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Discussion Starter · #1 ·
I'm having charging issues with my 74 cb450. Battery is good, but just not getting a proper charge. I'm running headlight, tailight and kick only, so that everything. I did find loose ground to the rectifier which was reconnected and things have gotten better for about a week and now it's back to discharging the battery if I run the headlight. I checked the connections at the headlight and they are all good. So I think its possibly the rectifier. Has anyone upgraded theirs, if so, with what?

thanks
 

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I did, with a single phase regulator rectifier. This sorted out the problem with the old rectifier, however I am still not 100% sure that I am getting enough out of the generator.

It has beeen suggested, and more than likely correctly, that a regulator would reduce the voltage from the AC delivered to it. I need to do some measurements on the AC output but have not got round to that just yet.

I know that there are several comments about using a standard silicon rectifier as a direct replacement.
This does work for sure and would be much less costly that a regulator rectifier.

Its just that I have the issue with using the battery as the ballast. This is a very old design and does cause battery degrading more that a constant voltage value from a regulated charge.
 

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Discussion Starter · #3 ·
Sorry I totally forgot about this. thanks for the reply. Do you have any suggestion for a brand to look for or where to find a regulator rectifier in one? I'm still having the charging issues, and I am really really wanting to run a brighter headlight bulb so I don't want to have to charge up every two days. I ride to work every day and I just don't use a headlight because of the charging issues. It's left me stranded once. Fortunately I was only a mile from home and pushed it.
 

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IF the rectifier is good, it CANNOT/DOES NOT allow electricity to "reverse flow" and discharge the battery....Diodes ONLY flow current in one direction, so this simply can't occur unless diodes are shorted (Bad), and then it also wouldn't charge the battery....... I would be more inclined to suspect a bad/weak/defective battery.......
What is your AC output, and what are the 3500/4000 RPM DC voltage readings at the battery?
 

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Discussion Starter · #5 ·
I think you could be right about the battery I worry, because the output is like 13.4 at 4000rpm's whereas idle is at 12.6. Even so, I think it would be nice to upgrade the regulator rectifier. I'm going to see how another battery is in my bike. I need smaller than stock though as I want to hide it as much as possible. The current battery I have is 12v 6ah and measures 5"wide and 3" deep and 3"tall. If I can get better and smaller that would be great.
 

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The battery you have now is only 1/2 the systems requirement .... You MIGHT get away with it on a racer (only powers the ignition), but NOT with lighting..... I recommend at least 9ah IF you are kickstarting ONLY......6ah won't get it.....
From your output numbers, there is NOTHING wrong with your charging system.......
IF you run less battery than you need, you should expect it to overwork and die......
 

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Discussion Starter · #7 ·
I'm running headlight and tailight only, no gauges or indicator lights and I am kick start only. I can't imagine that 6ah isn't optimum for that system. I've seeen setups like mine running 4.5ah with no issues.
 

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Steve is spot on with the battery. There is a reason that the battery was speced for that bike, it was because the engineers knew what would be requied to run it correctly with the technonogy of the day.

Dont forget that the coils take a reasonable wattage too although that doesn't show as an obvious light etc the will add load to the requirements.

Additionally if you are using the battery as ballast for the charging system (no Zener diode or regulator) then all the DC output from the generator will be going thopugh the battery and heating it up. This in turn could cause the plates to buckle.
I have gone back to using a Yuasa battery, expensive but definatly worth it. You get what you pay for, and cheap batterys are not necessarily low cost options over time.
 

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Pawn....
It isn't your charging system....
If it also isn't the battery,..... what's left?....

I guess you could have a short somewhere in the wiring, OR, considering it only occurs when the headlight is on, you could have the wires that "add" the extra charging coils cross connected to where they subtract from the charge rather than add to it.... (check charging voltages at battery with headlight on)....But my best guess is still an inadequate battery......
SOME battery types will NOT accept charging beyond 20% of their AH rating.... If this is your case, you've already cooked the battery.........
 

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Discussion Starter · #10 ·
i'm not really saying you are wrong, by all means you are probably correct. All I'm saying is that I find it somewhat astonishing when I see people running a smaller battery than I and they aren't having any charging issues. I have a lot of loose ends on the harness that I need to go over and clean up, so it could also be that. I know there is a green wire coming from the regulator that finds it's way loose from time to time, although I make sure to check it. It has popped out twice, so that could be the culprit there.

I suppose what I would like to get out of this thread is a suggestion on a good replacement single unit regulator rectifier so I can have it on hand when I redo the whole harness and get rid of the things I am not using.

Also one other problem I found, yesterday, that I didn't even realize I has was my brake switch from the rear brake pedal was always engaged. Since I never see it when I'm riding I had a friend tell me the brake light wasn't working but my tail light was very bright. So I replaced the stitch yesterday as well as the spring and now the light remains a tail light until I hit the brakes. So I imagine that was adding a very small bit to the issue.
 

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The regulator's green wire coming loose would ALLOW overcharging, possibly cooking the battery....( It can't shunt the excess to ground if it's not grounded).....
The rectifier's green wire coming loose would prevent re-charging the battery ...(you'd be running "total-loss").....
Either scenario for very long or repeatedly while running would/could permanently damage the battery....
Constant Brake-light without the headlight switch making the "overcharge" connection would also drain the battery.....

As for a single unit reg/rect, I can't recommend any.... I prefer to just replace the bad one if it occurs, so I run the stock components.....
 

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Discussion Starter · #12 ·
ok, so in this case then I've possibly fixed the situation by addressing those two issues. I hope to see if that fixed it, or at least if the battery is fried and simply drains at this point. Thanks for the help guys! This is why I come to this site!
 

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Discussion Starter · #14 ·
i will. I should know if it's sorted by mid week or the end of the week. I'll post up what I find.
 

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Discussion Starter · #15 ·
i don't want to jinx myself, but the charging seems fine! Hopefully after posting that something is going right with my bike, nothing will go wrong to even itself back out :p
 

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That constant brake light you had on may have helped you not cook the battery so if it were me :D 12v 12AH, had too many problems in the past with bomber batteries,why go off spec. :D
 

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I've only had a bike shut off/charging issue once.
Runs like a champ!
however, my multi-meter read at 12.27 before I left to ride. I don't ride too fast and was recommended to keep RPMS up to charge.
In my driveway, battery did charge a little when revved 3,000rpm.
so, after 30 min. of riding...would not turn on! so....screw pushing a bike home, I just walked my battery home! threw it on a charger for literally 10 min. and walked it back. no prob.! fired right up.

so....can I assume that I should ALWAYS charge my battery before I ride no matter what? AND, don't foresee longer than 60 min. rides in my future, which is what I like doing anyways.....

any insight is welcome. My digital multi-meter did say 12.27 this morning though....30 min. later, bike would not turn on. hmmm.
I never knew about Honda's charging issues before!
 

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oh and....I wasn't running any headlights when it happened.
I am a big fan of electric starting, though. I made it a point to have that 100% good to go for this season.
previous, un-related foot injury makes kickstarting a damn chore....
 
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