Smoke from rear interior after acceleration

Yikes that's totally unacceptable to have smoke and we have not heard many smoke reports like that, I don't think. That vent (if on the passenger side) is the hybrid battery vent. There is a fan down there that can clog up and needs to be looked at once in a while. I would wonder if the orig owner had the hybrid batt replaced. Also the 12v batt is down there and could contribute. There is a vent to the outside there over the rear tire.

 

why don't you take apart everything in the back and take a look. Pull everything out as if you're going to get to the spare tire and the battery

 

Wow! I was shocked at the title of this thread! I've never heard of this before. Take a test drive with the technician at the dealer and drive up the hill that made the battery smoke. Did the previous owner replace the hybrid battery? If you don't have a lot of knowledge about your car, I wouldn't take everything apart. Good luck!

 

The plastic grille on the top right of the rear seat is an intake for cooling the hybrid battery and it's unlikely smoke came out of it. There are heat sensors in the battery cells, and mechanisms to shut down the hybrid system in case of overheat. That's good news--there probably isn't an issue with the main battery cells. It's possible the hybrid control shorted and burned without producing a lot of heat in the battery cells, but that likely would have blown a fuse and disabled the system. Inspecting the system would require special tools, safety precautions, and knowledge.

If the smoke may have come from the passenger side rear of the luggage compartment, that's where the 12V battery is. Since that was recently replaced, that's the more suspect area. But that battery does not see extra load (heat) when accelerating as the hybrid battery does, so if something shorted out on a climb it would have been coincidental. It's possible for a 12V short to produce enough energy to melt things, and that damage should be visible. There are a couple of large modules at the 12V battery terminal--I would inspect that area closely.

No check engine light? Did you happen to notice the state of charge of the hybrid battery on the dashboard display?

 

Read this thread. Battery Fire | PriusChat

You really should take the cover off the HV battery for an inspection.

Brad

 

Umm, that this directly coincided (twice) with high current being drawn from the HV battery would lead me to suspect the HV battery with probability close to 1. I can't rule it out just by saying there are a handful of temperature sensors scattered in measurement wells among the 28 battery modules. I would guess the smoke to be from local heating at a degraded connection somewhere on the current path (which could be any of the 56+ high-current connections in there, as they are all in series).

I would not recommend 'drive more and try to make it happen again' as a diagnostic approach. I would not be surprised if there's visible evidence, but it will only be visible with the battery cover off, which should be done by someone who knows the safety procedures and has the protective equipment to do it.

If the OP doesn't feel up to that task, I would urge getting the car posthaste to a shop that can do that and carefully inspect. If towing isn't an option, then driving very carefully, avoiding any high-current acceleration or braking.

-Chap

 

you need to take it to the dealer right away. if they say there's nothing wrong, insist they check it better, because something is very wrong.

 

welcome! keep us posted, all the best!

 

I could maybe understand oily smoke from engine compartment coming in through the vent over the rear tire, but you said smoke was electrical so that seems to point to rear compartment.

 

The hybrid battery can supply 100-120 amps under hard acceleration. Sounds like the very thorough inspection of the battery and surrounding area is needed.

 

Sounds like the battery is not in bad shape, just has a bad module. You can probably find someone to replace that module for you or you can do it yourself.

I don't think you need a new battery ecu, just the replacement module should fix it. If you want to replace the battery ecu, they can be purchase fairly cheap on the used market (about $50 or less)

 

There are 28 modules in the prius battery. Each module has 6 cells. Not everyone uses those terms properly.

Toyota's only approved method of fixing a bad battery cell/module/pack whatever, is to replace the entire battery. They don't have a service to replace only the bad module (1 of 28). You however can watch some youtube videos or find a local person that can replace that module for you.

 

if you just bought it, and plan to keep it for awhile, i would go with a new one. if you dump it down the road while the battery is still good, you might be better off to part it out.