Cooling Fan

[JQL]

Since I put the voltmeter on the bike I've noticed that when the cooling fan comes on there's, initially, a hell of a voltage drop before it stabilises again.

I know my battery is getting beyond it's service life (I'll replace it in October when the temperatures start to drop significantly), but has anyone else noticed the same?

 

[bicyclist]

Better trade it, quickly, on an FJR.

 

[moriniman2011]

Is that because the fan comes on mainly when the engine is idling and the alternator is not pumping out as much juice? Whenever it finally gets warm over the pond here I'll see what happens on mine!!

 

[charlie b]

Not unusual at all for electric motors like that. Startup currents for motors without a capacitor start can be 10 times as much as the running current.

 

[moriniman2011]

Actually warm today in the UK (well my bit anyway!) so off for a bimble round a few lanes and stop for a little idle to allow fan to come on. Voltage does drop to 12.9 ish for a second or two and then rapidly recovers to 13.9 as normal (have the foglights on). As Charlie B says this is normal - try starting a big mains cutter on a circuit with a trip rating close to the motor rating.........