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Another battery querstion

You can tell it's winter, can't you, with all the recent battery threads. Well, here's another.

Mini Cooper 2003.

I got home from a fast ~60 mile motorway run at 4.30 am this morning. Went out to about 10.30 and the battery was as flat as a pancake - not even a glimmer of any lights. Measured 0.5v.

Clock lost time but radio retained code.

Got a jump start and it started ok. Went for a run, tried switching off and restarting a few times while on the move and it restarted ok.

Voltage on battery terminals while idling ~13.6, rises to 13.8 on a fast idle. When switched off voltage ~12.7, drops to ~12.5 after a couple of min and stays there. Does not drop appreciably when headlights turned on.

Checked boot light, interior light not stuck on, ok.

Battery is about 3 months old, a Bosch Silver S002.

It's _possible_ I might have left the headlights on when I got home this morning, I was pretty groggy when I got home and just wanted to get to bed. Would that have been enough to totally flatten the battery in six hours (between 4.30am and 10.30am), or is my new battery f***ed?

Reply to
Mike Tomlinson
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Your battery is 54 amp hours so about 54 x 12 = 648 watts

Two 55 watt headlamps would flatten it in 648 / 110 = approx 6 hours.

Reply to
Dave Baker

In message , Dave Baker writes

My Mondeo switches off the headlights when I switch off the engine. I would think most modern cars do that?

Reply to
Gordon H

Anything with properly programmed multiplexed wiring should.

ISIS $1500 for a 3 module system seems way over the top as a retro fit. Actually useless as it doesn't seem to support "input" on the far end modules, just the master dash unit So it can't control the pass windows from a drivers door switch or the cabin light from the door switches without running wiring all the way back to the dash.

Reply to
Peter Hill

My old Rover SD1 does - long before multiplex wiring was thought of for cars. It has old fashioned relays for the headlights.

Reply to
Dave Plowman (News)

First car I came across that did it was a 1983 Ford Sierra.

Chris

Reply to
Chris Whelan

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