Battery Problem?

67Rob · Mar 22, 2015

Parked the RR up on Thursday night and yesterday afternoon it wouldn't start, had just about enough power to turn slowly but not fire up.

Jump started it this morning and all seems ok at the moment.

What would cause the battery to drain over 36 hours?

gencybay · Mar 22, 2015

67Rob said:
Parked the RR up on Thursday night and yesterday afternoon it wouldn't start, had just about enough power to turn slowly but not fire up.

Jump started it this morning and all seems ok at the moment.

What would cause the battery to drain over 36 hours?

Wammers' and Datatek's blood vessels bursting simultaneously.

More helpfully (hopefully), these are prone to radio interference that keeps the security system waking up. The proper fix is to replace to RF unit just under the rear r/h window.

I think Datatek knows of another fix using another RF system to disconnect the RF receiver when you leave the car.

G~

zzr1200 · Mar 22, 2015

Agree.

RF Unit probably, also possible battery output/size problem if its a diesel???

67Rob · Mar 22, 2015

gencybay said:
Wammers' and Datatek's blood vessels bursting simultaneously.

More helpfully (hopefully), these are prone to radio interference that keeps the security system waking up. The proper fix is to replace to RF unit just under the rear r/h window.

I think Datatek knows of another fix using another RF system to disconnect the RF receiver when you leave the car.

G~

Thanks, hopefully this is an easy fix.

67Rob · Mar 22, 2015

zzr1200 said:
Agree.

RF Unit probably, also possible battery output/size problem if its a diesel???

It's a petrol. I'm going to replace the battery anyway as it looks like a Halfrauds type.

quavey · Mar 22, 2015

Whats the condition of the battery? And size? State of Alternator?

I had a similar problem on mine when it had a duff battery, it steadily got worse down to the stage where it would only last 5 days or so. I then bought a new battery, big 130ah job and it was not really any better. After going around the houses looking for a drain I couldn't find anything and it began to get to the stage where it wouldn't last 12 hours and lived on a continuous trickle charger.

I managed to get the battery tested and it was declared faulty.. I sent it back and got a replacement and it will now last more than 2 weeks (the longest I've left it between use). So even a new battery can be faulty!

dogsbody · Mar 22, 2015

The RF unit is the prime culprit, it can be affected by many modern radio devices, even as simple as a wireless doorbell and it then can cycle the door locks or just keep the BECM awake.
However, if you've got headlamp wipers, it has been reported that one of these not parking correctly can drain a battery. Worth a quick look.

67Rob · Mar 22, 2015

quavey said:
Whats the condition of the battery? And size? State of Alternator?

I had a similar problem on mine when it had a duff battery, it steadily got worse down to the stage where it would only last 5 days or so. I then bought a new battery, big 130ah job and it was not really any better. After going around the houses looking for a drain I couldn't find anything and it began to get to the stage where it wouldn't last 12 hours and lived on a continuous trickle charger.

I managed to get the battery tested and it was declared faulty.. I sent it back and got a replacement and it will now last more than 2 weeks (the longest I've left it between use). So even a new battery can be faulty!

Alternator fine and battery condition good.

dogsbody said:
The RF unit is the prime culprit, it can be affected by many modern radio devices, even as simple as a wireless doorbell and it then can cycle the door locks or just keep the BECM awake.
However, if you've got headlamp wipers, it has been reported that one of these not parking correctly can drain a battery. Worth a quick look.

Just checked and the driver's side headlamp wiper was parked slightly up.
Have now moved it down but it seemed to feel parked.

In the pic it's how it was parked.

67Rob · Mar 22, 2015

Just went to start it and the battery is now as flat as a witches' tit.

Have my tech friend checking it as I type this and he reckons the battery has just decided to pop its clogs, so I'll buy the right one tomorrow and replace the Halfrauds copy that the previous owner put in.

wammers · Mar 22, 2015

67Rob said:
Just went to start it and the battery is now as flat as a witches' tit.

Have my tech friend checking it as I type this and he reckons the battery has just decided to pop its clogs, so I'll buy the right one tomorrow and replace the Halfrauds copy that the previous owner put in.

If it's a Gel battery they go over a cliff from which there is no return, can happen in a matter of minutes. Ok one minute totally goosed the next.

67Rob · Mar 22, 2015

wammers said:
If it's a Gel battery they go over a cliff from which there is no return, can happen in a matter of minutes. Ok one minute totally goosed the next.

Don't know if it's a gel battery but it's knacked. The alternator is pushing out 13.8 volts so at least it's not that.

Datatek · Mar 22, 2015

Battery Megastore on line 1000CCA 130AH, the biggest battery that will fit, about £98 delivered.
13.8 volts is low, you should have 14.2 volts (or more) at 2K rpm to charge a modern battery.
However, some P38's have 13.8 volt alternators fitted.

67Rob · Mar 22, 2015

Datatek said:
Battery Megastore on line 1000CCA 130AH, the biggest battery that will fit, about £98 delivered.
13.8 volts is low, you should have 14.2 volts (or more) at 2K rpm to charge a modern battery.
However, some P38's have 13.8 volt alternators fitted.

Cheers for that info.

Grrrrrr · Mar 22, 2015

Older bottom range cars only kick out 13.8V from the alternator. Mine does and struggles to charge a CCA battery on short journeys in the winter.

wammers · Mar 22, 2015

67Rob said:
Don't know if it's a gel battery but it's knacked. The alternator is pushing out 13.8 volts so at least it's not that.

13.8 is minimal for modern batteries. You need 14.2 for low maintenance low antimony batteries and a minimum 14.4 and up to 14.8 for full calcium. You can get a 14.2 controller for less than £20.00, worth considering.

brianp38dse · Mar 22, 2015

Rf reciver fix that was sergested http://www.landyzone.co.uk/lz/f10/rf-reciever-work-round-258096.html cheep and easy and rules out rf as battery drain.

67Rob · Mar 23, 2015

Thanks for all the advice. But the great/annoying thing is that it started first turn of the key this morning. Very weird.

grumpy52 · Mar 23, 2015

my son accidently put the interior light on in thr rear went flat over 24 hrs usually stands all week recharged all ok now

67Rob · Mar 23, 2015

Datatek said:
Battery Megastore on line 1000CCA 130AH, the biggest battery that will fit, about £98 delivered.
13.8 volts is low, you should have 14.2 volts (or more) at 2K rpm to charge a modern battery.
However, some P38's have 13.8 volt alternators fitted.

Having a bit of trouble sourcing this battery, I've tried most online places inc Fleabay.
Any ideas?

Datatek · Mar 23, 2015

67Rob said:
Having a bit of trouble sourcing this battery, I've tried most online places inc Fleabay.
Any ideas?

www.[B]batterymegastore[/B].co.uk The brand was Alphaline but that may have changed.

Battery Problem?

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