hello everyone i recently bought a 2011 fit and i love it. but i have noticed that when it sit a idle the lights dim. any ideas why

 

We've got tiny batteries and the alternator isn't churning out top power at bottom speed. Don't worry about it.

 

Or get HID's. Since they use a lot less wattage (35 vs. 55) it should be less drain on the battery.

 

^^ wat fit charlie said. my 08 did it, my 09 and 12 does it.

 

i was thinking about putting hids in. i have been looking around and have noticed that the factory battery is a special order. i guess you can put a oddessey battery in its place with some modification, have you guys seen it done

 

Do a Fit Freak search for 51R

 

im just worried about the warranty if i switch to the 51R

 

Battery doesn't void warranty. You can always throw the old one back in.

 

The size of the battery doesn't affect whether your lights dim at idle or not. Whether a battery has 60 or 30 amp-hours storage capacity, the few moments at idle will not have used this.

A drop in voltage will cause the lights to dim.

The car's charging system, an alternator, is voltage regulated. Below a certain RPM however it can't maintain voltage (the load is greater than the alternator's ability to create electricity at that speed) and the battery starts to drain. This drop in voltage may be 2+ volts (decreases from approximately 14 to 12 volts). A 15% drop in voltage (and current is a function of voltage and resistance) will result in a 15% drop in light level.

However, the Fit (and Hondas in general) also have an electrical load sensor that controls alternator output and signals the ECU to increase RPM. When you turn on the lights at idle, you should notice a slight (200RPM?) increase in idle speed.

I don't notice the lights dim in mine when I'm at idle, or increase brightness when RPMs go up. I could be blind (other drivers beware). The only time I notice this is when the A/C engages; this puts a high load on the electrical system as it engages an electromagnetic clutch on the compressor, and runs the two fans on the radiator/evaporator. Even this is momentary as the engine speed and alternator output adjusts.

I'd have your battery and charging system checked, but it's entirely normal for some fluctuation in light output.

Wedging a larger battery in there won't help.

HIDs might, but it depends on their driver modules and how well they regulate voltage (they produce a very high voltage from the car's low 12-14 volts).

Honda could spend more money and put voltage regulators on the headlights to maintain brightness levels even if the alternator system voltage drops, but it's really not a big selling point on an economy car.