s.2 won't jump start

[Anatol]

I'm getting 13-14 volts across the terminals of the exige's battery with a jump, but all I'm getting when I turn the key is repeated clicking, and then a buzz/vibrate (with a shudder at the speedo needle) when I switch the key off...

What's this likely to be?

Tol

[kambites]

Have you checked the voltage across the battery terminals while you are trying to start the car?

[Vlad.]

Battery knackered? Happened to my Elise when I left it off the trickle charger for 3 weeks. Seemed to have voltage but wouldn't charge properly and I had symptoms similar to yours when I did try to start. Replaced battery and all was ok.

[Anatol]

voltage at the front clam terminals drops to almost exactly 12v when the ignition key is turned to position 3. I'm on my own, so can't position the multimeter at the battery itself and read it/turn key simultaneously...

Tol

[Anatol]

Vlad. said:

Battery knackered? Happened to my Elise when I left it off the trickle charger for 3 weeks. Seemed to have voltage but wouldn't charge properly and I had symptoms similar to yours when I did try to start. Replaced battery and all was ok.

Even with a jump start? *boggle*

Tol

[kambites]

I suspect the car you're jumping from can't, for whatever reason, supply enough current to drive your starter motor. Do you have the engine of the car you're jumping from running?

[tanman]

Sounds like it maybe the alternator- If you've got that much voltage across the terminals that would be my guess.

[Anatol]

kambites said:

I suspect the car you're jumping from can't, for whatever reason, supply enough current to drive your starter motor. Do you have the engine of the car you're jumping from running?

Yes, donor car is running - and it's an XKR with a hoofing great battery, so I doubt that's the problem...

Tol

[kambites]

tanman said:

Sounds like it maybe the alternator- If you've got that much voltage across the terminals that would be my guess.

14 Volts is about right.

[kambites]

Anatol said:

kambites said:

I suspect the car you're jumping from can't, for whatever reason, supply enough current to drive your starter motor. Do you have the engine of the car you're jumping from running?

Yes, donor car is running - and it's an XKR with a hoofing great battery, so I doubt that's the problem...

Tol

Some cars are very bad for jump starting from, for some reason. My lodger's 3-series couldn't be used to jump start anything, I have no idea why but it just wouldn't supply enough current.

[Anatol]

Hmm. I've jump-started vans off the Jag before, but I don't pretend to understand all the complexities... sounds like a phone call to the RAC later on today...

[Vlad.]

Anatol said:

Vlad. said:

Battery knackered? Happened to my Elise when I left it off the trickle charger for 3 weeks. Seemed to have voltage but wouldn't charge properly and I had symptoms similar to yours when I did try to start. Replaced battery and all was ok.

Even with a jump start? *boggle*

Tol

Sorry, didn't read your op properly.

[wezzer-45's]

For some reason Elise's end Exige's don't like being jump started.
It doesn't matter if you are using a booster, battery or a running car, they are still reluctant to start. Just get the solenoid clicking.
Either recharge the battery or put another battery on the car.
You can try and leave the jump leads connected for 15 mins or so, this will put some voltage into the flat battery and sometimes the car will then start.

[kambites]

I managed to jump start a friend's S1 from my S2 with no problems (well, except getting the jump leads to the battery). Haven't tried jump starting mine yet - I tend to trickle charge it if I go away for long.

[Demolitionman13]

Anatol said:

I'm getting 13-14 volts across the terminals of the exige's battery with a jump, but all I'm getting when I turn the key is repeated clicking, and then a buzz/vibrate (with a shudder at the speedo needle) when I switch the key off...

What's this likely to be?

Tol

Tol, I had exactly the same symptoms yesterday...managed to bump start the car, but multimeter was telling me that the battery was below 12v. Went to Halfrauds with my trade card and purchased a new battery. Installed and all is sweet again.