Battery Low Warning

[AlanD]

Hi all,

Those who follow the Mondeo sub group will know I replaced the battery in the MA a few months ago.

Today while waiting for the GLW, who was getting some diagnostic tests done at Monash, and playing the radio with the keys out of the ignition, I got a "Low Battery" warning in the information display.

"Curses" I thought, "Just my luck to get a dud as a replacement"

But some tests when we got home indicated something was amiss. The battery was showing 11.75 volts with no charging, but 12.8V or so when being charged, which is insufficient to get a Lead Acid Battery to full charge. So I began to wonder about a faulty charging system. Got The GLW to start the car to check on the terminal voltage under maximum load and noticed some sparking in the region of the main body 0 Volts connection. (It's a bolt with an odd head shape adjacent to the battery shroud on the RHS as you look from the car's front).

Then I remembered that when the battery was being replaced the "guy" tried to undo this connection and I stopped him, pointing out that to do so would defeat the attachment of the backup battery. But a quick check showed that he had managed to loosen it slightly and it did not get tightened up, creating a higher than normal resistance through the join.

Application of a 13 mm spanner seems to have solved the problem. The charging system is now applying 14.1 to 14.2 volts to the battery and off load the battery is holding 12.8 volts. I'll keep an eye on things and report if the "fix" is a permanant one.

While this was going on I also noticed the headlamps flickering at idle and wondered why this was happening, as I had not noticed it previously. My guess is that under running conditions the vibration changed the connection resistance enough to cause this effect - I'll keep an eys on that as well.

Moral is - Pays to check electrical connections and make sure they are sound.

Cheers