Voltage output with Sparx alternator

Hi all. Just installed the Sparx alternator and a new regulator. Bike runs great, but generator light remains on all the time. Is this normal? The alternator is putting out 14.6 V and the battery (when the bike's not running) puts out about 11.3V.

Your alternator is fine. Your battery is not. 11.3 volts from an unloaded battery is much too low. A fully charged battery will show 12.5 volts or higher, and only dip slightly when you turn the lights on.

radiofun said:

Hi all. Just installed the Sparx alternator and a new regulator. Bike runs great, but generator light remains on all the time. Is this normal?

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In the original system, a green/yellow wire connected the assimilator to one of the stator output wires . Has that G/Y assimilator wire been left disconnected? However, I believe the output from the three-phase may burn out the standard assimilator-so perhaps replace it with a low voltage (LVS) unit if you want to keep the charge warning light?

http://www.aoservices.co.uk/data/lvs.htm

rick in seattle said:

Your alternator is fine. Your battery is not. 11.3 volts from an unloaded battery is much too low. A fully charged battery will show 12.5 volts or higher, and only dip slightly when you turn the lights on.

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yep, full charge is about 13.2 volts with no load (6 cells x 2.2 volts each for lead/acid batteries)...might be worth charging the battery with an external charger to see if it will take and hold a charge

bluto said:

rick in seattle said:

Your alternator is fine. Your battery is not. 11.3 volts from an unloaded battery is much too low. A fully charged battery will show 12.5 volts or higher, and only dip slightly when you turn the lights on.

Click to expand...

yep, full charge is about 13.2 volts with no load (6 cells x 2.2 volts each for lead/acid batteries)...might be worth charging the battery with an external charger to see if it will take and hold a charge

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This first.

thanks all. I will charge the battery with the Tender and see if it holds a charge.

Radio,

After you confirm that the unloaded battery will charge to 12.5 v or higher, place it in the bike and turn the lights on. Still 12.5 v? If the voltage drops to below 12v in the first 60 seconds of the test, replace the battery. The lifetime of a 100-buck motorcycle battery is very short: two years or so.

Here is another perspective.
You have changed you stator because your old one failed, we can assume? And we should assume that you are reading stator voltage at the battery terminals? I think (it has been awhile since I have had one) the the assimilator fails in the closed position (light on)?
That being said, your battery has been stressed and has more than likely lost some, if not all, of its internal memory. This is now a weak link in your system. By what i have read so far, this battery is failing. Even if only one or to seasons old, it does not matter.

You can charge it with a trickle charger but this is not what it needs. You need a good charger to, hopefully, bring this back to life. Then, take it to the auto parts store and have it tested. Just putting it back in the bike and turning on the light is NOT all well and good, and will leave you with questions and perhaps stranded somewhere, where as a tool meant for this will leave you with definite answers.

Many of us profess to now all about batteries but there is one universal truth, a weak battery is soon to be dead, new stator or not.

Bottom line!
My advice is to bite a bullet and match that nice new charging system with a nice new battery and ride with confidence into the night.

A very easy procedure to check a battery is to charge it for about a day until it gets to 13.8-14.0VDC. Remove the charger and let it sit for 24 hours and check the voltage at normal room temperature. If the voltage is below 12.5VDC, it's pretty weak. A good battery will hold 12.7-12.8V easy. They usually fall off real fast, so if you're seeing less than 12.0VDC, it's shot. Sitting voltage on a battery is a very good indication of it's capacity. There are some instances where they can be rejuvenated, but unlikely, especially if they are over a year or 2.

Dave
69S

Another problem is when your stator (or regulator goes), it stresses your regulator (or stator). So when you replace the [insert either here}, you may also need to replace the [other].

This post not adapted to zener and xylophones and all those end-alphabet components as they frustrated me too much and I restarted my own alphabet with A for Alternator (and yes, a new R for regulator).

I have installed a sparx 3 phase alternator and regulator to my 71 fastback. I have been running the bike in for the past 500 miles, in fact I completed it today. The charging system is working as advertised as I run the high beam light with a halogen bulb at all times. I have encounterd zero problems so far. To address the warning light assimilator, I spliced into one of the yellow output lines the green / yellow wire from the assimilator. The warning light goes out at start up and again I have encounterd no problems in 500 miles. Hope this is helpful. Craig

Glad you got the warning light working Champ. With a little more pondering about this I've concluded that my warning indicator light remains on all the time because the yellow/green wire to the assimilator is no longer connected to anything. Imagine that! I guess the questions are 1) is it important to have the warning light still functional, and if so, 2) does it matter which wire from the new regulator is connected to the green/yellow wire to the assimilator? Note: the new regulator has 3 yellow wires connected to the 3 alternator wires, a black hot wire, and a red ground wire.

radiofun said:

is it important to have the warning light still functional

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It's really a matter of choice-but it doesnt affect output if it isn't connected.

radiofun said:

does it matter which wire from the new regulator is connected to the green/yellow wire to the assimilator? Note: the new regulator has 3 yellow wires connected to the 3 alternator wires, a black hot wire, and a red ground wire.

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Connect the green/yellow to one of the three alternator stator to yellow box wires, it shouldn't matter which one.

radiofun said:

Glad you got the warning light working Champ. With a little more pondering about this I've concluded that my warning indicator light remains on all the time because the yellow/green wire to the assimilator is no longer connected to anything. Imagine that! I guess the questions are 1) is it important to have the warning light still functional, and if so, 2) does it matter which wire from the new regulator is connected to the green/yellow wire to the assimilator? Note: the new regulator has 3 yellow wires connected to the 3 alternator wires, a black hot wire, and a red ground wire.

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The 3 yellow wires can go right to the 3 wire of the three phase stator. The red and black right to the battery. Anything in the middle, Bye Bye.

Thanks.

I fitted the Sparx 3 phase alternator and regulator to my Commando 850 1500 miles ago. I had problems initially as the rotor was too tight and I had to have it honed. When it was finally fitted, I was happy with it as I managed to wire in the original assimilator and the charging light went out when the engine was running. This spring when I came to use the bike after the winter layoff, the yellow charging light only glows all the time now and I think the writer of one of the above posts is correct and that the 3 phase alternator burns it out. As a charging light is pretty important, I fitted a Battery Status Monitor (BSM, from Al Osborne - see above web link for aoservices). It is a LED set up which changes colour depending on the voltage. At first I thought great - it went the required green at 2000rpm with the headlights on but when I took it out on the road, it started flashing red at 2500-3000rpm showing overcharging. I fitted NGK 5000ohm plug caps as recommended when I fitted the alternator. Has anyone had any similar problems, and if so, how did you fix it?

Rob_in_scotland said:

I fitted a Battery Status Monitor (BSM, from Al Osborne - see above web link for aoservices). It is a LED set up which changes colour depending on the voltage. At first I thought great - it went the required green at 2000rpm with the headlights on but when I took it out on the road, it started flashing red at 2500-3000rpm showing overcharging.

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Did you double-check the voltage with a meter?

Not yet. Thanks for the suggestion, that will be today's job.

Rob_in_scotland said:

Not yet. Thanks for the suggestion, that will be today's job.

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My brother told me there was an issue with Sparx regulators. They are sensitive to RF and so you need resistors (either plugs, caps or wires) or you may not get the charging you are expecting. Be sure to check your ignition.

Did you double-check the voltage with a meter?[/quote]

Just checked the voltage. Battery gives 13 volts without engine running and voltage goes up to 16 volts at above 2500 rpm. Multimeter is fairly old so I am going to borrow a better one and double check to get an accurate reading as I can't believe my old battery holds charge that well. Also neighbours getting upset as they are eating their tea and listening to my bike doing 4000 rpm.

My brother told me there was an issue with Sparx regulators. They are sensitive to RF and so you need resistors (either plugs, caps or wires) or you may not get the charging you are expecting. Be sure to check your ignition.[/quote]

Thanks for that idea but when I bought the set up from the UK distributor, I also got 5000 ohm resistance plug caps as recommended.