Topic: Which rectifier to buy?

[amitr0]

My voltage regulator is faulting, it sometimes sends more than 15.75 volts to the battery when RPM increases. This causes fuse blow outs and heating up of fuses too. Also the battery is getting damaged.

I am trying to swap with an after market combo model, but there are so many choices that I am unsure which one to go for.

PO upgrades the points to a dyna EI system, but didn't upgrade the stock coils. The spark is weak so I plan to upgrade to this :

https://4into1.com/magna-5-ohm-coils-and-caps-honda-cb350f-400f-500k-550/

So the regulator/rectifier must be compatible with it as well.

I know some of the links below are for lead acid others for lithium ion battery types, i don't mind upgrading the battery too, probably should be done as the voltage regulator was sending higher voltage to it for a long time

Here are some from 4into1, but therr are others too ..

https://4into1.com/regulator-rectifier-lithium-lead-acid-honda-cb350f-cb400f-cb500-cb550-cb750/

https://4into1.com/rectifier-three-phase-charging-system-honda-cb350-cb400f-cb500-cb550-cb750/

https://4into1.com/ricks-motorsports-electric-regulator-rectifier-for-lithium-batteries-honda-cb350f-400f-500k-550f-750f-750k/

https://4into1.com/electrosport-honda-rectifier-regulator-combo-cb350-cb400-cb500-cb550-cb750/

https://4into1.com/ricks-motorsport-electrics-honda-rectifier-regulator-combo-cb350-cb400-cb500-cb550-cb750/


Please suggest the one I should go for, or an alternative if there is one.

[Bodi]

I don't have a recommendation. An adjustable one might be best if you ever might want a lithium battery?
Before you jump in, confirm that yours is bad. The OEM one rarely fails. Measure voltage from battery "+" to the black wire on the regulator with bike running (reasonable RPM, around 3000) and headlight on.
This voltage will be added to the battery float voltage by the regulator. So if you have 1.5V there, the regulator will try to get it up to 16V - 14.5V (normal float cutoff voltage) plus your 1.5V.
Overcharging is usually caused by this: corrosion and age make the harness connectors slightly resistive. Cleaning them all solves this, adding a relay controlled by key on power and connecting battery "+" to the regulator (fused of course) will ensure a reliable battery sense voltage there.

[amitr0]

I don't have a recommendation. An adjustable one might be best if you ever might want a lithium battery?
Before you jump in, confirm that yours is bad. The OEM one rarely fails. Measure voltage from battery "+" to the black wire on the regulator with bike running (reasonable RPM, around 3000) and headlight on.
This voltage will be added to the battery float voltage by the regulator. So if you have 1.5V there, the regulator will try to get it up to 16V - 14.5V (normal float cutoff voltage) plus your 1.5V.
Overcharging is usually caused by this: corrosion and age make the harness connectors slightly resistive. Cleaning them all solves this, adding a relay controlled by key on power and connecting battery "+" to the regulator (fused of course) will ensure a reliable battery sense voltage there.

Thanks. Will do the test first.

[seanbarney41]

I honestly can't recommend anything but the stock components.  In 15? years, dozens of different bikes, hundreds of thousands of miles on sohc4's, I have never had a single problem with a stator, regulator, or rectifier.  Several years ago I started using AGM batteries instead of lead acid.

[RAFster122s]

Clean up all your connections in the charge circuit, especially the ground points... Lots of charging system issues are caused by dirty or poor connections.

[amitr0]

Clean up all your connections in the charge circuit, especially the ground points... Lots of charging system issues are caused by dirty or poor connections.

I am new to the world of mechanics. Could you suggest what i can use to clean electrical connectors.

[Alan F.]

To clean up electrical connections I recommend green Scotchbrite pads:



Followed by CRC brand Lectromotive electric parts cleaner:



And afterward before you reassemble throw a dab of Dielectric grease on the newly cleaned parts:



Other brands are available, get what you can find locally. You'll want to use the electrical cleaner and dielectric grease on all connections throughout the bike, I recommend the Scotchbrite to shine up the connections that you can reach (not inside a connector) then use the cleaner and dielectric grease.

How much dielectric grease? Not enough will not cover the contact areas, too much will make a big mess. Somewhere in between is just fine. Wipe of excess with paper towels, wear rubber or latex gloves if you like.

[amitr0]

To clean up electrical connections I recommend green Scotchbrite pads:




Followed by CRC brand Lectromotive electric parts cleaner:



And afterward before you reassemble throw a dab of Dielectric grease on the newly cleaned parts:



Other brands are available, get what you can find locally. You'll want to use the electrical cleaner and dielectric grease on all connections throughout the bike, I recommend the Scotchbrite to shine up the connections that you can reach (not inside a connector) then use the cleaner and dielectric grease.

How much dielectric grease? Not enough will not cover the contact areas, too much will make a big mess. Somewhere in between is just fine. Wipe of excess with paper towels, wear rubber or latex gloves if you like.

Thanks much!

So this cleaner solution can be safely sprayed inside fuse boxes, bullet connectors and other 6, 8, 9 pin plastic connectors? Since i wont be able to reach inside the connectors with scotchbrite or otherwise, will that clean well?

[Alan F.]

Yup, just spray inside the conectors, it'll fizz and foam before it dries up leaving clean and shiny metal behind.
Scotchbrite is only for things you can realistically touch with it.

[Bodi]

Spinning a q-tip in the females with that cleaner is good.
If the clear plastic cover is burnt brown they should be cleaned extra well, then squeezed with pliers to tighten the grip. Any that don't snap together securely should also be tightened.
Burnt black cover... the female metal may have lost its spring and those should best be replaced but retensioning them will help a lot. The copper wire near the connectors may be charred as well meaning the wire is oxidized, brittle,  no good - this definitely needs new connectors attached to bright copper past where it's charred. Depending on the wire and where it goes, soldering clean ends together and using heatshrink insulation may be good, not good if what the wire goes to needs to be unplugged and removed.
Check the back of the fuseholder - if the clips heated up enough to melt the solder, a new fuseholder is best. Modern replacements with minifuses (plug in type) are available. After decades the clip plating has gone away and ideal contact may be impossible.
Switches mostly have a wiping action that keeps them in good condition. A shot of contact cleaner is probably all that's needed.
many engines have a set of 5 bullets under the left side cover for the 3 stator wires and the 2 field coil wires. With the engine heat and relatively high current, these tend to be in bad shape. Stripping then soldering them together with a heat shrink insulating cover works great - taking the alternator off gets a bit more difficult but is not impossible.

Going through the harness and resolving any connector problems avoids (or cures) may electrical gremlins.

[grcamna2]

subscribed

[amitr0]

Spinning a q-tip in the females with that cleaner is good.
If the clear plastic cover is burnt brown they should be cleaned extra well, then squeezed with pliers to tighten the grip. Any that don't snap together securely should also be tightened.
Burnt black cover... the female metal may have lost its spring and those should best be replaced but retensioning them will help a lot. The copper wire near the connectors may be charred as well meaning the wire is oxidized, brittle,  no good - this definitely needs new connectors attached to bright copper past where it's charred. Depending on the wire and where it goes, soldering clean ends together and using heatshrink insulation may be good, not good if what the wire goes to needs to be unplugged and removed.
Check the back of the fuseholder - if the clips heated up enough to melt the solder, a new fuseholder is best. Modern replacements with minifuses (plug in type) are available. After decades the clip plating has gone away and ideal contact may be impossible.
Switches mostly have a wiping action that keeps them in good condition. A shot of contact cleaner is probably all that's needed.
many engines have a set of 5 bullets under the left side cover for the 3 stator wires and the 2 field coil wires. With the engine heat and relatively high current, these tend to be in bad shape. Stripping then soldering them together with a heat shrink insulating cover works great - taking the alternator off gets a bit more difficult but is not impossible.

Going through the harness and resolving any connector problems avoids (or cures) may electrical gremlins.

Thank you thank you!

[Deltarider]

Most likely spots causing difficulties are: the fuses and their clamps (clean), the IGN key switch and a bad NEG path. Stock regulators are known very reliable. I do not recommend adjusting them, unless PO has messed with it. If you think of adjusting the regulator, it's my feeling, the problem is elsewhere.

[Maltboy]

I honestly can't recommend anything but the stock components.  In 15? years, dozens of different bikes, hundreds of thousands of miles on sohc4's, I have never had a single problem with a stator, regulator, or rectifier.  Several years ago I started using AGM batteries instead of lead acid.

I wish I had listened to you before I made the mistake of buying a combi unit.  It was defective.  Cleaned up the OEM regulator and rectifier, installed and adjusted the regulator.  Bam!, worked perfectly.  50 years old and still running strong. That being said, if someone is determined to "upgrade", then buy one from a reputable vendor like Rick's.  eBay junk is just that.

[Deltarider]

I honestly can't recommend anything but the stock components.  In 15? years, dozens of different bikes, hundreds of thousands of miles on sohc4's, I have never had a single problem with a stator, regulator, or rectifier.  Several years ago I started using AGM batteries instead of lead acid.

I wish I had listened to you before I made the mistake of buying a combi unit.  It was defective.  Cleaned up the OEM regulator and rectifier, installed and adjusted the regulator.  Bam!, worked perfectly.  50 years old and still running strong. That being said, if someone is determined to "upgrade", then buy one from a reputable vendor like Rick's.  eBay junk is just that.

Recently an engineer on the German forum stated the OEM regulator on his CB500 still works like new, after 47 years and 180.000 km. Also, in measurements, it proved superior to an electronic one.
Here's his explanation. When cold the regulator will show switch voltages of over 15 V. That's OK, the battery has just delivered a lot of power for starting. Not before some 10-15 minutes in operation, the regulator will reach its calibration temperature and will then switch at 14,40 Volt, +0,1 Volt max. He has repeated his measurements on two other OEM regulators he has and the results were the same.
So our OEM regulators cold switch at 15 V and once the calibration temperature has been reached, at 14,4-14,5 V, just like the shop manual says. If you have a conventional lead-acid battery, there's nothing to worry about. Modern batteries will need readjustment of the regulator however.
Electronic regulators do not charge better, they just consume less power themselves. (An OEM regulator: around 0,02 kW.)
The stock regulators are good quality and can be readjusted for any available type of battery.
The big green resistors at the outside of the OEM regulators also play a role in 'monitoring' the temperature, so to speak. When temperature drops, they will switch to full charge more frequently, increasing the charge. The engineer concluded: these are not only resistors, placed outside just for cooling, they also act as temperature measuring devices! The hotter, the sooner they will switch to less charge. So as soon as the resistors have reached the calibration temperature, the ambient air temperature will play a role. That's good, when we realise that the temperature of the battery also varies with the ambient temperature ofcourse. BTW, I don't know modern regulators that measure the temperature, let alone that they will adapt. Imagine you're in a traffic jam and you and your bike get hot. The OEM regulator will also sense this rise in ambient temperature and will reduce the charge accordingly to the also hotter battery. Simple and genial.
(Courtesy of Spinner)

[eldar]

I can't recommend, but something to consider is if you go lithium, you'll probably want an electronic and not the stocker. It may have changed, but when they were new, lithiums needed a smooth voltage regulation and it was suspected that mechanical regulators could cause a battery to start on fire. It was a discussion , here I think, years ago.
I never moved to lithium as they can require special chargers that are able to balance cells.

[BomberMann650]

I've installed Oregon Motorcycle Parts VRR's in 3 builds now.  They work a treat.

[Deltarider]

As long as my regulator works fine, I will stick to conventional lead-acid batteries. They live long, are forgiving when voltage should reach 15V, so no hassle with readjusting the regulator, as required by more modern batteries. Also I like the idea the battery's life begins the moment I fill it. You never know how old a sealed battery already is, when you buy it.

[eldar]

I always buy agm that I fill. Then I know when life starts.

[BomberMann650]

AGM are so finicky about their long term storage, and heat exposure, and rectifier goodness.  Managed to ruin quite a few with little effort on my part.

Recently switched to shorai lithium battery.  After a close call with a fancy antigravity design.  Though antigravity does make a good battery, i won't trust their internal bms circuits again.

Any current combination reg rec unit is suitable for lifepo4 battery use.  And can be ordered new oem.  Just have to make your own connectors.  I suppose the issues with over-volt temperature and AC/DC conversion remain.  But the super low discharge rate, and "give it all, all the time" cranking amps of lifepo4 are a benefit.  Along with the supreme lightness of the part.

OMP's adjustable units aren't much of a nuisance.  There are non adjustable options too. 

I do like the way hondas original v reg resembles a tattoo machine

[eldar]

Huh, aside from topping them every so often over the winter, I've never had an issue with agm. As with any battery, brand can matter .

[BomberMann650]

Huh, aside from topping them every so often over the winter, I've never had an issue with agm. As with any battery, brand can matter .

Had to warranty out a nice yellow agm battery within the few weeks it took me to build, test, and tune the trash triple bike.
Between lousy ebay reg recs, a failing stator, bad install instructions, and repeated discharge cycles.  It lost the mojo.
Then the fj killed another agm after the 40-days-&-40-nights social distancing tour.  One bad rectifier diode and dirty wire terminals weren't helping.  80,000 miles from an oem reg rec is pretty good so im not mad that mad.

At least im a quick learner when it comes to maintaining a good charging system.

[eldar]

Yeah, bad charging probably contributes more than anything else.