I was dispatched to the local chippy last night and, returning to The Princess through driving rain and howling wind, jumped in, ignition on and turned the key to start, only to be met with no cranking sound at all and a stream of fault messages on the display. Park brake fail, gearbox fault, DSC fault, cruise control fail, you name it...
Looking at the weather, and the fact that SWMBO was waiting for her supper I sort of swallowed hard and re-cycled the ignition switch only to see the same again except not quite as many faults. Eventually, after recycling the ignition seven times, she smoothly burst into life.
There was clearly ample capacity in the battery to turn over the engine very rapidly.
I drove home without incident but, having parked in the garage, I switched off, waited for a few seconds and tried to re-start, seeing the whole problem again. Now, bearing in mind that there had been more than enough battery power to spin the engine over, I was less than confident that the fault originated in the S-Type's notorious sensitivity to battery voltage.
Anyway, I connected up the battery charger, one of those new fangled digital devices which you can use on the more modern batteries and it did a quick check on the battery informing me that it was at 60% capacity. According to the charger manual that indicated a no load battery voltage of 12.1 volts. It then proceeded to run an automatic charge and test sequence, culminating in a reading of 100% when i looked at it this morning.
Sure enough, The Princess started smartly, first time, and with no fault indications.
Now, on reflection, all I had done was move the car around on the drive a few times yesterday, say eight start / stops, without allowing the engine to recharge the battery. In addition, the battery is only a few months old and the battery charger pronounced it perfectly healthy.
Clearly, the S-Type is extremely twitchy when it comes to battery voltage.
I don't care thoguh. I still love the darned car to bits