is tomorrow morning. Will put the Carcoon conditioner on it over the weekend and leave 'er for a week or until the battery light is GREEN. ... Either that or... just go off to Costco and get another Bosch Silver battery. Anyone know the recommended model for 996 Turbo? Cheers Chris

Go for the Bosch Silver S5 010, which is 85Ah. The standard one is 80Ah in the Turbo. See here for instructions, and how to avoid the alarm going off: http://www.porscheclubgbforum.com/tm.asp?m=331718

Ta Richard In the event the Bosch Silver S5 is not available, would something like a Varta G8 be OK? Or... if you can recommend somewhere I can get the Bosch, I'd feel much more secure knowing it's the recommended battery. Cheers Chris

I'm sure the Varta would be fine. Perhaps give Euro Car Parts in Reading a call and see if they have the Bosch. Halfords stock Bosch Silver, which have a 5-year guarantee, and I have also heard good reports about their own batteries, which have a 4-year guarantee.

I use the Halfords Calcium battery and it has been fine for the last 2 years. I have a Halfords trade card which brought the price down considerably.

Hi Folks Lots of confusion here... the battery Halfords recommends when I put in my registration is list HERE . This battery is only a 77 AH battery which is less powerful than you've been recommending? Here are the details: Startup Power: 780 Amps AH Value: 77 AH Bench Charge: 6 Amps Weight: 18.65kg Dimensions (LxDxH): 278x175x190mm Guarantee: 5 Years Does this sound like the battery for me? I've looked for the "010", Richard but cannot get the Halfords site to dish it up without entering my registration number, at which point it reverts to the above battery? Whatcha think? Cheers Chris

The Bosch silver that Richard refers to was available at Costco. That is what is fitted to my 996. It isn't specifically listed for a 911 at Costco (I think it is for a transit van !) but the physical dimension is perfect and the Ah is fine for a 996 I would have thought that a 77Ah is fine as well. What were Halfords quoting ? I think My Bosch silver was around £90 at Costco. It was about a year ago i bought one. I think Varta do a similar one which is readily available on the net. Just google it Steve

In actual fact I have an S5 007 in mine, which is 74Ah and it's fine. I only used it because I had it "in stock" but it has coped perfectly well with cranking the car in the sub-zero temperatures last month. If I was going out to buy one, and I had a choice between the 008 (77Ah) and the 010 (85Ah) I would pay the extra and get the larger one.

Hi Steve Halfords online price for the battery is £119 which sounds a little high. However, I'm fairly stuck on getting the Bosch so will probably end up paying that for it.. Cheers Chris

The Halfords HCB096 or the Bosch Silver HSB096 is the battery you need.

Right! Off to Halfords. They don't have the 85AH only the 77, so will have a gander at other stock there before making the choice.

If you have a local Euro Car Parts , they will have it (or could get one) for about £75.

Here is a recommendation from a satisfied customer , try Tayna ltd (do a web search). Their prices are very reasonable and they deliver.

Thanks again for all responses to my original query. I ended up just getting down to Halfords and buying the battery. Will put it in the beast tomorrow. Cheers Chris

Jumping into an existing thread here- so apologies to the OP I've just got a 2004 Carrera 4 (picked it up yesterday and drove it 50 miles home). Had been serviced, and also had a full OPC service, including new battery 6ooo miles ago. I don't know how long it had been sitting at the dealers, but it seemed to have plenty of life in it when they started it, and during subsequent starts yesterday. I did do a few PCM setups with the ignition on, and the engine stopped, but notbing I'd suspect of being a big drain. Radio/CD and all lights were off. This morning it was almost dead- enough to turn a few turns then 'click,click,click'. An odd thing is that then the windows moved down a couple of inches and the spoiler extended. Voltmeter was showing nothing, but all warning lights were on. I've had to dash to work in another car so no time to test more, but is this just a very low battery, or something more radical? Will try jumpers later if appropriate. Thanks for any advice Neil

Sound like the battery to me.

I very much hope so! Thanks I do know the battery was left connected in the showroom, because the radio etc was working, but they were restricting access to those genuinely interested!

Hi Neil. I'm afraid that you battery is (maybe temporarily) dead. The window lowering and the rear spoiler extending are the results of a confusingly low amperage going to your OBC and the computer then telling the different things to do inappropriate things at inappropriate times, a bit like being really drunk - whatever that's like...[8|] Your battery may well have a duff cell. Can you get the tops of the cells? If so check the acid levels and do a test (if you've got a hydrometer?). Failing that try to get the battery off and take it to your local auto-electrical place and ask them to put a test on it for you. Please remember to leave the key in the ignition with the ignition turned on before you try to remove the battery - follow the link that Richard put up on this thread earlier. Here it is: http://www.porscheclubgbforum.com/tm.asp?m=331718 It's quite possible that your car has been sat around with this duff battery for some time and that the OPC just kept it on a battery conditioner to stop the alarm going off. If just one of the cells has gone then the battery is knackered - despite the fact that there are five others to keep things running! All the best. Adrian.

Thanks- thats most useful! The current battery was only installed (new) last year, 6k miles ago so hopefully ought to be OK. The danger is that it has become terminally low at some point, damaging a cell. I'll try with jumpers later, but may need to get back to the dealer for a replacement battery Thanks for the info on battery removal (but I can't access it as I'm not (yet) a member of PCGB)! Think I saw another link somewhere!

No problem, Neil. The salient point in the link that you can't access is to make sure that you leave the ignition turned on before you try to loosen either of the terminals on the battery. When you've got the battery off leave the key where it is too! If you don't do this the alarm will go off and you'll feel like George Foreman in round eight and your neighbours will be striking you off their Christmas card lists! (Trust me, I had to learn the hard way on this one!) Adrian.

Noted and understood!

OK- seems to be sorted now (I hope!) When I got home I tested the voltage and it was down to 8.5V. Tried it on a charger for a couple of hours (a not very good one admittedly) and it made little difference so connected to wife's car with jumpers. Initially still nothing, but after about 5 minutes letting it top up it started. All displays and settings preserved OK. Have now driven it about 100 miles over the last 2 days and it has started 1st time each time. Voltage with engine off showing 12V and running showing 14.2V. Dealer has been helpful- offered to pick it up or come over with a new battery if the problem recurs, so I'll see what happens in the next few days. Thanks again for the help!

Ok Neil, glad you're sorted. 14.2 volts does sound like your battery is calling for more charge from your alternator - the usual reading is around 13.7 volts at tick over. It's probably just because the battery isn't quite back to where it should be yet. It probably just needs a really good long slow charge. All the best. Adrian.

Sounds like I need to invest in a decent charger then! Car will normally be used every day for around 12k miles per year, otherwise I'd get a conditioner. I'll see if normal driving gets it topped up over the next week. Hadn't crossed my mind that the higher charging voltage could be due to increased demand!

I've had the bosch silver in my car 80ah. It lasted for 2 years but as i recently have had problems starting the car i took it back to eurocarparts and they simply changed it for another new one at no cost. They didn't even test it....must be my honest look!!!! Good job they have changed it without cost cause i'm now fitting a new alternator as i believe this to be the problem. I suppose if one goes, the other is also at risk. Got the old alternator off. Thinking oof purchasing an alternator from rotating electrix as it seems to be half the price £120 as opposed to £280. Anyone used these before???

Haven't used that firm but I had to get a new alternator at 14K miles [:'(] and I got my indi to get me an equivalent one to the Porsche one - but without the Porsche sticker. I think it was around £160 as opposed to something like £300. Unbelievable! I've since learnt that I might have been able to just replace one part of the alternator instead of the whole thing...? Not sure what the part is called though...? You should have seen the 'old' alternator when it came off the car; it was like a new one out of the box!! [ ] What a shame!

After much sole searching on the internet i was gobsmacked to find a local alternator repair company. Cost me £133 including vat, done in less than 3 hours turn around. with 12 months warranty all i need to do now is re fit and get the car back on the road. yippee!!!

Resurrecting an old topic here, but my battery problems appear to be present still! Since my last report, all has been well, but the charge rate has stayed at just above 14V most of the time. Yesterday, I needed to have the A/C regassed so took it to KwikFit. At the end of the process (just over 1hr) they tried to start the car, and it failed, with the alarm blaring in the workshop! Luckily a jump lead was handy and it started. I asked if it had been left with anything switched on during the regas but apparently only the door/bonnet was left open, so the courtesy lights were on. They put the battery on their Bosch tester; itr came up as the alternator fine, but the battery 'unservicable'. Their advice was to take it to an electrical specialist to trace whether the fault was the battery itself or a related circuit. The A/C is now fine and the 'grinding noise' gone, so £49 well spent there! As for batteries, I've heard good things about Shield batteries which are made in Bishops Stortford, which is 4 miles from me; they have a sales counter. Their 'heavy duty' model for the 911 is rated at 75AHr which is a little lower than the one fitted. Would this be within tolerance? Price is good at £68 +VAT cash and carry, fully charged. The symptoms all point to a dodgy battery, so I'm tempted to just change it without going in for further testing!

Hi Neil. So this is still the original battery that was giving you trouble - or did you change it for a new one? If it is the same one then it sounds like it's had its day. But it does seem odd that it has been giving out a good voltage and then just failed. I'm no electrical expert but it could be that there is what someone once referred to me as sedimentation on the bottom of the battery. This could be effectively shorting the plates out and you're then loosing all of your charge. This was more prevalent is acid batteries rather than the newer gel ones, I think. It sounds like you might be on to something with Shield. There'll almost certainly be someone there who would be able to tell you what's happened. Adrian.

Yes- it is the same one. Although apparently only fitted in 2009 by an OPC, it is a 'no-name' battery. I strongly suspect sitting in the showroom for a while may have knackered it! It seems OK until it is put under some sustained load, then it just dies quickly. I suspect a dodgy cell somewhere, or as you say something amiss inside. I've decided to replace it anyway- but changed my plan and now gone for a 100AHr Varta for £100.

100 Ahr !!! That'll turn a Veyron over! (Don't tell me: a Veyron takes two 100 Ahr batteries!)[ ]

HeHe- that's one I'll never get to try (and can't say I'd particularly want to!) Yes- interesting that the Advanced Batteries website specifies a bigger battery for the C4 than other models, and the battery fixing plate certainly has a hole to move it out to the wider fitting (350mm)