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1980 Rolls has new battery, but, if left sitting for 2 days, it dies. No lights, beeps, etc. and of course will not start. What might be draining the battery?

 

[Mark out West]

Next time you park it, disconnect the ground terminal from the battery. After a few days, if it's discharged, then suspect internal damage such as shorted cells. I've gone through several brand new batteries that were DOA from the store. Chalk it up to infant mortality.

If the battery retains its charge, then something onboard is drawing current even with the ignition off. Fairly easy to check with an volt-ohmeter. Identifying the circuit becomes an exercise in fuse pulling to isolate the cause.

 

[guyslp]

The last piece of advice was spot on. One thing to check first after you've determined you don't have a defective battery is the circuit that the clock is on. I've heard stories about clocks in these cars draining the batteries quite rapidly.

 

[ro80rob]

Since you say it is a new battery, we could perhaps assume its good.

You can do the tests others suggest by throwing the isolator switch in the boot (I'm assuming your car has one, my 89 Turbo R does and I guess that came from earlier models). Otherwise, disconnecting a battery terminal is for you to do.

Discharging the battery via the clock over 2 days is a fair amount of load, but I am not discounting that.

What I would be most concerned about is that there is a fault within the alternator rectifier (diode pack), which is always 'in circuit' to the battery. If this goes faulty, it will quite easily produce the effect you observe. Maybe you could get the alternator checked out also.

Cheers... Rob.

 

[CarDoctorDave]

Check the trunk light switch, they are known to break and cause the trunck light to stay on. It is located near the L/S trunk hinge

 

[rollmech]

are you sure all door lights go off on early spirits / spur which i assume this is as its a 1980 model the door switches had 2 switches. 1 switch did the internal interior ligts on the delay the other did the red warning light on the door and the puddle lights on the trim in the arm rest these weren't on a delay. Early switches did give problems

 

[Rodd Sala]

Another common problem to check is the central locking on (1980 - I am assuming it is a Shadow/Wraith II). Sometimes when a central locking solenoid is sticking, it is still drawing power and will quickly flatten a battery. If all your central locking is working fine then you can discount this as a potential problem.

Rodd Sala - Park-Ward Motors

http://park-ward-motors.com/

 

[jeyjey]

My glovebox light switch came adrift, which left the glovebox light on all the time. I'd imagine that would take longer than 2 days to drain a battery though - and I don't know if the mechanics of the glovebox light are the same on your car or not (mine's the earlier SSII/T2.)

Jeff.

 

[bentleyman22]

If you have that much of a drain I would go for the alternator
Have a look when it is dark and see if you have a glow from the battery lamp
Of just get the alternator checked

 

[ghosthunter]

Sadly, Shadow II do not have isolation switches. I had my interior courtesy lamps stay on for much longer than the Seven seconds because of a blown capacitor on the circuit board causing a flat battery, I replaced the blown 'Cap' with a similar type but of different capacity and it cured the fault and actually enabled the interior lights to stay on longer, which was a nice touch.

Another issue with a new battery proclaiming on the label to have a Four Year warranty, was the CCA rating was a little too low and this battery after just over Two Years went flat and I had to jump start my own car before going anywhere!

I have only just replaced it with a higher rating and won't know for a number of Years if this will take the battery up to the Four Year plus period of acceptable service.

GHOSTHUNTER.

 

[dewatson]

I have a similar problem with my battery draining. I would, however, like to fit the best quality longest lasting battery available. I have seen several quality batteries, with above average amperage, but all too big to fit into the recess in the boot. Can anyone recommend the best battery that will fit a 1987 Turbo R?

 

[guyslp]

I have a similar problem with my battery draining. I would, however, like to fit the best quality longest lasting battery available. I have seen several quality batteries, with above average amperage, but all too big to fit into the recess in the boot. Can anyone recommend the best battery that will fit a 1987 Turbo R?

Good luck with a "best" recommendation since opinions on batteries are often as vehement as those on oil or coolants.

That being said, group 27 size batteries are used in Rolls-Royce and Bentleys from 1946 to 1980 (and even later, I think, but I haven't checked for how long past 1980 - I believe the SZ cars still use them). Usually the positive post is toward the front of the car which would mean a 27F for cars with the battery on the right side [Clouds] of the car and a 27 for cars with the battery on the left side of the car [most, but not all, Shadows and Corniches]. Check the battery in your car before ordering a new one.

Any retailer of automotive batteries could take a look at the battery in your car (assuming it's the right size) and tell you the group size.

I have asked on the Australian forums whether the group 27 battery continued through the SZ cars and whether it was for the whole SZ era or if things changed during production.