Battery and Charging: Revisited

Six year old battery now:

Yeah I know, replace it.

Running Boyer Power Box.

Ride for coffee six miles, have coffee, bike won't start, no headlight, no horn, not a damn thing.

Borrowed a trickle charge and waited two hours outside Starbucks for it to charge a little.

Ride it home, put volt meter on it, says 12.5, then turn headlight and tail light on for three minutes, reads 11.9 volts.

Recharge battery again a couple hours on trickle, start bike, reads 12.5 volts, increase throttle, still reads 12.5.

Deduce that I have both shot battery AND no DC current coming out of Boyer Power Box and charging battery

Order new single phase rectifier from Rabers in California, will be here later today, and hook it all up with new battery just purchased and now all charged and waiting.

Nice story so far, huh?

Two questions: Am I correct that the difference between the Boyer Power Box and my new simple $50 rectifier is only that the Boyer allowed the bike to run, once started, without a battery in place?
And the new rectifier must be connected to a batter to start and run?

Also, where to ground the new rectifier?
Good idea to ground it directly to a frame part, like one of the oil filter bolts through the lower cradle?
Or maybe ground it directly to the long bolt that holds the case together at the left rear of the motor?
Make any differnce for the ground, motor or frame any better?

"Air flow": instructions say it should be mounted with air flow for cooling.
I have had the Boyer Power Box in the battery area for ease of hooking up alternator and live charging wires.
Any better ideas where to mount a rectifier?

Rectifier or power box? I think you are confusing the two, but I may be wrong. Rectifier only makes DC for the charging and there is a separate regulator, originally a zener diode. Power box or similar is combination of rectifier and regulator (transistors) that keep the battery from over charging. Grounding is necessary for all components to work correctly with the battery. When I rebuilt mine, I still used rectifier and zener, so made sure good ground at rectifier, good ground at positive terminal connected to coils and timing area, and made sure there was a good connection from the engine to the frame. On the early bikes it was a wire from the bottom engine stud to the frame under the prop stand. There are many ways to make sure the grounding works, some use extra wires, but I think that's overkill unless there are no good grounds to the frame. Lots of times the frame grounding gets rusty and doesn't work very good and then extra wires are used, but can also be improved with good frame grounding.

Dave
69S

1up3down said:

Deduce that I have both shot battery AND no DC current coming out of Boyer Power Box and charging battery

Click to expand...

When a battery is worn out it can still take a 'surface charge'. Hook a voltmeter to it and it will show a charge, put a load on it and the voltage drops. I think it's not a question of having a shot battery 'AND' no DC current coming out of the BoyerBox. It may be a matter of the shot battery dumping the charge. Similar thing happened to me on my VFR this spring. Marginal battery was kaput. Could be the Boyer Box is actually just fine. Before you pull the Boyer, fit the new battery and see.

Six year old battery? That's a record.

Spend some coin on a battery ,clean up your ground(s).

Are you sure your charging system is working? I guess you can't run your bike without a battery (alas points).

1up3down said:

Six year old battery now:

Yeah I know, replace it.

Click to expand...

Yep, and buy a good one. 8)