Well....maybe I should be more worried about my rectifier.

I have no running lights, an LED tail light, 2 small LED license plate lights, and my Silverstar 55/60 Watt headlight bulb.  I have an Earth-X lithium Ion battery.

I really don't have much of anyplace to add any lighting on the Cafe bike.  Maybe I need electric socks?

I'm not an expert on the electrical system of this bike....I just have quite a bit of electronics/electrical experience and can only draw conclusions from the info available.

It seems to reason that if the bike produces 100-125 watts while running at 45 mph in 4th gear, and all original equipment is installed....that whatever is not being used by the bike to keep it running and keep the assorted lights on is being used to keep the battery charged. Anything not used by the battery is burned off as heat from the regulator/rectifier.

Simple math says that an all-original equipment Savage uses roughly 80-90 watts just driving down the road at 45 mph. any additional power generated by the bike that is not used is sent to the rectifier/regulator where it is burned off as heat.
Worst case scenario happens when the high beam is on, turn signal is on, and brake light comes on. In that situation very little power is left to go toward charging the battery, but seeing as this condition only happens for short periods of time....it isnt an issue.

So if your bike is stripped of most of the stock lighting, then you are sending more power to the battery charging circuit....and what cant be used there, is being burned off by the R/R. Could this condition "overcharge" the battery? I really dont know enough about the charging circuit to answer that. Will the unused power cause a pre-mature failure of the R/R due to it overheating? Again, I cant swear that it will....but science and logic says that if the R/R is designed to handle between 25-35 watts of excess power, and you are forcing it to deal with over 50 watts.....that could be an issue.

Do the guys at Ryca have any input on the Regulator circuit for naked bikes and conversions that remove most of the stock lighting?

I know from experience that LiIon batteries (or any battery really) does not like to be over-charged. Have you ever put a meter across the battery while the bike was running to see how much voltage is there?

The information that Stu has worked out about the amount of watts is really useful - I have wondered how much over-capicty a stock savage has for quite a while.
I also think rectifiers may possibly be able to handle a fair amount of excess power. If I think of other bikes I have owned - they usually didn't have an "always on" headlight. Thus there was quite a differentiation in running watts - during daytime running (no headlight, rear on brake only) vs nighttime running (headlight and tail light on). I hear of people cooking rectifiers but have never met anyone. I think rectifier failure may be mostly down to shorting. However others know much more than me, so am all ears on this thread, as am literally in the middle of rewiring my savage and will take your knowledge on board.

I've seen the square mounting point on the fender referred to as the regulator rectifier heat sink.  I don't remember if it was in the owner's manual, the Clymer manual, a parts guide, or somewhere else, but you're right about it.  I think that's the reason mine was cooked.  The PO had added saddlebags to the bike and just remounted the r/r to the saddlebag yoke.  There was a lot of heat build up there.  So much so that I couldn't touch it bare handed after running awhile. It had even melted the laces on the yoke.  When I replaced it I modified the yoke and made a space for it to be mounted to the fender again.  So far so good.  It'll get really warm but not hot enough to be uncomfortable to the touch.

HondaLavis wrote on 10/06/15 at 08:49:24:


At the risk of seeming argumentative, I'd have to disagree with you on this.  To say that steel isn't a good conductor of heat is just incorrect.  I mean, you could make the argument that when comparing steel to silver or copper that steel isn't as good, but you could also make the argument that steel is a great heat conductor when compared to tin or iron or most other materials.  You could also make an argument that some types of steel are better than others.  For example the steel in our fender is a much better heat conductor than stainless steel.

The bottom line is, the steel in our fender is a good heat conductor, and the design of the fender makes even better.  I mean, we wouldn't expect great heat dissipation for the r/r sitting it on top of a stationary 20lb block of steel, but the Savage fender is relatively thin sheet that has consistent high velocity airflow.  

That's my 2˘ but don't take my word for it there's plenty of science out there on this.

verslagen1 wrote on 10/06/15 at 14:28:22:


Succinctly stated  

I do believe the fins were cast into the rectifier for cooling - but then Suzuki hid it underneath a seat that most likely restricts the air flow considerably.

I also believe the fender is intended to be a heat sink, as Suzuki made a nice flat spot on the fender so it could be in full contact with the fender.  Even painted steel does a good job of moving heat around, and the Savage rear fender certainly has some thermal "mass" to it.

How hot does it get....dunno - I never really thought about it before.

If the folks who are hiding their rectifier in the plastic air cleaner box aren't overheating them.....I guess the rest of us don't have much to worry about.

Most likely when Boogie with Stu actually starts testing and reporting...he should open up a new thread and not get all this rectifier discussion in his test.