Topic: What does and increased Electrical load do to a CB550

[cb550inct]

I have read several posts here about how a cb 550 ha an inept electrical system.

If you drawing too much from the electrical system what does it do to your bike?
Im guessing it would drain the battery, but would it effect perfomance of the engine

[Gordon]

If you're drawing more power than the charging system can keep up with, it will deplete the battery.  Once the battery drops low enough it will start effecting the ignition system, causing a weaker and weaker spark until the engine eventually dies. 

[cb550inct]

good to know....im not having that happen. Iam insatlling new carb gaskets and cleaning them this weekend. Lately i fell a hesitation at low rpm in first and second gear. Im guesssing its a tuning issue i feel im running too rich. I plan on turning my needle back one notch.

I want to rule out electrical as a problem, my problem sound like a carb issue

[Duanob]

All things being in working order your charging system should be more than adequate for your bike as it came form the factory. I've installed a DYNA-S ignition, DYNA 5 ohm coils, and a H4 headlight and my charging system does fine but I had to go through and fix a lot of bad and corroded wiring to maintain a charge to the battery. According to my battery bug I get high 13v charging at hiway speeds (> 2500 rpms) and 12 v at idle. 

[crazydog]

Your issue sounds more like tuning.  I'd start there.

You can get good voltage, but not enough amperage.   I've added a DynaS and 4 corner marker lights.  When I ride in town with my lights on I have noticed that after several days my battery dies without being put on a charger.  Don't seem to have problems when I run on the highway often.  My next change is going to be switching to 5 ohm coils.  The cheapest and easiest way to measure the running amperage is to use a high voltage shunt.  Basically a piece of measured 18g battery wire temporarily placed in line of the - terminal and the lead from the bike.  Using a volt meter set to mV you can get an idea of if you are charging or discharging the battery the mV=Amps.  You can get more complete instructions if you Google it.

[Bodi]

Good old Ohm's law has the answer for this.
The basic equation E=IR can be juggled to become P=E²/R meaning power (watts)= volts squared divided by resistance (ohms).
That means your bike's load power increases with the square of the system voltage, an "exponential" increase.
Your alternator can only make a set maximum power: incidentally this power output decreases as the system voltage is reduced - the lower voltage makes less magnetic field in the field coil but this reduction is linear, not exponential.
So if your alternator has a maximum power of 150W (a guess) and your electrical system load at 14.5V is 140W, your voltage regulator will maintain 14.5V and your battery will be fully charged after a nice highway ride.
If your system electrical load at 14.5V is 180W, you don't sputter to a stop during your highway ride. With that load the alternator's 140W will only make 12.6V or so at full output: enough to light the lights and fire the ignition, but not to charge the battery. At highway RPM you'll get a bit of a charge, at idle the battery will discharge as usual (just faster than "stock"). You won't be using electric start much, and your battery won't last many years. If you use a battery tender or similar you can ride every day and plug it in at night without any trouble, but skip the charging and you'll have low voltage issues soon - especially in city riding.

[dave500]

mis fire under load is the first sign on an otherwise perfect ignition your battery is getting low,,i run a 55/60 h4 and boyer and have no trouble,i dont tootle around town much though which can really lower the charge rate especially if you run the headlight,i have an analoug volt meter and shut off the head light if im in traffic.

[Duanob]

If you're having charging issues I swear by this guy's diagnostics:

http://www.oregonmotorcycleparts.com/FAQ.html


(what the hell is going on with posting links???)

I had some serious charging issues that left me and my wife stuck on the side of the road. I swore up and down it must have been the alt or the rectifier. After using the diagnostics method the problem kept coming back to bad wiring. Sure enough I took the electrical panel off and found three main wires burnt to a crisp along with the connectors. Even after I replaced the main battery cables. I also found the rectifier to be fairly new as the connectors ages and shape didn't match up. After replacing the wires completely by buying this guys connectors and blocks my charging system is adequate. My battery doesn't lose juice anymore. I figure there might be more bad wiring but for now I'm enjoying riding to work and around town without having to charge my battery every week or worry about breaking down. My battery bug is sure nice to know what's going on with the charging system.