2010 Corolla new battery dying

[Chrischick]

Just bought this car 2 wks car was fine. Wouldn't start yesterday so I charged Battery to 100%, car was dead 12 hours later. New Battery, alt good, the air bag pass seat light blinks as some as key is removed, is this normal?

[Catlover]

Can you clarify how old the car is please. Is it hybrid, petrol, diesel.

[Bernard Foy]

3 hours ago, Chrischick said:

Just bought this car 2 wks car was fine. Wouldn't start yesterday so I charged battery to 100%, car was dead 12 hours later. New battery, alt good, the air bag pass seat light blinks as some as key is removed, is this normal?

Can we assume it’s a Toyota Corolla 2010? But will need much more info than given.

[Chrischick]

Yes 2010 Carolla S model, Canadian built. When purchased no working radio, which as part of deal they would replace with factory 1. A week after is when the Battery was dead, I charged it to 100% and 12 hours later car was dead again. Nothing was left on in car radio, a/c or light of any kind. I noticed that pass seat belt light was flashing with car shut off. Dealership has car right now telling me it only needed a charge, new batt replaced prior to sale. Also said alt and batt tested good. I was a wholesale parts manager for 30 yrs, so not my first rodeo. Thanks any ideas/thoughts would be greatly appreciated. 

[Chrischick]

3 hours ago, Catlover said:

Can you clarify how old the car is please. Is it hybrid, petrol, diesel.

2010 Carolla S petrol. Car has a flashing pass a/bag light that blinks after removing key. Also car had no working radio, which dealership replaced than 1 wk later new Battery died, I charged it then 12 hrs later it was dead again. They say alt n batt good, I'm smart enough to know that something is drawing power. And did work as wholesale parts manager for 30 yrs.

[TonyHSD]

2 hours ago, Chrischick said:

2010 Carolla S petrol. Car has a flashing pass a/bag light that blinks after removing key. Also car had no working radio, which dealership replaced than 1 wk later new battery died, I charged it then 12 hrs later it was dead again. They say alt n batt good, I'm smart enough to know that something is drawing power. And did work as wholesale parts manager for 30 yrs.

Hi, 

indeed something is drawing power while the car not been used. I guess whoever installed the radio did eventually something wrong with your cables connections and your radio most likely draws constantly power and kills your Battery. Auto electrician or someone who knows that stuff can help you. 

[Mooly]

Lets put some numbers in...

If a 100% good and charged Battery is flat after just 12 hours then that suggests something is drawing 4 to 5 amps and so something somewhere is dissipating around 50 to 60 watts as heat. That level of current draw means something must be noticeably very warm or even hot somewhere. It is as much heat as a headlamp would generate.

 

 

[Chrischick]

Thanks everyone for your input. I am totally frustrated with the fact that the dealership that sold me car is not giving me a reason for why Battery has discharged, just saying it needed charge is not enough. Since No Return Policy, No Lemon law in Florida, I'm stuck with this car. 

[TonyHSD]

I think for safety reasons it is a good idea to take your car to auto electrician to have a look at it especially the area behind the radio as that heat mentioned above can trigger even a car fire. 

[Mooly]

You mention the alternator was  checked. Do you know if it was checked not just for charging correctly but also that no current flows back into the alternator when its not spinning. That is the only conceivable route I could think of that could sink that much current unnoticed.

A basic check is just to connect an ammeter in series with the Battery (engine OFF at all times) and see what the current draw is. It should be a few tens of milliamps at most.

  

[Red_Corolla]

6 hours ago, Mooly said:

You mention the alternator was  checked. Do you know if it was checked not just for charging correctly but also that no current flows back into the alternator when its not spinning. That is the only conceivable route I could think of that could sink that much current unnoticed.

A basic check is just to connect an ammeter in series with the battery (engine OFF at all times) and see what the current draw is. It should be a few tens of milliamps at most.

  

Little tip; multimeter fuses are expensive. If there's any reason to suspect a large draw then put a headlight bulb in circuit first. As long is doesn't light up bright then you know it's going to be safe to put the meter in.

The same technique works when investigating the cause of blown fuses - stick a bulb in place of the fuse to limit the current to a safe level and indicate when the fault remains without sacrificing more fuses.

[Chrischick]

10 hours ago, TonyHSD said:

I think for safety reasons it is a good idea to take your car to auto electrician to have a look at it especially the area behind the radio as that heat mentioned above can trigger even a car fire. 

 

 

 

[Chrischick]

Yeah! Went to surprise dealership today and once again told by big wig sales dude car is fixed. He walked me out to car and said see, as he tried to start it. It was dead like I knew it would be. I said has to be radio maybe bad wire, he put me in rental... Lol! Probably still ongoing will post when they figure it out. Received a call hours later indeed it is radio, and would get it fixed. Thanks everyone for your speedy thoughts. God Bless

[Mooly]

11 hours ago, Red_Corolla said:

Little tip; multimeter fuses are expensive. If there's any reason to suspect a large draw then put a headlight bulb in circuit first. As long is doesn't light up bright then you know it's going to be safe to put the meter in.

The same technique works when investigating the cause of blown fuses - stick a bulb in place of the fuse to limit the current to a safe level and indicate when the fault remains without sacrificing more fuses.

The DBT. A good tip actually. Its one we use all the time on mains powered stuff (using a 230v filament bulb in that case).

Car electrics are not very DVM friendly when it comes to current measurements. Even opening a door or worse operating the central locking can cause a massive current spike that a DVM will not appreciate, particularly on a low current range. There are ways and means but each case is different.

 

7 hours ago, Chrischick said:

Received a call hours later indeed it is radio, and would get it fixed.

Do let us know how it all goes. It may well be the radio but that doesn't quite compute with it being able to flatten a fully charged healthy Battery in a short time. 

[Red_Corolla]

Another good tip for quickly identifying a faulty circuit is to check for any volt drop across the fuses in mV. Blade fuses have little test points in them, so you can quickly probe your way through a fusebox this way, as long your meter and probes are up to scratch. Not so useful for very small parasitic draws, but large faults in excess of 1A will be easy to spot because you'll be dropping at least a couple of mV across the fuse element.

[Mooly]

Yup 🙂 That's an electronics engineer speaking by the sound of it.