dear all,
maybe a weird question
i just purchased a 2011 accord sedan,
there seems to be something fishy going on in my car,
whenever im driving at night and i have lights on and a/c on. when the a/c compressor kicks in, my headlights dim noticeably.
I contacted a friend thats a mechanic; he said the battery in the car might be damaged. so i open my hood looked at the battery and noticed that the battery case is much larger then the actual battery put in it.
so i'm thinking the car dealer took out the original battery, installed a smaller one, and probably sold the original one for profit.

i went to the dealer and they told me the battery was original, tested that battery and alternator, both Passed the computer test, this i saw myself. but still im convinced the battery is too small and can't actually handle the electrical load required by the car, and as a result the lights dim.

can someone confirm honda accords are delivered now with "smaller then it's casings" battery's?

 

The original battery is smaller than battery support area. Battery seems to be a good battery. I'm into 4th year on my 07 Accord.

The dimming you notice is reported by many. It is a feature of the load detection circuit, which disables the alternator when battery charge is good. This reduces alternator load and increases gas mileage marginally.

If you want to see the action, purchase a Battery Monitor from Walmart ($15). I have one and have used it several times to verify when a battery has failed. You will be able to see when Load Detector circuit disables the alternator. Battery voltage will drop to around 12V.

good luck

 

OTOH, if the idle RPM drops significantly when AC clutch engages, then you might have trouble with the idle-control system.

On 2011 that system is a bit different from what I know, but then your car is probably still under warranty.