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Posted by mm on July 18, 2006, 6:05 pm
>Say What?? alert.
>Let's get the apples in one box and the oranges in another box. Don't
>mix 'em.
>Looking at the extremes and assuming some monotonic interpolation
>between 'em...
>
>A battery can be either good or bad.
>A good battery can be either charged or discharged.
>
>If your battery is good but just discharged, it will hold the voltage
>down when the generator tries to stuff current into it. Life is good.
>
>The problem is with a BAD battery.
I don't know for sure, but I'm going to assume that after 31 years
without riding, the battery is BAD. :)
>The primary failure mode is
>sulphation. That causes the internal resistance of the battery go to
>up. When the generator tries to stuff current into it, it can't hold
>the voltage down.
>
>Now let's look at the charging system.
>Older bikes had no regulation. They used the battery to absorb all the
>excess current from the generator. But the battery was tiny and
>wouldn't last long at that. The whole system depended on a delicate
>balance between the generator output and the lighting load. My old 1972
>Yamaha used the leakage inductance of the magneto to give first order
>compensation as the engine speed increased.
>
>My '75 Honda CB125S uses the tiny battery as a "regulator". The battery
>lasts about half a season before it's resistance goes up...the headlight
>burns out...then the other lights burn out very quickly. At
>$35/headlight, that gets old rather quickly. Headlights aren't
>particularly more vulnerable...they just cost more.
That's exactly what I needed to know. I'll get the battery first
thing.
> I put a shunt
>regulator to absorb the excess current and limit the voltage. Haven't
>burned out a headlight since.
I would like to do that if you give me more details.
> Batteries last forever.
>
>Newer bikes have real alternators and regulators just like a car. But I
>still wouldn't run one with a bad battery...not to be confused with a
>discharged good battery. They also changed the way the ignition worked.
>Old bikes sparked off the magneto. Newer use CD-style ignition that
>requires some serious peak battery current.
>
>Biggest question is where your bike lies during that changeover period.
>Be safe and put in a good battery. I won't recommend the way I do it
>cause I don't want your heirs to sue me.
I don't have any heirs, and I'm a newbie to bikes but with a lot of
experience on cars. Are you talking about using an old car's voltage
regulator, or some transistorized thing? That I buy or make?
>mike
>
>Jack Hunt wrote:
>>
>>
>>>I don't know why this would be true. I would think it isn't. And I
>>>wouldn't think the headlight is more vulnerable than other lights, or
>>>that Hondas are different from other makes. But the guy's webpage is
>>>pretty good and he doesn't seem crazy.
>>
>>
>> Bullshit alert. You need to delete that link now. Whoever wrote that is *so*
>> full of shit.
>>
>> You can't get it running without a battery. You're not going to hurt the
>> headlight running it with a low battery. The stuff he writes about running
the
>> engine with a mixture of kerosene and oil is just scary.
>>
>> He even contradicts himself. "Disconnect the headlight so you don't hurt it
>> with a low battery, but install a new battery before you start it." He
sounds
>> like one of those morons who pull the battery cable off with the engine
running
>> to "test the charging system". Now that will blow a bulb. Running with a low
>> battery won't.
>>
>>
>>
>>
>> --
>> Jack
>>
>> Posted Via Usenet.com Premium Usenet Newsgroup Services
>> ----------------------------------------------------------
>> ** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
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>> http://www.usenet.com
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