Re: Parking lights - how long should the battery last?

[Jack Bunce <jackbunce@xxxxxxxxx>]

On 2/3/06, Cees De Groot <cdegroot@xxxxxxxxx> wrote:
> ... It was cold-ish,
> around freezing point, and I left the bike for around 8 hours.
>
> Is it a signal that I have to start thinking about a new battery (I
> guess that this is the original one from '99) or should I just be more
> careful?

What is the nominal stated capacity of your battery in amp-hours?

>From the long distant past I recall that battery ratings used to be at
the ten hour rate at a warm temperature, e.g., a 20 AH rated battery
would supply 2A for 10 hours at 65 F before going flat.  If the draw
went to 10 A it would go flat well before the 2 hour mark.

What is the wattage of your parking light bulbs? On my R1100S the
parking lite bulb is 5W.  If the parking light switch position also
causes the rear light to illuminate that is an additional 5W for a
total of 10W.  At 12.5 v that is a current draw of about 0.8 amp over
8 hours that is approximately 7 amp-hours or about half the battery
capacity of my R1100S when new and warm.

That would leave about half the battery capacity left to start the
bike (on a warm day).  Your day was cold and your battery is not new.

Have your battery load tested.

- --
cheers... jack

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