Max Current from an electrosport RR and stator.

[Mekanix]

Hi, I'm in the process of rebuilding an 81 GS and I've added heated grips and a heated two up seat

all together the bike alone draws 3 amps for the headlight and 2 for the ignition.

all the heaters combined draw 4.3 amps at 12.5 v battery supply

That's 9.3 Amps Vs the normal 5 amps

Can the Gs charging system keep up with that constant demand ?




thanks

 

[BassCliff]

Hi,

No, probably not. There is not a lot of extra juice available beyond what the bike needs to run and charge the battery. Many riders have one extra "appliance" like heated grips or a plug for a heated vest. But you probably have too much load for the GS charging system.


Thank you for your indulgence,

BassCliff

 

[duaneage]

Most GS charging systems are rated at 280 watts max, even less at idle. That's about 20 amps on a good day, significantly less at most speeds. These are great bikes but lousy electrical generators.

The stock RR is not going to last. Period. A Honda RR will do the job but the Stator is not going to put out any more than it's rated. Just doesn't have it.

Investigate LED tail lights and brake lights to free up some power, if you can get the draw down a bit to 8 you might be OK. I would not go to 10 amps or you are going to drain the battery at red lights and overheat wires in the fuse box area. If the battery gets weak or it's cold out the charging system is going to be taxed. And something has to give.

For what it's worth the main fuse is usually 15 amps and the rest are smaller sized. 15 amps at 14.0 volts is around 210 watts. If you have a 20 amp main the max is 280.

Honda RRs are supposed to be rated at 450 watts and were used on a lot of bikes over 30 years. Their extra capacity means no failures. I have not seen a bad one and I've tested more than anyone.

 

[Mekanix]

Hi,

thanks for the reply's,

I already have on order brake and signal led lights that should free up around 2 amps for the signals and over 2.5 amps for the brake light as well as all the lights in the instrument cluster are now led. and of course a proper led flasher with the 3rd pin. Just need a good led headlight but they're not that bright yet.


I don't really mind burning up this RR or stator as I have access to many honda and suzuki RR's and I rewind my own stators. Just thought i'd give the electrosport products a try. And I will be watching it very carefully when I finally get the engine in to start testing under load.


Thank you for the wattage ratings, I couldn't find that anywhere.


at Idle (1100) it puts out 13.4vdc at 5~6 amps and drops to 12.6 with brake and horn and turn signal on ~11 anps. But at 2.5K RPM and up its right up to 14.4 and no idea what the current was but It didn't seem to mind the load( all taken at the RR and only 0.2 V drop from there to the bat terminal).


I only intend to run the accessories temporarily or maybe one at a time to heat up then that's it.
The grips require 2.2 amps
Main seat takes 2.4 amps and passenger seat takes 0.7amps.(yeah that's right passenger gets one )

All are wired and fused to the bat terminals and all wiring is from the RR to the bat and ground are larger to handle the current.

thanks again,

I'll post what hapens

 

[Steve]

... all together the bike alone draws 3 amps for the headlight and 2 for the ignition. ...

Did you measure that or read it somewhere?

I ask because if that's all your bike is drawing, something is wrong.

I believe all the 81s (you did not say which one you had) had H4 headlight bulbs. Low beam on those is 55 watts. That is over 4 amps.
The coils are a nominal 3 ohms, so they will draw 4 amps EACH, for a total of 8. Add that to the 4+ of the headlight, you are over 12 amps already, not the 5 amps that you were talking about.

And, that is just the steady-draw stuff. The signals and brake light draw is substantial, but very low usage. In other words, they aren't on long enough to really matter, except that the brake light is usually on when the engine is idling and not charging the battery very well.

.

 

[Mekanix]

Hi,

Actually I'm using the original headlight but I have the lens for an h4 if I wanted to go that route but it does take more power and the lens doesn't focus as well as the original. I was just hoping to find an Led that would fit in there that was bright enough.

I took the readings myself. With only the ignition key on there is a steady 3 amp draw that is mainly the headlight with a few other lights in the cluster and the brake light on low. With the kill switch on it increases to 5.5 amps at 12.5 v (batt only). The coils only take two amps when the kill switch is on. and I will try triggering them and see if it increases.

Of course it will draw more current at 14.5 v.

Each coil is pulsed meaning its never a steady draw.

I cant wait to get the engine back in to get the accurate numbers

Its a 1981 GS 400L completely restored and I'm just in the final stages.

thanks

This is the before

April 9 2010

 

[SqDancerLynn1]

The ign and coils will draw more current as the RPM's go up too !!!

 

[Steve]

Each coil is pulsed meaning its never a steady draw.

Yes, it's "pulsed", but do you realize that it's ON much more than it's OFF?

By design, current flows through the coil, saturating the magnetic field as much as possible. When the rotor comes by the sensor coil, it very briefly interrupts the current through the coil and causes the magnetic field to collapse. This is what causes the high voltage pulse to the spark plugs. The current is then turned back ON so that it can spend as much time as possible saturating the magnetic field for the next spark. I can't say for sure, but I'm sure the duty cycle ON would be around 95%, maybe more, so don't count on the "pulsing" to diminish the draw of the coils.

.