Actual charging system output in watts/amps???

[Guest]

I've been doing some reading here and elsewhere as to the GS charging system (specifically the 1981 GS1000G). For my fuel injection project, I need more power than the stock system can deliver as far as I can tell. At this point with LED bulbs, it looks like I'll need at least 21 amps while riding (this does not add in for brake lights or turn signals since they are not on all of the time).

The only concrete number I have seen is in the PDF shop manual, where it rates my bike at 18 amps. UPDATE- the 18A was for the original (1978?) GS1000. There is no number for the 1981 GS1000G output other than 80V no-load at 5K RPM. Apparently the R/R is different for this year as the shop manual supplement lists it as different than the 1980 GS1000G.

My bike has a Rick's electric stator and a Compufire R/R. As it is, I see 14.25V while riding. I know there have been claims of +20% output with an aftermarket stator, but was wondering if there is any actual testing or data for this?

I found a site that lists a how-to, but I lack the proper meter, plus the engine is out of my bike right now.

[Steve]

Posplayr did some testing a while ago, I think he found about 23 amps available, but I don't know what stator or R/R were involved.

.

[tkent02]

At this point with LED bulbs, it looks like I'll need at least 21 amps while riding

This seems really high, what is the big draw besides the fuel pump?

[koolaid_kid]

This article claims the GS1100E has an output of 230 watts
GS1100E wattage rating

[GS1000G Shopper]

Thanks for the info.

It really adds up- I'm using what data I could find from other similar setups and some basic math, i.e. injectors rated at 11-16 ohms at an avg. 13.5 ohms at 14V will be 1.04 amp each. Here is what I have as a worst-case scenario:
Headlight (high beam) 4.29A (new LED units save an amp here but are $210)
Heated gloves 1.57A (winter only)
Coils/ignition 5.00A (A site I found reported 2.4A each, perhaps a lot more, 14.0V / 3 ohms= 4.6 amps each)
LED bulbs .34A
Phone charger .10A
Add-on gauges .26A
Microsquirt 1A
Fuel pump 3A (this is the main problem area I can do something about, modulation will help reduce this)
Heated O2 sensor 1A (while running, more to heat up)
Microcontroller .10A
Injectors 4.16A

This totals 20.82A or about 292W @ 14V.

[tkent02]

I think the injectors and ignition use less, the biggest load is only happening part time? With the ignition, the coil only flows current for part of each engine cycle. Injectors only take current when they are open, which is usually not much of the time except at full throttle? How often will you be at sustained full throttle on a cruising bike? A charged battery will take up the slack if you use too much current for a little while.

A non heated O2 sensor is fine, it just takes a little longer to heat up which doesn't matter at all since you are not trying to impress the EPA with how quickly after a cold start your exhaust goes clean. Once you are cruising it just doesn't matter. MS can work just fine with no O2 sensor at all.

Do you rally need the heated gloves and the phone charger both at the same time?
In Florida? Oh wait, never mind, it's N. Florida.

Anyway I really love the fact that you are doing all of my homework for me, and being so thorough about it. Carry on.

[GS1000G Shopper]

I looked at the shop manual again, and the 18A was for the original GS1000. I've updated the first post. Apparently the later systems were more robust, so hopefully this is a non-issue.

[GS1000G Shopper]

I think the injectors and ignition use less, the biggest load is only happening part time? With the ignition, the coil only flows current for part of each engine cycle. Injectors only take current when they are open, which is usually not much of the time except at full throttle? How often will you be at sustained full throttle on a cruising bike? A charged battery will take up the slack if you use too much current for a little while.

A non heated O2 sensor is fine, it just takes a little longer to heat up which doesn't matter at all since you are not trying to impress the EPA with how quickly after a cold start your exhaust goes clean. Once you are cruising it just doesn't matter. MS can work just fine with no O2 sensor at all.

Do you rally need the heated gloves and the phone charger both at the same time?
In Florida? Oh wait, never mind, it's N. Florida.

Anyway I really love the fact that you are doing all of my homework for me, and being so thorough about it. Carry on.

I'm thinking the actual numbers will be less than my worst-case ones.

Semi-off topic, having worked in S. FL for a long time, I was surprised at the difference in the winter and the lack of difference in the summer. My beloved red GS was snowed on a couple of years ago on Christmas weekend, and the blue one rode through 104 ambient (in S. Georgia) earlier this year.

You're welcome. Hopefully I won't fry too many of my own circuits trying to figure out the added circuits for the bike.

[posplayr]

Posplayr did some testing a while ago, I think he found about 23 amps available, but I don't know what stator or R/R were involved.

.

I think that 23 amps was shorted current inside the stator not something available to the system.

The average is about running current (stock) is about 14-15 amps. I have not loaded my system down to see where the maximum output is. I suspect it is not over 20% extra which would occur at about 3000 RPM. That seems to be where stator current peaked in the SHUNT regulators.

[GS1000G Shopper]

This is a dumb question, but I'm not sure I know the answer. Will the Compufire series R/R give more amps than a shunt type or is there no difference? It seems like either would output the maximum the stator can generate if there was a demand for it.

[GS1000G Shopper]

Maybe a few of these will help, I can install them on the rear tire (I remember having one of these on my bicycle as a kid):

[rustybronco]

This is a dumb question, but I'm not sure I know the answer. Will the Compufire series R/R give more amps than a shunt type...

If the shunt type R/R doesn't use Mosfet's then yes.

[GS1000G Shopper]

OK, so when the bike was made and it was rated at 18~?? amps, this was with a shunt style R/R, so in theory with an aftermarket stator and series R/R I'll have more power! (nod to Tim the Toolman)

[rustybronco]

This totals 20.82A or about 292W @ 14V.

Why do I recall seeing a figure of the stock system being around 290 watts total output??

[daturat100r]

Maybe a few of these will help, I can install them on the rear tire (I remember having one of these on my bicycle as a kid):

I had a look at putting one of these on my gs but they only 4.8v so would need 3 in series to get the voltage correct