charging battery problem!

[RUFFO]

hi guys, i just brought a CBR 600 RR mod 2003 and the thing is that when i started its ok, but after a 20 minutes of use in road, i turn off the bike and then i try to start up again and the battery is low , at least sound like that, then i wait until the bike is cold and then the battery is ok and i can start up my bike.
i change the battery, but the new one do the same.

after that, i call to the honda service, and they tellme that this kind of bike is to be a real runner and i sholud run it in high revolutions to keep the battery charged bicause in low revolutions the battery is in use bicause there are so many light on by default.
and yes, usually im easy bike driver, so they recomend me to unpplug the head light that is on by default, and they say that way the battery will be better charged.
the question is..... is that right what the honda service toll me?
or i got some problems with the altenador or something else?
i have been checking the charge that the battery recive from the alternador, and when the bike is cold, the charge is 14 volts, when is warm the charge is 13 volts, but when te fan is on, the charge battey got 12.5 volts.

thanks for read me and i will apreciate any information.

[mydlyfkryzis]

i have been checking the charge that the battery recive from the alternador, and when the bike is cold, the charge is 14 volts, when is warm the charge is 13 volts, but when te fan is on, the charge battey got 12.5 volts.

thanks for read me and i will apreciate any information.

At what RPM are the voltage readings from? Your alternator will not charge the battery at low RPM. If your bike redlines around 14000 RPM, I doubt you have full alternator charging until 5000-6000 RPM or slightly higher.

Get a manual and see what it is supposed to be.

[kyle.H.]

if u just bought it from a trade place then just bring it back and ask full a electrical test, they hook it up to a big computer and run on a running machine type thing its cool, i happened to my cb

[RUFFO]

the reading voltage is at 1200 RPM, the more i rinse the RPM the more voltage is getting from the alternador intil 14.3 voltage

[Pongo]

so they recomend me to unpplug the head light that is on by default, and they say that way the battery will be better charged.

Not good advice.