On Tue, 24 Mar 2020 14:12:20 +0000, charles wrote:

In article ,
Dave Plowman (News) wrote:
In article ,
Graham Harrison wrote:
The battery on my car gave up last week. I'm used to the idea that
when the battery is dying things like lights get weak and the car
gets difficult to start.

Not this one.

The first clue (which I missed) was that the radio failed. Car was
due for a service soonish so I just put up with it. Except that one
day, driving along, the radio came on of it's own accord but didn't
work. Then the glowplug light stayed on after the car was running.
Finally it failed to start but the lights still worked.

I was still not tuned to the idea that the battery had failed.

When I had the battery replaced I asked a few questions about why I'd
missed the clues. I was told that modern cars "load shed" so when the
battery starts to play up unimportant things (like the radio) are
deemed not worthy of needing power and are "disconnected".

I've learned something!

Odd - given modern alternators can cope with the total load at very low
engine speeds.

My C5 (replaced 7 years ago) did some form of load shedding if the
battery wss getting flat. Parked up for a week and the remote unlocking
didn't. The was a relevant message on the car's display screen.

My S-Max does this. There are peiods when I only do short journeys, then
I go back to longer ones.

After a period of short journeys, the touch locking ceases to work on all
but the driver's door. Sometimes that goes out too and I have to press
the button on the fob.

Not got as far as the emergency key yet.



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