Hissing noise after jumping dead battery

The hissing and smoke could likely have been too much pressure in the AC system and some of it vented. Look on the passenger side fender for the round receiver / drier to see if there is an oil stain near the pressure relief valve. The car can be driven if that's what it is, but the cause will need to be found. Usually it's due to a restriction in one of the hoses, or someone was recharging the system and over-charged it with too much refrigerant. That should not be related to the dead battery.

Thanks for the quick response caradiodoc. I didn't see any staining anywhere, the engine is still fairly pristine. I'm not sure I properly identified the valve vent, however. I also had the AC off when I started the car (if that would make any difference).

I did just discover that the battery is dead again (I just jumped it and let it charge for a while earlier today). Not even the fob works to lock the doors. Totally drained. We had a similar problem 11 months ago when the battery would not hold a charge. The dealer blamed the battery and gave us a new one. Worked fine for 10 months, until now.

Sounds more like an electrical problem now that we are having charging problems again in such a young car. Almost like there is a short draining the battery...that loud venting noise is new this time, though.

Does the AC seem to work properly? If so, that hissing might not have been refrigerant venting. Perhaps the serpentine belt was slipping and smoking. That slipping can sound like a hiss.

I think the place to start is with the draining battery. There has to be quite a draw on it to go dead overnight. Testing for that draw has become very complicated in the last 10 -15 years because of all of the computers on the cars. Some of them take up to 20 minutes to go to "sleep" mode after stopping the engine. During that time they can draw over three amps. If something prevents a computer from going to sleep it will continue to draw that high current until the battery is dead. That could be in as little as four to six hours.

Your mechanic will have to set the car up to be ready to make measurements after the computers have gone to sleep. That is complicated by the fact that nothing can be disconnected from the battery, otherwise the time-out process will start all over again.

Imontgomery, did you ever find out what the underlying problem was? I just had almost the exact same issue with my 2010 CRV, except the hissing and smoke happened yesterday evening, and my battery was dead this morning. I just had the battery replaced at the dealership, but from the sounds of it, I'll probably be back for a new one in less that a year.

Any additional info would be appreciated!!!

Just have had the exact same problem. The battery died, though i can not recall leaving anything on. jump started, idled for 3-4 minutes, AC was on. drove a cuople of miles, stopped and idled for 3-4 minutes again. Then very loud hissing noise came in, white/blue-ish smoke came out from the passenger side of the hood. Also, it somewhat smelled of rubber burning. turned it off, checked if anything visibly was damaged. did nor find any. started, idled for 3 minutes and the exact same thing repeated. no idea what is wrong. having it towed. will update.

It turned out to be :
1. Busted AC relay which stayed in ON position thus draining the battery. It costs less than $10 and is easy to fix: simply open the fuse (relay) box and change.

2. Smoke was from AC pressure relief valve which apparently could not handle the pressure build up (assuming that was due to the AC running at all times). The valve costs ~ $ (40-60). But, I could not find a good link on changing the valve.