How much extra current is available on an '81 CB650C?

[entropy]

I know that the CB650s of this era have a reputation for anemic charge systems, but I'm wondering if anyone has tested just how anemic. I'd like to steal almost exactly one amp (worst-case), i.e. about 12-14 W, to charge my amateur radio handheld in the tank bag while on a long upcoming trip.

Normally I'd just rig up the system and see, but I'd have to order parts to perform the test: either the car charger for the radio or some other combination of large resistors (I can't make anything near 10-12 ohms with the power resistors I have). I'd prefer not to spend any money on this if someone already knows the answer...

The service manual isn't terribly helpful in any of this, giving only same guaranteed minimum generator output, etc. The motorcycle has no indicating of charging problems and has never had an issue keeping the battery charged. I've no idea if the PO ever had to replace the rotor or R/R.

EDIT: okay apparently this motorcycle runs a 40/50 headlight bulb, so my earlier assumption about this clearly working when the high beam is off isn't quite so clear. 10 W more consumption on high beams means there's likely overhead if the high beam is OFF, but what about when it is on? (If push comes to shove, I can always rig the charger input to turn off when the high beam turns on, or even install an HID kit to maybe cut the total headlight consumption, but I'd prefer to avoid that hassle/cost if possible, too.)

Thanks in advance for any information / advice / wishes of good luck!

[MiGhost]

If you switch over to LED lights in the gauge cluster, and indicator panel you will save enough to run the charger.

Ghost

[entropy]

Hmm. Good idea. 50 mW LED lamp versus a 2 to 3 W lamp, times a few of them...

Any idea where I might find a list of the bulb sizes used behind the indicator panel and inside the gauges?

[MiGhost]

Here is good discussion on LED lights
viewtopic.php?f=3&t=3649

The indicator/dash lights will be BA-9

Ghost