Flat 12V battery

[cadmasteruk]

I inadvertently left the lights on on my Auris Hybrid T-Spirit (2011 - keyless entry) and the 12V Battery is so drained that I cannot get into the car, even with the metal key. Is there any way to open the bonnet so that I can connect a booster pack to the jump start terminals?

[Gerg]

Your not being able to open the door is not because the 12v Battery is really flat, it is almost certainly because the lock is very stiff through lack of use.

You need to get some thin oil/WD40 etc. or equivalent into the lock, which is easier said than done, as the stiff bit may be some way into the mechanism.

Also, turning the key repeatedly might loosen it up.  Others have used a pair of pliers on the key.  But care is needed doing that! else you'll snap the key off!!!!

Once under the bonnet, there is a terminal that is inside the fuse box on the far passenger side of the engine bay.  The terminal, amongst all the other fuse box stuff, has a red plastic flip-up cover, which when pivoted up reveals a metal blade that you can attach your positive (red) jump lead to.  You can attach the negative jump lead to one of the bare suspension nuts nearby, or any shiny, substantial part of the engine.  There is a 'map' of the fuse box on the underside of the fuse box lid.

Best practice is to put the positive (red) one on first, then the black (negative) one on last.  And when done, remove the negative one first.  This isn't essential.

The car doesn't need much power at all from the booster Battery to start up.

 

 

[cadmasteruk]

Gerg,

thanks for the quick response, the metal key is turning, but nothing happens - I would expect to hear the relays operate on the other doors.

If I cannot gain access to either the bonnet or the boot, I do not know what I can do.

[Gerg]

You probably already know, the door unlocks by turning the key anti-clockwise.

If the Battery is flat, then the door relays won't operate, you'll only be able to open the drivers door.

Patience and persistence usually wins with the door lock.

[Gerg]

If the door can't be unlocked using the key and judicious extra leverage, then you are into the realms of the AA etc., you are then trying to break in to your car, there is no easy short cut.

[cadmasteruk]

You were right about persistence - got the driver's door open, so now have access to the engine bay. I will try applying a booster pack to the jump terminals (once it has charged) and see if I can get it going.

[PeteB]

1 hour ago, Gerg said:

...If the battery is flat, then the door relays won't operate, you'll only be able to open the drivers door...

On top of that, if you had deadlocked (double locked) the car, then none of the doors other than the driver's can be opened until power is restored.

[Gerg]

If you have a genuine Toyota (Yuasa brand) Battery, then they don't charge up quickly. 

An overnight charge with one of the newer 'Smart Battery chargers' if you can do that, is a good idea. 

The 12 volt Battery is charged by the car at the same rate (quite slowly, actually) whether the car is in traffic, on the motorway, or sat stationary (on your drive?) with the system fully on. 

The Toyota dealer price for a new battery was/is £125. It is an unusual spec. And the same battery on eBay is more!

[cadmasteruk]

Tried the booster pack, orange engine symbol at bottom left of the display comes on, goes off when I press the brake pedal, but no response from the power button.

Now it's raining - don't want the bonnet open with electrics exposed - this is not a good day!

[Gerg]

I've only limited experience with modern booster packs.  My one automatically turns off the 12v boost after a set time, and that's not very long! (90 seconds?)

Is yours perhaps dumping some charge into the Battery, but by the time you're sat in the car the booster has turned itself off?  You are then trying to start up the car on the small amount of charge which has successfully got into the Battery before the booster pack shut down, but this isn't enough?? 

Just a guess.  If this is the case, you might need a second person to activate/check the booster, whilst you are in the driver's seat pressing the start button/brake pedal etc.

I doubt very, very much that you have harmed the car at all, but you might have brought ahead the battery's death, but not necessarily.  When you do finally get the car 'up', then it is quite possible that you get some dash error lights on.  These should sort themselves out after a minute or so.

In case you didn't know, the 12v Battery powers up the computers, and operates the contactor(s) and the brake pump.  The engine is started from the computer's instruction to drive one of the transmission's electric motors from the high voltage (traction) battery.  So, in normal use, the battery doesn't supply any heavy current like in a regular car.

[TonyHSD]

Hi, all good advice here. Just booster start the car and leave it in ON mode for few hours, if you can , secured driveway or similar and keep an eye on. The car will recharge your small Battery and you may not need to buy a new one. If you already done that and still weak Battery you will need to buy a new one and if you not driving the car regularly you will need to keep the car ON let say once a week for an hour will help you have your Battery operate as it should. Make sure you have no any additional devices installed like insurance black box or gps tracking device, these are forbidden for Toyota hybrids, they will kill brand new car battery in just one week time. 👍
Regards 

[Catlover]

1 hour ago, cadmasteruk said:

Tried the booster pack, orange engine symbol at bottom left of the display comes on, goes off when I press the brake pedal, but no response from the power button.

Now it's raining - don't want the bonnet open with electrics exposed - this is not a good day!

Make your day better!  You 12v Battery is in the boot, right hand side under the boot floor carpet. Put you charger across the Battery. It shouldn’t take much time to put enough in to start up the computer bits, once that happens it will use the hybrid Battery to charge up the 12v., but do that with more then the accessories button pressed, you want all lights displayed on the dash so your petrol engine kicks in to charge up the hybrid battery when ever it dictates.

[Biomecanoid]

Just get a charger for a wall outlet to charge the Battery in you home. I have done it before when in need.

[cadmasteruk]

Success (I think!) Dropped the rear seat back and manually opened the tailgate so I could get to the Battery and put the booster pack directly on the terminals. Set off the alarm, which would not respond to the key buttons, but eventually stopped. Gave it a few minutes to absorb some charge from the booster and away it went. Driven it for half an hour so I'm hoping that will be enough till I need to fetch my wife from work, which will give it another forty-odd minutes of running time.

[flash22]

The hybrids use an AGM type Battery they charge low and slow it could take up to a week to recharge fully, so be prepared - you may get an engine light this is caused by low voltage (the modules lose communication and freak out)

[Catlover]

If you do need a relacement 12v Battery get one from Mr Toyota. I searched the internet for one, didnt think of asking Toyota. I bought one, drove 35 each way to collect, couldnt get it fitted there and then (ITS AN HYBRID), and then found out the Toyota original equioment was £10 cheaper anyway. No problem fitting myself.  Lesson learnt.

[TAO]

Re Auris Battery boosting: I’m using a Ring Smart Maintenance Battery Charger fitted to the smaller boot based starter Battery & plugged into an extension lead to the house mains.  Don’t like trapping the lead in the hatch door but if I do that in order to lock the car for overnight charging car security, will it trigger the alarm?  Has anyone tried this? Not worried re garage as the door won’t squeeze the extension lead.  Any ideas how long it takes for a previously Auris hybrid flat battery (boosted to start & drive yesterday) takes to reach full charge using this method?

 

[TonyHSD]

You can take the lead through window and shut the doors as usual and lock them with the service key build into your key fob. No need alarm just to keep the car secure. 

[TAO]

Given that the alarm is automatically on & activated, wouldn’t an open window with lead & potentially wind or rain through it trigger the alarm?  I’ve never attempted to turn off the alarm - is that in the handbook?

[TonyHSD]

13 minutes ago, TAO said:

Given that the alarm is automatically on & activated, wouldn’t an open window with lead & potentially wind or rain through it trigger the alarm?  I’ve never attempted to turn off the alarm - is that in the handbook?

If you lock the car with the key instead you ain’t activating the alarm so no worries here, just close the window up to the cable. 

[1.8 hybrid]

do you have a button to turn off the interior sensor

i think its very common to have this button

[TAO]

Given that the alarm is automatically on & activated, wouldn’t an open window with lead & potentially wind or rain through it trigger the alarm?  I’ve never attempted to turn off the alarm - is that in the handbook?

[TAO]

Thanks for your helpful replies👍

[Roy124]

My Battery in the Corolla engine bay is a Lead Acid.  Just check.

With the hybrid I am told driving the car for 30 minutes makes no difference from just sitting with it powered up.  As said above, the 12v Battery is charged by the high voltage Battery. To reach this state you need the instrument panel to display the READY light.

Now question and supposition:

With a conventional car you can use jump leads and the supplying car revving to provide power to the dead car and allow the starter motor to turn.  With the hybrid that will not work.  Now I presume the jump leads can still be used but only provide a charging current similar to a charger but is that true for an AGM battery that does not permit a high charge current?  Or can it be used with the live car not running its engine?

~~~~~

Now I have just fitted a CTEK Battery monitor.  This displays one of three LED:

Red is low charge, use a charger or drive the car,

Green is charged and charger may be disconnected,

Yellow is being charged or battery has sufficient charge. 

After a trickle charge I get the green light but this soon reverts to yellow.  

 

[Mooly]

With the engine not running you would find that in practice the voltage level of the two batteries equalised fairly quickly. Little energy would be transferred to the flat one.

There are cautions to observe. If the flat Battery has a very low terminal voltage then although little energy overall would flow, the initial current flow could be high for a few moments.

There are ways around that, it all depends on how keen you are to implement them. A series resistance in one of the jump leads (such as an old car headlight bulb) would be an ideal way of reducing current surge and limiting overall current into the Battery... it works so well because the filament has a non linear resistance vs temperature characteristic.  When cold the resistance is low and so allows decent current flow. As it warms the resistance rises and flow decrease. Even if the flat Battery were a dead short then the current limits out at the rating of the bulb. So safe for both of the cars and their batteries and charging systems.

Without knowing the exact voltages your monitor changes states at it all becomes guesswork. What you really need to know is what the red LED illuminates at and how that is interpreted against the battery manufacturers SOC (state of charge) vs the battery terminal voltage. You will see slightly different figures quoted for this.  I would suggest around 11.8V as being a lower limit where the battery is only around 25 to 35% charged. A resting voltage of 12.5V and above shows a healthy SOC but that may be interpreted as showing 'Yellow' on your tester.