Some months ago I promised that I'd tinker and experiment with this weak link. I've now done so; here are the tinkerings and results:
1. The first and most significant improvement resulted from replacing the tail-light bulb with a LEDACE 25RST http://www.norbsa02.freeuk.com/goffyleds.htm -- riding with the light switch in the headlight position but with the dimmer switch centred (leaving either headlight available for navigating traffic queues / parked cars / overtaking) -- check out Paul's halogen bulbs too; he has direct replacements and good ident pics for Bosch, British pre-focus and US pre-focus, one of which should fit the standard Stanley beam units.
- Upside - i) this immediately 'saves' current consumption (amps) thus providing a lift in battery terminal voltage, ii) use of the rear brake doesn't tax the battery
Downside - i) the difference in light output between tail- and brake-light isn't as significant as the incandescent bulb (x2 as opposed to x3), ii) the white light for the numberplate/licence plate is a bit weedy
And after - @ 4000rpm, : 13.40V / 2.8A
2. The second improvement has been replacement of the old (but not original) 15A(?) selenium-diode rectifier with a 25Amp Schottky-diode type (I know some have already carried out replacement, predominantly with a silicon-diode type from Radio Shack, with great results) -- my pic below. The rec and heatsink are http://uk.rs-online.com/web/search/sear ... m=629-0041 and http://uk.rs-online.com/web/search/sear ... rm=103-960 respectively; I drilled the heatsink and locked the rec to it using an M5 x 40 machine screw.
The rec has the advantage of a low forward-volt attenuation of 1.1V, as opposed to the selenium figure of circa 3V. There is no evidence of overcharging as yet, as I haven't needed to top up the batt's electrolyte.
Charge current before this change - @ 4000rpm, : 13.40V / 2.8A, parking light on
And after - @ 4000rpm, : 13.65V / 3.0A, parking light on
Now, I realise that these increases are relatively small-beer, but time and extended use will tell. I'll keep you all info'd. I've only made short excursions before testing yesterday, the voltage and current measurements being carried out using Fluke calibrated DMM and clampmeter.
Sorry for the quality of the photo; I have to use my 1.3Mp phonecam now that Cowbag has left and taken her Sony camera!
Regards to all,
Steve