Charon
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I don't know that I can answer whatever the original question was, but I can provide a little information. You may take it for whatever you feel it is worth.
My motorcycle is an '07 S40, which I bought new in August '06. I do not know the date code on the battery, but imagine it to be the first half of '06. The bike was already dealer-prepped when I bought it, so I cannot vouch for whatever prep the battery received. I had ridden the bike about fifty miles on Oct 16 and parked it in the garage.
Yesterday, Oct 26, I made the following measurements. Battery voltage, 12.37, using a Fluke Model 11 Digital MultiMeter (DMM). There being (just) enough room for my EXTECH AC/DC Clamp Meter, I clamped it around the positive battery cable. Turning on the ignition switch showed 6.9 amps of current, powering the headlight, taillight, running lights, and ignition module. I turned off the switch, removed the clamp meter, reconnected the voltmeter, and turned the switch on again. Measuring the battery voltage with the switch ON showed 11.77 volts (which implies an internal battery resistance of 0.087 ohms). I removed the DMM and reconnected the clamp meter. When I started the engine, the clampmeter very briefly showed 83 amps. Briefly, both because of the sampling and display time of the meter, and because the engine started on about the third time through compression. On engine start (on full enrichener) the clampmeter showed a charge current of about 6 amps, which fairly quickly dropped off. As I pushed the enrichener in the engine rpm dropped and so did the charge current. When the engine was running steadily at idle the meter showed about 1.5 amps of charge, and revving the engine (maybe 2000 - with no tach, who knows?) didn't increase it to much over 2 amps. Leaving the engine running after the charge current stabilized, I removed the clampmeter and rechecked the battery voltage, which was 14.96 with the engine idling. Revving the engine slightly raised the voltage to 15.00.
This whole procedure took less than ten minutes. I shut off the bike, put on suitable attire, and went for a ride. When I got home I parked the bike, and an hour or so later checked the battery voltage, which showed 12.80. I rechecked it this morning, after it sat overnight, and it was 12.66.
The initial charge current of about 6 amps, plus the original current demanded by the lights and ignition, imply that the alternator is capable of sourcing at least 13 amps. The terminal voltage of 15 volts once the charge current stabilized is higher than any normal float charger, and would completely charge pretty much any lead-acid battery given some time.
The usual drill for automotive charging systems is to attempt to maintain the battery at full charge. They do this by supplying a voltage-limited charge current (that's why it is called a "voltage regulator"). The idea is to replenish the battery as quickly as possible, against the possibility of short trips and frequent starts.
Did that add to the confusion?
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