I have a 2009 Honda Fit and I religiously crank it up for at least 15 minutes every 2 days, specifically to keep the (tiny) battery topped off. Recently, it did not crank one morning (typical low battery signs), so I suspected the battery was going bad and got a brand new one. Even with the new battery, I maintained my 2 day crank up routine. About 2 weeks later, it does not crank once again. Measured the battery with a multimeter and it's at 11.3V. Since this is a fresh battery, my best guess is that there is a parasitic electrical load happening even when the car is completely shut off.

So I put the multimeter in ammeter mode and disconnected the battery return, then completed the circuit with the ammeter to see how much it was pulling (while car was fully off and no key in ignition). I witnessed the following:

Right when I completed the circuit with the ammeter, it showed about 330 mA for about 5 seconds, then dropped down to 175mA. At 175mA, if the doors were locked, it would drop to 11mA after a few seconds. if the doors were unlocked or open, it would remain at 175mA for about 10 minutes then drop down to 11 mA.

I did a fuse-pull walk while the car was in the 175 mA mode to see if I could isolate the parasitic load circuit. None of the tiny fuses made any difference other than fuse #1. When I plugged fuse #1 back in, it just restarted the cycle at 330mA.

Does anyone know what an acceptable current draw is on this car? Does my description of the current draw cycles seem normal? Any other ideas?

 

Letting the car run a idle twice per day may really not be good for the car, nor the battery. For the alternator to really charge the battery, you need to drive the car.

Best way to do so would be to use an intelligent battery charger and let it plugged in.

EDIT: Also suggest going to the 51R battery, which is bigger. Many threads on here on how to do it.

 

I have fully charged the battery with an intelligent charger, and had the (1 month old ) battery tested, which was a pass. Even with the battery fully charged from an intelligent charger and then reconnected to the car, it drained down to 11.3V in only 2 days. I agree my charging method could be better, but I'd think the state of the alternator is irrelevant once the car is turned off (unless the alternator itself has become the parasitic drain).

I'm definitely down with getting a bigger battery if possible (always hated the tiny ones), but I still think there's a "new" problem with the car, because this never used to happen.

 

NO. dont get bigger battery. I have been starting my k24Turbo Fit with just 18Ah battery even after 4-5 days it cranks right up.
just do through leak down test. and if no cause found you can buy this cut off switch and just turn it off when parking car for long times.

 

So, wire the switch into the ground battery terminal? difficult to see in your photo

 

i have wired it into my +ve.

 

Yeah but if you use a kill switch to solve this problem, you'll lose the radio and any preselected stations. I wouldn't want to put up with the hassle of having to enter the code everytime I started the car. Plus having to reprogram the stations. I'd try to figure out what's causing the parasitic drain and solve the actual problem. It has to be something that's protected by a fuse so you should be able to find the problem with a multimeter. Yeah, it's a tediuos process but I don't know of any other way.

 

yes you are 100% right. This method is just a backup method. and not suited for a normal car. since mine is heavily modiefied from engine to radio. so it does not affect me atall. but saves me of hassle of battery drain since some time i use car after a month or may be two months apart.