Would be the same as riding a fully charged bike.

Hmmm... I wonder if this is why some rectumfryers get hot?


The components to a rectumfryer.
3 sets of power diodes and a zener diode.

The power diodes make ac into dc, once the bat is charged, current should stop flowing.
The zener diode lops off anything above 14 volts, so no impact here.

Nope, the battery will charge faster then there should be a decrease in current.

The potential problem is that our rectifier can't regulate current - the charging system is always putting out the same amount.  Any power that isn't used to charge the battery or run the lights needs to be wasted as heat.

I have a20/40 watt led sealed beam and 2-15 watt led driving lights. I have driven over 15k this year with that set-up, including some 10 hour days on just low beam all day. Never noticed any excessive heat from the rectifier, and with my solo seat it's only a inch or two from my butt.

No, during the day I just use low beam (20 watts), just use the driving lights at night. At night with the driving lights it's 50/70 watts total. But when I had a regular H4 bulb (55/60 watts) it used 85/90 watts at night with the driving lights and never had a problem with the battery.

Interesting question about the Reg/Rec.
I owned an SV650 Suzi-Q for years. One of the chronic problems on the early (Gen 1) bikes was a toasted Reg/Rec. The usual solution was to swap out to a more zoftig R/R from a Gixxer.
Did some head scratching on that one.
The Gen 1 bikes hid the R/R under the tail section. Virtually no air flow.
A lot of the folks who toasted their R/Rs were hot shoes-track or fast street guys.
Got to thinking.
The SV, like the Savage, uses a permanent magnet alternator. In short, the alt produces more juice the faster you spin it. Redline on the SV was 10.5K
The fast kids were likely not using extra electrical stuff (heated clothes, stereos, coffee makers).
So, on those bikes, the alternator was producing a ton of juice, and it wasn't being used.
So, the R/R had to lose this extra juice, which it did by shorting it to ground and turning it into heat.
So the R/R got toasty, and toasted.
The other solution was to relocate the R/R to where it got some air.
So, in answer to the question about toasting the Savage R/R...
I guess if someone had twiddled their motor and raised the redline from 6K or so to 8K or so. And likes to rev the nuts off of the motor.
And the R/R was located somewhere that it never sees cooling air.
And the bike has a minimal electrical load.....
Then there might be a problem.
Rev it up with a meter connected and see how early and how high the voltage goes.
Point an IR gauge at the R/R after a long run and see how hot it is.

The R/R on my bike is the stock place on the r fender, but my seat is custom solo and does not come close to covering it. So it and the r fender have good airflow.
A good thing I guess.

Papa Bear wrote on 11/03/16 at 13:59:40:


You would think so! However, whatever current is not being used (i.e., 30 Watts) gets turned into heat. The R/R has to dissipate the extra heat even though it doesn't see the same amount of current as before.

justin_o_guy2 wrote on 11/03/16 at 18:01:26:


In the stock location, the rectifier is bolted to the rather heavy rear fender.  I do believe that most of the heat dissipation occurs from transferring the heat to the fender.....as there likely isn't a lot of air flow going on under the seat where the rectifier is located.