This is an odd one. I went out this morning, scraped the ice off the windows, and discovered the battery was so dead it wouldn't even light up the interior LEDs. I tested it last week, and it was in great condition. The obvious cause would be something turned on overnight, but the headlights are the only things that turn on when the car is turned off, and they weren't on. I connected a battery charger, and the interior lights came on, so it isn't something major.

 

maybe someone moved the dome light to the ON position? not sure, but nothing surprises me any more with this gen Fit mang. hope its nothing.

 

You may never really discover what happened.
My suspicion would be dome light(s).

It's kind of sad that the Fit's battery is so small that it can be drained so severely so quickly.

I also hope that it's actually something as simple as dome lights being left on, otherwise you're left trying to track down an unknown parasitic drain. Sometimes not easy.

 

Yes, it probably was "an unknown parasitic drain." The interior lights are all LEDs, so they would take hardly anything from the battery, and I would have seen them lit up at night. I bought a new battery at NAPA ($120), and by the time I got home, I could start the car. I'm going to let both batteries charge completely and then leave the original in place, and carry the new one as a backup for a while. There is only one battery available for the Fit, the 151R, 330 CCA. With other cars, I was able to buy a more powerful battery.

I've owned a couple of dozen cars over the years, and nothing has been as much trouble as these two Fits. My son has spent $650 because the warning lights - Check Engine, etc - came on, and they're still on

 

People have been able to use 51R batteries in their cars. Some have had to trim the battery tray but other than that everything else was good. I'll probably be sourcing a 51R soon as the last cold weather day, the car sounded like it was struggling to start.

Till then I bought this and leave it in the car.

 

Yeah, I noticed there is a bit of room left in the battery tray. I'll get the 51R next time. Thanks for that.

 

Yes the 51R is a better replacement option because it has around a 500 amp cold crank rating vs the 330 of the smaller OEM 151R battery. A bit of a tight fit and as 2Rismo2 has mentioned the battery tray might have to be modified, but well worth it.

 

I'm not surprised that Honda made the battery tray larger than it has to be, but not large enough to hold the next largest battery.

I'll let the car sit today and see if it starts tomorrow.

 

silverEX- how's your battery situation today? did you figure out what drained it?

 

I was fine this morning, with lots of volts and CCA. It started about half a dozen times as I drove around today. I have no idea what drained the battery, but I'm carrying the new battery with me for a while.