My CB77 No Longer Charges the Battery

G-Man · Post by **G-Man** » Fri Jun 27, 2014 12:53 am

Sara

I'm reluctant to mention this as I think you have discovered the culprit in the "case of the missing volts'.

BUT - if you were very careful you could put your 110 vac from a wall outlet into the AC side of the podtronics and hook it up to the battery or a bulb.......

G

sarals · Post by **sarals** » Fri Jun 27, 2014 1:11 am

G-Man wrote:Sara

I'm reluctant to mention this as I think you have discovered the culprit in the "case of the missing volts'.

BUT - if you were very careful you could put your 110 vac from a wall outlet into the AC side of the podtronics and hook it up to the battery or a bulb.......

G

:)

G-Man · Post by **G-Man** » Thu Jul 03, 2014 4:44 am

Hi Sara

I spoke to Rob "the Magnet Man" yesterday and he made a few comments on the Honda Alternator.

a) When off the bike, it is better to store the rotor inside the stator. This helps stop any decay of the magnetism. I remember this from my Brit bike days but I'm not a very good practitioner. This could mean that a NOS rotor is no better than one that's been on a bike for 40 years.

b) he reckons that it would be easy enough to re-magnetise the rotor with just the matching stator.

I'm going up to the factory next week and will take a rotor and stator to see what the effect is on it.

G

brewsky · Post by **brewsky** » Fri Jul 04, 2014 6:24 am

Sara,

Your issue got me curious regarding my dreams charging rate, so I decided to do a little checking yesterday.

Battery was at 12.5, key off, after sitting unused for a couple of weeks.

After starting with electric start, lights off, idle voltage went down to 12.3.........revving it up, it only maxed out at about 12.7.....

Turned ignition switch to lights on, not much better....12.1 @ idle and about 12.8 maxed out at high revs.....

NOT TOO GOOD!

Since I have an extra inline on/off switch in the headlight circuit, I turned the headlight off, but left the key switch to lights on, giving max charge from the alternator.......still wouldn't go above 13 Volts.

Went for a ride and immediately repeated the readings when I got back.....much improved.

13V idle, 13.7 at rpm, 14.8 and rising with headlight off, but extra alternator winding kicked in.

Key off, battery voltage 13.2......but very slowly discharging back to normal.

Conclusion seems to be that the battery is a pretty effective shock absorber for the varying system voltages, and very slight differences in battery charge state will dramatically affect the voltage readings.

It may be worth strapping a DVM to your gas tank, and taking a ride with it connected to see your actual readings while running.

I've done this before on other bikes..........not especially pretty, but tells the real story.

I have also used the small cigarette lighter type digital volt meters..... they are a little slow to react to varying voltage readings, but they do work.

I'm still hoping that at worst, you may have a battery issue, and maybe not even that.

Please keep us informed on your progress.

G-Man · Post by **G-Man** » Fri Jul 04, 2014 7:25 am

Brewsky

Good bit of experimentation! As you suggest, batteries are a very good voltage control on their own as they react very slowly. That's why I asked Sara to do some measurements with just a bulb.

I have to go through all of this myself soon so it is very interesting. Kind of Crowd Sourced research! :-)

G

sarals · Post by **sarals** » Fri Jul 04, 2014 11:14 pm

Fellas, this is good stuff. I plan to ride the Old Girl a little later this week (end), and I'll figure out a way to put the DVM where I can see it. So far she seems to be charging with the rectifier in the circuit.

Graham, I think it was you that sent me the YouTube link where the fella uses the stator coils to recharge the magnets on the rotor. It makes sense that it would work. The problem is having a source robust enough to deliver some hefty amperage to the stator, it seems.

Brewsky, your charging system is behaving very much like mine is. Could this be normal? I think so. Oh, yes, that battery is a voltage sink/buffer for that charging system, it seems. If I read the schematic correctly (and that I'm not that good at that), the alternator is supplemental, the battery is the source of power for the electrical system, except when the lights are on (then the pink wire coil supplements the system). Right? Maybe?

Good discussion!

G-Man · Post by **G-Man** » Sat Jul 05, 2014 1:47 am

Sara

I'll let you know what Rob tells me when I visit him. Th important number in re-magnetising the rotor is the number of ampere-turns. He seems to think that a standard 12v supply will do. Just have to work out the alignment of North and South Poles and then "spark her up" as we say..... :-)

G