DC wiring

I reckon having at least the marker lights on with the engine stopped if you fall in the dark is a good thing, but you are right about the battery going flat if you accidentally leave somthing on. In face the older bergs have a power relay that pulls in with the ignition switch. You can turn all the lights off with the key still on and the power going through the relay coil will still flatten the battery over time. Not a great design!

The idea of putting a diode in series with the battery and drawing the lighting power upstream of the diode has a problem but can be made to work. The problem is that you must always drop at least 0.7V across a silicon diode when passing current through it. A big one of about 10 or 20 amps rating will typically drop 1.1V at full current. That is, in your proposition, the battery will see the regulator voltage MINUS the diode drop. The batteries in these things need accurate voltage regulation to work well & bergs tend to undercharge the battery at the best of times.(People usually have to charge the battery after each ride!) The diode would make it almost not charge at all with a standard regulator.

You might be able to modify the regulator to bump up its output voltage to allow for the diode drop, but it might not be possible to get the later regulators apart. I have done this to my older model for a different reason & it seems to work OK, but then my bike gets so little use I still have to use a charger anyway.

For what you speak of I'd suggest running the headlight only off AC and keep the rest of the system DC off the battery, however this might not be what you are after.

Bundy Bear:

Would going to full D.C. power solve the problem of the battery undercharging at least as long as the lights were off?

From the tests I did on my '98 e-start bike the charging system has several design flaws, the main one being the regulator is not up to the job. I think it looks like a left-over from Briggs & Stratton mowers. It is only capable of half-wave regulation but is connected up full-wave?? I would have thought the older ones would eventually overcharge the battery if no power is being drawn from the system, however this does not appear to be what happens??

The mods I did at least seem to hold the battery voltage at a fairly constant 14.1 to 14.2V with the engine running. I'm not sure whether this still keeps the battery fully charged withy regular use but.

husabutt said:

Bundy Bear:

Would going to full D.C. power solve the problem of the battery undercharging at least as long as the lights were off?

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The guy who share the garage with me has done this. Converted to full DC on his 450 -04. He replaced the -04 regulator with a -03 regulator and the battery seems to be better charged. Now the bikes jumps alive a lot easier and the starter spins much faster.

If you have left the lights on, there are other possibilities to start the bike than the button.

Did he modify the stator as reccomended by Trail Tech?

husabutt said:

Did he modify the stator as reccomended by Trail Tech?

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Yes, but the first time it didn't worked very well. I think he needed to isolate the regulator and after that it worked very well. When you go from half/full wave system or AC/DC system there could be problem with the ground points.