Possibly dead battery???

[davidcross]

Left car week and a half and not enough charge to start car. I'm assuming it's the battery but when I bought the car 6 months ago I was told there was a 'new' battery been put on is the only reason i'm asking if it cud be something else......

 

[clubsport]

When you say not enough charge to start the car.....starting and turning over may be different problems..

When you turn the key, does the engine turn on the starter?

is there a clicking sound with no turning?

Does nothing happen when you turn the key?

Could be dead/low battery, could be dme relay, immobiliser or fuel/ignition probs...

A little more info may help with a response to the problem....

 

[davidcross]

Cars not turning over as there isn't enough power to get her up to start. Ignition lights etc on although pretty dull. Starter sounds slow when the ignition is switched on. I've got it on charge now so will give it s Try shortly
tks for reply

 

[A Ward]

A little known problem with the 993 is the earth lead/cable - my brother had exactly the same problem with his 993 (1997 P-reg)...he tried changing the battery, etc...and in the end resorted to keeping it constantly connected to the trickle charger.

In the end though we finally found out that the main earth cable was the cause - the cable looked absoultely mint but when you checked across it with a multimeter it was extremely high resistance/open circuit.

For the sake of 2 minutes with a mulitmeter - check across this cable to see if it is ok (should have extremely low resistance - approx 0 - 10 ohms)

Hope that helps as it is not a commonly checked item - particularly given that it can appear to be in perfect condition (as my brothers was) so would easily get ignored on outward appearance.

We proved it by removing the old earth cable and then 'slaving' in a jump lead to prove it was the cause of the fault.

 

[clubsport]

At least the starter is attempting to turn, so it sounds like you need a good charge as you said.

AWard, when you say earth lead, are you talking about the one to the battery...or the earth lead from the engine/gearbox?

I have had problems in the past with the transmission to bodyshell earth in the past as it is open to the elements.

 

[davidcross]

Huge help as always many tks. I left the car for a week in April and all was fine so was a little suprised by this, anyway just managed to fire her up after 2hrs on the trickle charger. I don't think the battery is new as was previously stated though. More, 'reconditioned' if that's possible!!

 

[davidcross]

I'll leave it on over nite. Shud b fine by the morning but I'll dissconnect it and leave it for the day and see if it holds a charge. Wud it be knackered battery if it fails to hold charge??

 

[clubsport]

I would concur, knackered battery if it fails to hold a charge...

I have been checking recently, as far as I can see, eurocarparts seem to have the best deal on Bosch silverline batteries for 993 C2, unless you have a Costco or other wholesale option.

 

[davidcross]

Actually I do have a costco card good point. On further investigation last nite I thought the battery doesn't look only 6 months old. I'll give her a run out today as well tks.

 

[A Ward]

Sorry the earth lead in question on the occasion we had problems was the main one to the battery - the car had been struggling to start for ages, alarm kept going funny due to low batttery, etc.. The cable itself looked as though it could have been fitted new from the packet the week before - it was only when tested with a multimeter that you could see it was quite clearly not right!

Fault was caused by the earth cable as mentioned in my earlier post - didn't matter how new the batttery was or how much you charged it - within a day it was struggling...sometimes sooner (nearly got stranded in Marlborough high street one time).

It may not be this - but it is such an easy thing to check...and far cheaper than a new battery to test. If you do buy a battery I would perhaps suggest trying to get one from Halfords as they do a 5 year guarantee on their batteries.

 

[Porker993]

Once the battery fails to hold a charge, it will keep on letting you down at the most inconvenient times and needs replacing. A good battery should last four years or more.

Bosch silverline is highly recommended. Needs to be 75 amps or more, according to the handbook. Anything less is not man enough for the job.

You could do some detective work on your old battery - how many amps, date of manufacture, maker etc. This will tell you whether your vendor was telling porkies.

For peace of mind I would replace it pronto. It's a small outlay for a vital part.

 

[clubsport]

Porker993,

You mention the requirement for an 80 amp or more output according to the handbook

I assume this is an AH metric.

Does anyone use a battery this powerful.

I currently have a 72AH Bosch Silverline on mine.

Most of the batteries available in Type 096 for the 911 seem to be in the 70-72AH, range with the off one at 74AH and one I noticed at 77AH.

So, what output batteries are people running, 80AH as per the handbook?

or lower?

 

[Porker993]

Porsche workshop manual actually states 75 Ah, so I guess your OK with 72. Don't know where I go 80 from, but I distinctly remember seeing it somewhere. Must be getting old. Can't do any harm though.

 

[clubsport]

So what AH battery do you run porker?

Anyone else??

From apparent availability I will be surprised if many are running 75AH or more.

 

[Porker993]

I've changed my original post to say 75Ah. My latest battery is 72, but it was a bit of a kwik fit cheapo I bought in an emergency when my alternator packed in. I will be moving to Bosch next time round.

On these cold mornings there is a hint of reluctance to crank, so I will probably need to follow my own advice before long.

 

[davidcross]

sorry id forgotten to follow up the conclusion to my original post.
I had the car alarm go off at 6am last friday morning as the battery had completely died after being left for 24hrs after a full charge. I took the battery to a local Motor spares place to be check who confirmed it had dead cells. After fitting the new battery (72amp and £90) i ran it back to them for an Alternator check which was confirmed to be ok. In fairness they did a good job without ripping me off for the battery or trying to sting me for a new alternator. Car runs a dream again and no lack of starting power with the 72amp

 

[Porker993]

David glad to hear all is well. The consensus seems to be 72 Ah is fine.

PS. it's the CCA (Cold Cranking Amps) figure that affects cold starting. This is usually around 660 (must check that out for the 993)

Also, what make of battery did you fit ?