No battery

I would really like to ditch the battery do kick only, but I want to run the dyna s ignition.

I cant find any info on battery delete. Any good links or pointers?

What is the output of the stock generator, and what does the dyna s + coils draw?



Thanks

check with Lou,im sure he'll be along shortly

notaduc wrote:

I would really like to ditch the battery do kick only, but I want to run the dyna s ignition.

I cant find any info on battery delete. Any good links or pointers?

What is the output of the stock generator, and what does the dyna s + coils draw?

Thanks

Including information about bike year and model may elicit better responses. And it's easy to put in your signature where it will automatically appear in posted messages.
When done, the signature information appears in all posts, past and future. And may be changed as often as desired.

Here's how to do it:
Click here > kzrider.com/index.php?option=com_kunena&...d=8&id=382004#382317

Good Fortune!

It's possible on some KZ's, but not others.

What bike, and year?

is a 1980 KZ1000 G1, but with carbs.

Looking at the parts diagram shows it is possible. (It has a permanent magnet alternator.)

It will run without a battery, (using a capacitor instead), but the question is, can it be kicked over fast enough to actually start.

To test it, here's what you need to do.

Get a 5000 to 6000 micro-farad (uF), 50-volt capacitor, preferrably with screw leads. Wire it in place of the battery.

Then disable all of the lights and gauges so they are using no power at all.... to be continued

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I'll have to finish later, work just got busy.

Can't wait to hear the rest

Sorry, my internet was out when I got home. It's back now.

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I should first mention : The bike has to be able to start on one kick reliably in order for this to work, so you will want to make sure it can do that before removing the battery.

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Next,... The battery, even when there is no regulator, acts somewhat like a regulator itself, so it can limit small surges of voltages. The capacitor cannot do that. If the bike is turned off, but is allowed to coast in gear, the alternator is still making power but the regulator stops working. This puts a large surge of un-regulated power into the system. A battery can handle it and limit it, but a capcitor may pop or you may burn out all of the lights. To prevent this, a little bit of re-wiring needs to happen on the regulator/rectifier.

The brown wire on the reg/rec needs to be disconnected from the harness, then tied directly to the output wire on the reg/rec (which will be directly wired to the + on the capacitor). This way the regulator is working anytime there is alternator power.

You don't have to do this just for the test, but just make sure the bike is not revved before it is shut off, and is shut off with the kill switch.

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Regarding ignition.

The capacitor stores a charge, but is very different from a battery. It goes from zero charge to fully charged in a moment, and discharges just as quickly. So in one kick, the alternator has to produce enough energy to charge the cap and fire the ignition. There is not much extra which is why the lights need to be off during sarting.

The Dyna S is not a good match for a batteryless bike. It wastes way too much electric power during startup.

The most efficient ignition would be the stock electronic ignition from about 1980 or 1981. Even better would be the stock electronic ignition with an HEI igniter substitued for the factory igniter. Here is a link to the details:
home.comcast.net/~loudgpz/GPZweb/Ignition/GPZgmHEImod.html
The HEI is more efficient because it will not turn the spark coil on until just before it is needed. The factory igiter does this also, but the HEI is slightly better.

If your test works out, and you plan to rewire the bike for simplicity, I can draw up a schematic and even give you a trick circuit that will automatically turn the lights off when the bike is shut off. (I made that on my bike because I would forget to turn the lights off while starting which prevents it from starting.)

notaduc wrote:

What is the output of the stock generator, and what does the dyna s + coils draw?

The output of the stock generator varies with RPM, but is sufficient to power a batteryless bike as long as you are not running too much extra. I actually run two 60watt halogens on my 81 550 with no battery. At a low idle, you can see the lights flicker (due to ignition pulsing) but at even a slight rev, they are both immediately bright.

The current draw on an ignition also varies greatly depending on conditions. But here is a theoretical approximation.

Let's take idle conditions at about 12v. The Dyna S must use 3-ohm coils or higher. Let's assume we have perfect 3-ohm coils. The Dyna S has somewhere near 360 degrees of dwell. Let's assume there is about a 2 volt drop from coil to ground across the ignition. (Typically it is somewhere between 1 and 2 depending on current and heat.)
That means you have two coils running continuosly at 10v. That's about 6.7A. (This is just the theoretical value for idealized conditions, real values are subject to a lot of variables like coil temp, coil resistance, which will even be different for different age coils.)

Now let's look at the HEI with stock pickups and coils. It uses coils spec'd around 2.3 ohms, so we'll use that value. The dwell, as I've measure it, was around 80 degrees near idle. Let's also assume the same 2v drop. This ignition uses about 1.9A.

6.7A for Dyna S versus 1.9A for HEI under idealized conditions near idle. (Every bike will yield a different measured value because there are so many factors that affect the final value.)

At higher RPMs the difference will be less, but more importantly, at startup, the difference is much greater, and that's the important thing when going batteryless.

Amazing responces, Thank you sir.

If it seems that you can't quite get the speed necessary on a kick to start it with the capacitor, another option would be to use a tiny scooter battery. I've done that on a few bikes with success. (The 77-kz650 and most kz400's have to use a battery.)

That would work fine with the Dyna S (provided the charging system is working normal), and it would allow for starts with a slightly slower kicking speed.

The 50cc Honda Spree scooter batery is cheap and plentiful.

Hey,

Could I see this schematic you mentioned at the end of your post?