Full Electrical Draw on OEM Equipped SWing

Disclaimer: I'm not an electrickity kinda guy so I have some questions.

1. I understand our generator/stator produces approx. 441W at around 5K RPM.  What amount of this is used by a "standard" OEM equipped SWing? (no upgrades or accessories)

2. How much capacity (how many unused watts) are left over from the 441w maximum output?

3. What happens to the excess capacity if it is not used?  ie. where does it go?

Thanks.

Can’t answer 1 & 2, but for 3, the excess capacity is dissipated as heat at the Regulator/Rectifier. That’s why the big lump heat sink R/R body.

From a post in 2012 not sure how accurate it is.


The Silverwing typical base load is as follows:
Headlight 55 watt high beam (normally off)
Headlight 55 watt low beam (normally on)
Brake / tail light lamp 21 watt brake (normally off) / 5 watt taillight (normally on) two lamps
Front turn lamps 21 watts each (normally on) two lamps
Rear turn lamps 21 watts each (normally off) two lamps
License light 5 watts
Fuel pump estimate 10 watts ?
ECM estimate 10 watts ?
Ignition coils estimate 60 watts each ?

Total base load is approximately 252 watts. The alternator maximum output is 441 watts. Subtract the base load from the alternator output results in 189 watts remaining to run accessories and to charge the battery.

With a low battery, any current the alternator produces above the 252 watt base load would be used to charge the battery.

With a fully charged battery, the regulator switches on the SCR’s earlier to dump the extra 189 watts to ground.

Good find Marvincon ... thanks ... and I did consult my friend "Search" before I posted my question. Out of curiosity, what did you use for search criteria as I came up with nada on this topic?

What are SCR's?

So I just did some arithmetic and 252 is indeed the lowest possible draw with 189 watts left over. Even riding with high beams constantly on (this might happen), that would use up another 55 watts for a max total of 307 watts allocated.  Subtracted from the 441 max. watts generated leaves 134 watts available for accessories. This is, of course the worse case scenario of usage and assumes a good battery.

It appears the 56 watt (28w per side) auxiliary lights I want to install should be no problem then. Even leaves some capacity for other add-ons like GPS, hand warmers etc.

Like Dan Spevack asked in one of his older posts, "has anyone ever heard of a SWing owner running out of electrical capacity?"

SCR = silicone controlled rectifier. That’d be the three diodes in the R/R. 

Yes indeed, electrickery. More information than you need:   

https://en.wikipedia.org/wiki/Silicon_controlled_rectifier

Cosmic_Jumper wrote:

SCR = silicone controlled rectifier. That’d be the three diodes in the R/R. Yes indeed, electrickery. More information than you need:   

https://en.wikipedia.org/wiki/Silicon_controlled_rectifier

Thanks Tim. Nothing like a little break on a holiday Monday for a Greek lesson.

Further, I talked about the electrical mods I want to do with someone who is very knowledgeable about 12v electrical systems and he asked me these two questions.  I have no answers so I throw them out to the collective brain trust here ...

First Question

What is the stator output when at idle (~ 1,300rpm)?  He says "You don’t want to draw from the battery every time you stop at a traffic signal.  In fact, you want to be able to charge the battery – within a short time, even while idling."

Second Question

What is the amperage of your starter motor? I.e. How many cold cranking amps (CCA's) do you actually need to start the scooter?

I searched the various forums and the Factory Service Manual and I came up with nothing.  Anybody know the answers?

OMG Bug, unless you’re planning on running klieg lights you’re way overthinking this.

Trust Honda. Trust Dan Spevack. Fuse the circuit.

~1300rpm is going to be ~14.5V DC.

Thanks Tim, I guess I didn't share the full story.  I'm also planning at improving/modding just about every light on my new-to-me SWing, adding grip warmers, a 12v outlet for various applications (GPS, CB radio, phone charging etc.)  This doesn't even include a heated seat and/or heated clothing.

So, since "my guy" is a design expert in 12v transportation lighting systems, he wants to know what he's dealing with as we (he) plans out circuits, loads, adding a power distribution box etc. plus I hate running a bunch of wires directly to the battery as many accessory providers recommend. Too messy.

Like I said in my first post, I don't "get this stuff" but he makes a living at it and I believe in listening to experts ... and not going by "gut field".  If nobody knows the numbers here, that's OK.  We'll have to get at things in a little different way is all.

Hope that gives some context behind my questions.

Keep adding until you blow a fuse. lol

Murf wrote:

Keep adding until you blow a fuse.  lol

Certainly one way to test the limits Murf ...    

... and it's not dissimilar from how I determine total range for the fuel tank ... by literally riding the SWing until it runs out of fuel (or at least until it starts to display symptoms of fuel starvation i.e. chugging).

So, since "my guy" is a design expert in 12v transportation lighting systems, he wants to know what he's dealing with as we (he) plans out circuits, loads, adding a power distribution box etc. plus I hate running a bunch of wires directly to the battery as many accessory providers recommend.

While it may be messy cutting / splicing into OEM wiring MIGHT get unwanted results, using the extra wire and dedicated fuse block separates one problem from another.

oldwingguy wrote:

... snipped ... While it may be messy cutting / splicing into OEM wiring MIGHT get unwanted results

We actually spliced and soldered into the existing lighting wires when we installed customized run/park/turn LED's into my previous GIVI V46 topcase and LED lit (run/park/turn) license plate holder.  That was pretty straight forward and did not draw much power being LEDs. He's thinking a separate distribution box MAY be the way to go this time given the number of electrical modifications involved.

oldwingguy wrote:

... snipped ... using the extra wire and dedicated fuse block separates one problem from another.

I do not know what this part of your post means.  What extra wire? ... and if a dedicated fuse box is used, what problems does that create? ... and is separating one problem from another a good or bad thing?  Clarification please. Thx.

A good thing, putting accessories on their own fused circuits takes them out of the OEM circuits. Having a dedicated supply and ground for them is a good thing. I saw a lot of G'Wings that had electrical problems by tapping into OEM harness assemblies. You are correct with a good solder and shrink tube on any wiring and even adding small wire ties to prevent abrasions. When I ran small wires I would fish them through 02 tubing in areas that may chafe wires.

Gary from Manitowaning, Ontario, Canada here. Just bought a 2006 FSC600A so this is my first post.

This electrical wiring topic is of immediate interest to me so here goes: I have the same concern as sonuvabug about the SW's alternator capacity of 441 watts but still plan to go ahead with adding Oxford Heaterz grips, Moose seat heater and installing a 12V accessory receptacle in the factory provided left glove box location for my GPS and cell phone charger. I bought the 6 circuit PDM60 Power Distribution Module but am searching for the best strategic location for the deck-of-cards sized unit. Possibilities include stealing the front portion of the luggage box or maybe somewhere under the right glove box. Yesterday I attached a Ctek battery charging pigtail to the battery terminals and even that added too much bulk to fit the battery cover properly back into place. Too bad that the luggage box light doesn't have a switch, so that it can be turned off when the seat is not fully latched during charging. Actually I use a popsicle stick to pop the bulb out during extended maintenance; the good thing is that it matches the prop stick I use to help the seat damper keep the seat up. Also, I will add the brake light option to the Givi Simply E450 top case but will do that by splicing into the rear brake light wiring like I did on my 2014 Forza. Issues like wiring sizes & routing, switch mounting and weatherproof quick disconnects all come into play in this relatively simple project. Ok enough about me and my project: has anyone out there already added a PDM60 to their Silverwing? If so, how did that go?