Corolla battery charging problems.

[Northampton Mike]

In common with so many others my Corolla Battery goes flat if not used. I have once managed to trickle charge this Battery but some days later needed to charge it again. This time the charger would now show as charging? I then checked the charger by connecting to another car and the charger worked perfectly, indicating the problem is with the Corolla. Could it be a fuse problem and if so which fuse controls the charging from an external source?

[Parts-King]

If the car is going flat after only a few days then something is wrong. It is under warranty, why don't you book it in for investigation? 

[Northampton Mike]

Thanks for your observation and advice. I can’t claim that I had fully charged the Battery on the trickle charge as weather had me discontinue as I am not garaged. However the charge was sufficient to start the car. The problem revolves around it not now being possible to charge the Battery. Regards booking the car in it would not be possible to get to anywhere as the car is immobile/dead!

[Red_Corolla]

By the sound of it I would say your charger is not man enough for the job when the Battery is totally flat. My charger charges at 4A and it still took 7 hours to top off my Battery the other day, and it wasn't flat to start with. If the Battery has been completely dead flat then a small trickle charger wouldnt be enough to recover it. Also, the battery itself probably won't be as strong as it was any more. Going flat is a bit like going through a heart attack for a car battery - they can survive and live on, but not at 100%.

Toyota really need to look at this and come up with a solution. Either the charging provided by the car needs to be revised or the standby power consumption needs to be reduced, or both. Bottom line is it shouldn't be this easy to flatten the battery on a new (or nearly new) car.

[Roy124]

1 hour ago, Northampton Mike said:

Regards booking the car in it would not be possible to get to anywhere as the car is immobile/dead!

If you have Toyota Assistance then they should get it started or the Dealer should collect 

 

[Northampton Mike]

Thanks Roy. I would if I had assistance. However not having a good relationship with the local Toyota people at all so I am trying to sort this without involving them.

[Gerg]

22 hours ago, Northampton Mike said:

This time the charger would now show as charging? I then checked the charger by connecting to another car and the charger worked perfectly, indicating the problem is with the Corolla.

If I am understanding this correctly, then your 12v Battery charger problem is likely because your 12v Battery has drained to such a low voltage, that the 'smart' charger that you are using no longer detects the Battery as being connected at all.  The voltage at which that happens varies between brands of charger, but this seems to happen as high as ~ 8v on some makes.  I think on a CTEK it is a lower voltage, but the effect can still happen just the same.

If it is this, that problem can be bypassed by using a older-style battery charger (non-smart!) - the sort that typically used to have a ammeter guage with a needle.  Using that type, at least initially, will get around this.  Once your battery has charged to a more 'normal' flat battery voltage, say 10v - 11v, then a smart charger will work in its place, if desired.  But the battery being discharged to this extent for any length of time will affect its capacity afterwards, as mentioned above.

Also, a jump start from another car, or battery, will get the car back into the operating voltage, especially if the car can be left in the 'on' state - moving the car isn't necessary, just having the 'system' ready to drive off will charge the battery as quickly as actually driving, on this car, engine running or not.  You can then use a smart charger, as long as the battery hasn't had time to  go really flat again!

It does sound like you have a separate problem on top of the much-reported Toyota-hybrid-flat-battery syndrome.  Have you had any changes done to the car?  Particularly dash cams, but also, a bit left-field here, is the car a taxi (i.e. a taxi meter is in use)? 

The 12v battery parasitic drain can be easily measured, but it requires the car to be left completely untouched for a while (say, 40 mins), and more particularly, for practical reasons, an unusual clamp-on ammeter - which most people don't have.  At least with that meter you are better placed to measure the speed at which the battery is being discharged, and then perhaps to try to locate the culprit.

The cheapest one is this, I think, but some electrical understanding would be needed too!

https://www.amazon.co.uk/UT210E-Current-Meters-Capacitance-Tester/dp/B00O1Q2HOQ

HTH

 

[Red_Corolla]

I have the very same hall effect clamp meter, but I wouldn't trust it to be accurate enough for measuring parasitic drain unless I was just confirming a fault. You're looking for less than 50mA and I wouldn't trust those cheap clamps at such a low level. You can get clamps with mA levels of accuracy but they tend to be very expensive and only fit over small wires - normally used in industrial applications for measuring 4-20mA control signals etc.

If you don't set up the meter outside of the car (which you can't with a clamp meter) then you need to trick it into thinking everything is closed before locking it and leaving it to go to sleep. Bonnet and boot switches are often inside the lock these days, so it's a case of using a screwdriver to latch them. With a Battery inside the car like the 2.0 has, you would also want to press the button that disables the ultrasonic alarm sensors before locking it (button on the ceiling), otherwise it might well go off with the boot open.

The theory about the charger is exactly what I was thinking, but with a far more concise explanation 😊