kz1300 banner
Electrical

Second Alternator???

  • rdurost
  • Topic Author
  • Offline
  • Elite Member
  • Elite Member
More
4 years 2 months ago #27954 by rdurost
Second Alternator??? was created by rdurost
I have to admit that the very idea of doing this to the 1300 gives me pause, but I can understand it if Kawi thought its whole future for these bikes was in selling them as touring bikes.

As a person who is interested in minimum weight for my '82, and who has access to LED technology that didn't exist back then, I would much rather ditch the weight and turn the extra alternator over to somebody who needs it.

I also believe that the alternator is a "total loss" type that burdens the engine at all times with the same load, and shunts most of it to ground, most of the time, like my '77 Gold Wing. I have seen al lot of discussion on that side about substituting more modern regulators which don't burden the engine except to the degree they need to, and never heard anything negative.

I'll be doing some exhaustive searching on both topics, but the search engine on this site is very crude (sorry, just the truth) so if anybody has some quick links, or information, I'd sure appreciate it.

Richard

Please Log in or Create an account to join the conversation.

More
4 years 2 months ago - 4 years 2 months ago #27957 by Kawboy
Replied by Kawboy on topic Second Alternator???
I wouldn't be too hasty getting rid of your aux. alternator until you're satisfied that you have something that works. The 82's were very unique. The Main alternator was only used on the 82. I'm thinking the 82 was a tried model to prove that dual alternators could work. The 84-89 had a larger Main Alt with an Aux alternator.

As far as your question about the regulators goes. Jack at www.roadstercycle.com has your answer. The series regulator/rectifiers are definitely the way to go and Roadster Cycle is the only supplier of genuine Shindengen regulators I know of. The SH775 series regulator will do the job as proven by Neville but it might be taxed at 35 amps maximum with a maximum steady output of 27 amps. I think the SH847 with a maximum of 50 amps is a better choice but it's $50 more than the Sh775. If you're going full out LED's then definitely invest in the SH847 (as noted by Roadster Cycle). It's better suited for running with low charging requirements.

Please take the time to read Roadster Cycle's web page. Shunt regulator's which are the stock regulators or the Shindengen FH020AA or the FH010AA's are Stator Eaters. The series regulators ( SH775 or SH847 to name a couple) run the stator as required to charge the system. Shunt regulators run the stator at 100% output all the time and dump the excess wattage to ground via short circuiting. How stupid is that??

Let me put out some numbers here and Hopefully help increase the understanding of what's going on.

The Shunt regulators run the stator at 100% output. The output either goes to make up the losses in the electrical system or it's shunted to ground. That means the stator is putting out 14.5 volts @ a maximum of 35 amps? all the time. That's 507 watts of energy. 507 wats = 1732 BTU's of heat. That heat has to be taken away from the stator which is done by the engine oil. If the engine oil doesn't completely saturate the stator and remove the heat and allows the stator to get over 400 F, the varnish on the stator wires will burn off becoming carbon and short the stator

Series regulators open and close the feed from the stator to meet the demands of the electrical system. When you start the bike, that initial draw on the battery from the starter needs to be replenished and the charging system goes ahead and tops up the battery. Then things relax and the running electrical draw only needs to be met. The series regulator only demands what it needs from the stator, so if the running requirements say during the daytime with no lights running is maybe 10-12 amps, them the stator is asked for 14.5 volts at 12 amps = 174 watts which equates to 593 BTU's.
So, if you were a stator, would you like to run at 1732 BTU all the time or would you like to run at 1732 btu for a couple of minutes and then at 593 btu for the remainder of the time?? No brainer here right??
Last edit: 4 years 2 months ago by Kawboy.
The following user(s) said Thank You: biltonjim, Neville

Please Log in or Create an account to join the conversation.

More
4 years 2 months ago #27958 by Bar
Replied by Bar on topic Second Alternator???
I had the same though regarding the second alternator
I have 84 voyager, I understand the use of the extra charging system in this case when you running a full touring bike with the extra draw, however, I don’t see the need for that on the KZ.
All bikes from this era use pretty much the same electrical system and I do not remember any of them using 2 stators/ charging systems.
Since I will be running LED front and rear light and re-wired the bike with M-Unit I believe I will be good with one.
After I put the bike back together, I may do some testing and run only the main

1984 Kawasaki Voyager
2002 Honda CBR954

Please Log in or Create an account to join the conversation.

  • rdurost
  • Topic Author
  • Offline
  • Elite Member
  • Elite Member
More
4 years 2 months ago #27967 by rdurost
Replied by rdurost on topic Second Alternator???
Hey Kawboy-

I didn't quite follow your first sentence. Would you care to elaborate a bit?

"I wouldn't be too hasty getting rid of your aux. alternator until you're satisfied that you have something that works. The 82's were very unique. The Main alternator was only used on the 82. I'm thinking the 82 was a tried model to prove that dual alternators could work. The 84-89 had a larger Main Alt with an Aux alternator."

So, are you saying that I shouldn't be removing anything until I'm sure it all works? What do you mean by the Main alternator in '82 vs. the Main alternator in 84-89?

I'll take a look at the factory manual to find the alternator outputs of various years, but as of now I can't imagine exceeding the output capabilities of the original system unless it was grossly undersized, plus I intend to use a "real" regulator instead of a shunt to ground, so average temperatures should be significantly lower.

Please Log in or Create an account to join the conversation.

More
4 years 2 months ago #27969 by Kawboy
Replied by Kawboy on topic Second Alternator???
Over the past several weeks, I haven't been able to find the output specs for any of the stators or regulators on the stock bikes. I was just warning you that the 82's were unique. The Main stator for the 82 was only used on the 82. There was a main stator for the 79-81's and a main stator for the 83-89's and an aux. stator for the 82-89's. I wouldn't be giving up the aux stator on your 82 until you have convinced yourself that running the Main stator only on your 82 will do the job.
The regulators are another unique feature. The Main regulator is a Master and dictates the output of the Aux regulator via a trigger wire between the 2 regulators as I remember it.
I'm all in favor of dumping the Aux stator, rotor and reg if you don't need it and going with the LED's will make a difference but only in regards to driving lights. Got to figure that a standard headlight bulb is 55 watts which is 1/6 of the charging circuit output. LED headlight will bring that down to 10 watts??

Please Log in or Create an account to join the conversation.

  • rdurost
  • Topic Author
  • Offline
  • Elite Member
  • Elite Member
More
4 years 2 months ago #27970 by rdurost
Replied by rdurost on topic Second Alternator???
Gotcha. I was hoping to retain the stock halogen headlight, because I've heard lots of negative things about the aim on LED replacements.

Any idea what the ignition system would draw at maximum? I would assume a fraction of maximum alternator output. I would like to mount LED driving lights, because in my area we have a plague of deer, especially at sunset. Other than that, nothing but moderately high-output horns. And I don't really plan to be caught out after dark in any case.

Please Log in or Create an account to join the conversation.

Time to create page: 0.125 seconds
Powered by Kunena Forum