V8 vantage battery issue

[scotpak]

Hi Guys

So its 5.30pm, looking forward to starting my easter weekend, go to the my car in the staff car park, turn the key,
the starter button's light comes on. I press it, the car doesnt start and then all the electrics go dead!!!!

I drive the car daily on my short (8 mile commute) so surely the batteries not dead. Did I leave the lights on??? No.

Go back upstairs to call the RAC, then decide to just leave the car at work as Im on holiday for 2 weeks. BUT I need the stuff in the boot!!

The boot obviously does not open anymore as its electric, so I try to access it from inside the car. Lift the panel behind the seats to reveal
lots wires. Then suddenly there a few noises (sounds like the central locking). I go back and turn ignition, press starter button and car starts and all electrics
work. Boot still does not open, but I can go home!!! yes! Drive 8 miles, get home, boot opens and I manage to get my holiday stuff out.

Any idea whats going on here??? Is battery on its way out? Is there perhaps a loose connection which I may have moved when lifting panel behind seat?

Man, I hope this does not become one of those problem astons!!!!

Also, Im gonna be on Holiday for 2 weeks, Is there anything I can do to prevent battery from draining?

Thanks in advance!!

[drofnavi]

Check your battery terminals first, make sure neither are slack or corroded.

[Neil1300R]

Did you knock the Immobilizer button on the remote?

[v8woollie]

Neil1300R said:

Did you knock the Immobilizer button on the remote?

There's an immobiliser button on the remote?

[355f]

scotpak said:

Hi Guys

So its 5.30pm, looking forward to starting my easter weekend, go to the my car in the staff car park, turn the key,
the starter button's light comes on. I press it, the car doesnt start and then all the electrics go dead!!!!

I drive the car daily on my short (8 mile commute) so surely the batteries not dead. Did I leave the lights on??? No.

Go back upstairs to call the RAC, then decide to just leave the car at work as Im on holiday for 2 weeks. BUT I need the stuff in the boot!!

The boot obviously does not open anymore as its electric, so I try to access it from inside the car. Lift the panel behind the seats to reveal
lots wires. Then suddenly there a few noises (sounds like the central locking). I go back and turn ignition, press starter button and car starts and all electrics
work. Boot still does not open, but I can go home!!! yes! Drive 8 miles, get home, boot opens and I manage to get my holiday stuff out.

Any idea whats going on here??? Is battery on its way out? Is there perhaps a loose connection which I may have moved when lifting panel behind seat?

Man, I hope this does not become one of those problem astons!!!!

Also, Im gonna be on Holiday for 2 weeks, Is there anything I can do to prevent battery from draining?

Thanks in advance!!

Had this issue on my car and turned out to be the main power relay

[scotpak]

Thanks. Will check battery tomorrow morning.

Anyone think its something obvious or should i take it to dealer when i get back from hols?

[mikey k]

Not sure 8 miles commute is long enough to recharge a battery after cranking a cold engine with thick oil
What age roadster is it?
Original battery?

[Jockman]

Faulty earth ????

My understanding is that 35 miles is required for a full charge of the battery

[mikey k]

Jockman said:

Faulty earth ????

My understanding is that 35 miles is required for a full charge of the battery

Depends on type of journey low/no revs won't charge it so an urban commute is bad
Cold cranking takes more out and a cold battery doesn't work as well
That's how I killed a battery in the S within 3 months of it coming out the factory.

[Neil1300R]

v8woollie said:

Neil1300R said:

Did you knock the Immobilizer button on the remote?

There's an immobiliser button on the remote?

Press the "lock button. Car is immobilised.
Can see a scenario, where you are sat in the car, try to start it at the the same time knock the "lock" button. You will hear the car doors trying to lock - click - at the same time as you try to start it. Electronics get confused. Car immobilised.
May try it over the weekend just because!

Edited by Neil1300R on Thursday 28th March 22:09

[scotpak]

As discussed in my original post, the strange bit was when I lifted panel behind seat, and suddenly all the electrics came back on???

Surely if battery wasnt charged or last charge this would have happened?

I will check for loose connection tomorrow, otherwise it could be a haunted car???

[mikey k]

I asked about year as earlier ones had battery disconnects later ones do this at a certain voltage
My S did similar bizarre things when the battery was on its last legs

[scotpak]

Its an oct 2006 coupe

[scotpak]

ok, just checked car. Starts up fine, all electrics working, boot working etc

Checked the battery for any loose connections but nope. There is a bit of green discoloration on the battery connector
but apart from that everythings cool.

Have pressed the battery disconnection switch in the boot, and then will get it checked out when Im back from my hols in 2 weeks.
Its a 2006 car thus will probably change battery just to play safe???

[drofnavi]

The battery terminals need taken off and cleaned. The green stuff is corrosion and needs to be cleaned, as it's giving a bad connection.

[mikey k]

drofnavi said:

The battery terminals need taken off and cleaned. The green stuff is corrosion and needs to be cleaned, as it's giving a bad connection.

bit of grease on them after clean to help prevent it. That battery is 6.5 years old now though.

[drofnavi]

If that's the original battery, I would replace the battery as well. Modern batteries don't seem to last that long and ofter fail with little or no warning.

It is never convenient no matter when it fails. As a matter of course on my old cars I change the battery every 5 years or so. Much easier changed in the garage than on a weekend away or rushing to an appointment.

[355f]

scotpak said:

As discussed in my original post, the strange bit was when I lifted panel behind seat, and suddenly all the electrics came back on???

Surely if battery wasnt charged or last charge this would have happened?

I will check for loose connection tomorrow, otherwise it could be a haunted car???

As I meantoned in my original posts, your symptoms were exactly the same as mine- it was the main relay

[Lunablack]

mikey k said:

bit of grease on them after clean to help prevent it. That battery is 6.5 years old now though.

Petroleum jelly works well........

[drofnavi]

It might well be the power relay, but cleaning and tightening the battery terminals costs nothing. having the relay tested and if necessary repalced at the dealership will incurr a significant cost unless covered by a warranty.