Sign in to follow this  
maximus999

Battery Keeps Draining

Recommended Posts

Hi all, My partner has a yaris 53 reg 1.0L. Some time ago the Battery was keep going flat, i changed the Battery and it is still doing the same. I have tested the Battery when fully charged and had it on a mechanics Battery tester and it all checks out ok. I am getting charge from the alternator at 14.05 Volts when idle, which seems fine. I have tested for a drainage and there is non.

Does anyone know or have experienced why it could be doing this.

Many thanks for any replies.


Ian.

Share this post


Link to post
Share on other sites

Could there be something simple like a boot light being left on?

Share this post


Link to post
Share on other sites

Hi all, My partner has a yaris 53 reg 1.0L. Some time ago the battery was keep going flat, i changed the battery and it is still doing the same. I have tested the battery when fully charged and had it on a mechanics battery tester and it all checks out ok. I am getting charge from the alternator at 14.05 Volts when idle, which seems fine. I have tested for a drainage and there is non.

Does anyone know or have experienced why it could be doing this.

Many thanks for any replies.

Ian.

What is the alternator voltage at fast idle with the headlights, heated rear window, heater blower and wipers switched on? How have you tested for Battery drain. If you say there is none then the Battery cannot drain. Something of a contradiction in terms!

Regards Geoff Peace.

Share this post


Link to post
Share on other sites

Could there be something simple like a boot light being left on?

He's got a boot light!!???!!

Share this post


Link to post
Share on other sites

If there genuinely is no current drain - tested I hope with doors locked? - then it's the alternator. Check as per Geoff above...

I assume it's central locking with manual key unlocking.

Usual fault if not alternator is a vanity light - interior of some type.

Share this post


Link to post
Share on other sites

Hi all, My partner has a yaris 53 reg 1.0L. Some time ago the battery was keep going flat, i changed the battery and it is still doing the same. I have tested the battery when fully charged and had it on a mechanics battery tester and it all checks out ok. I am getting charge from the alternator at 14.05 Volts when idle, which seems fine. I have tested for a drainage and there is non.

Does anyone know or have experienced why it could be doing this.

Many thanks for any replies.

Ian.

What is the alternator voltage at fast idle with the headlights, heated rear window, heater blower and wipers switched on? How have you tested for Battery drain. If you say there is none then the Battery cannot drain. Something of a contradiction in terms!

Regards Geoff Peace.

Hi, the voltage is between 13.2 and 13.9 volts with loads. Battery drain was tested on a machine at a dealership and showed there is no drain.

Share this post


Link to post
Share on other sites

If there genuinely is no current drain - tested I hope with doors locked? - then it's the alternator. Check as per Geoff above...

I assume it's central locking with manual key unlocking.

Usual fault if not alternator is a vanity light - interior of some type.

Hi, Vanity light was the first thing I disconnected thinking it was that, but no. It is manual locking, this has got me really puzzled

Share this post


Link to post
Share on other sites

If there genuinely is no current drain - tested I hope with doors locked? - then it's the alternator. Check as per Geoff above...

I assume it's central locking with manual key unlocking.

Usual fault if not alternator is a vanity light - interior of some type.

Hi, Vanity light was the first thing I disconnected thinking it was that, but no. It is manual locking, this has got me really puzzled

Have you connected an ammeter in series with the Battery earth connection? That is the only sure way to test for current drain.

Regards Geoff Peace.

Share this post


Link to post
Share on other sites

If there genuinely is no current drain - tested I hope with doors locked? - then it's the alternator. Check as per Geoff above...

I assume it's central locking with manual key unlocking.

Usual fault if not alternator is a vanity light - interior of some type.

Hi, Vanity light was the first thing I disconnected thinking it was that, but no. It is manual locking, this has got me really puzzled

Have you connected an ammeter in series with the Battery earth connection? That is the only sure way to test for current drain.

Regards Geoff Peace.

Hi, Battery earth, I tested it with the positive lead for drainage and set the meter to 10A

Share this post


Link to post
Share on other sites

A 0.50amp drain will flatten a 40AH Battery in under 3 days..

But more to the point:

When does it go flat?

After being left unused? And for how long?

Or even when being used?

If the latter - being used- are the journeys short 1-2 miles or longer say 10 miles.? Day or night usage?

Share this post


Link to post
Share on other sites

Hi. It seems to be after it has stood for a day or so and the power steering feels heavy when driven prior to it dying she says. The Battery is showing 12.7 volts when tested with engine off

Share this post


Link to post
Share on other sites

If there genuinely is no current drain - tested I hope with doors locked? - then it's the alternator. Check as per Geoff above...

I assume it's central locking with manual key unlocking.

Usual fault if not alternator is a vanity light - interior of some type.

Hi, Vanity light was the first thing I disconnected thinking it was that, but no. It is manual locking, this has got me really puzzled

Have you connected an ammeter in series with the Battery earth connection? That is the only sure way to test for current drain.

Regards Geoff Peace.

Hi, Battery earth, I tested it with the positive lead for drainage and set the meter to 10A

The usual method is to connect the ammeter on the earth side. It is good practice to set the ammeter to its highest scale initially in case the current draw is excessive. However, once you have established it is no going to blow the meter fuses, you will not be able to read the draw on the 10A scale and need to switch to the highest milliamp scale then to the next lower scale and so on to obtain a meaningful readout. The current draw should be less than 20 milliamps. i.e. 0.02A When you are taking the reading do not switch anything on as it will blow the meter fuse. A Battery reading 12.7V is fully charged, you now need an accurate reading of the residual current draw.

Regards Geoff Peace.

Share this post


Link to post
Share on other sites

Hi. It seems to be after it has stood for a day or so and the power steering feels heavy when driven prior to it dying she says. The battery is showing 12.7 volts when tested with engine off

If the power steering is heavy that strongly suggests the Battery is not getting charged properly as the alternator should be providing all power with the engine running.

Have you checked the drive belt?

Regarding meter testing there is a catch. If something is not turning off properly, breaking the power by putting the meter in line may well reset it. It might then remain properly off until next driven. You need to try to get the meter in place to carry the power before breaking the power circuit.

Share this post


Link to post
Share on other sites

One day to drain a Battery seems a huge current draw.. about 1 amp would half discharge the typical 50AH Battery in 24 hours.

Share this post


Link to post
Share on other sites

Hi. It seems to be after it has stood for a day or so and the power steering feels heavy when driven prior to it dying she says. The battery is showing 12.7 volts when tested with engine off

If the power steering is heavy that strongly suggests the Battery is not getting charged properly as the alternator should be providing all power with the engine running.

Have you checked the drive belt?

Regarding meter testing there is a catch. If something is not turning off properly, breaking the power by putting the meter in line may well reset it. It might then remain properly off until next driven. You need to try to get the meter in place to carry the power before breaking the power circuit.

Ah! now that is very true. The only way then is to install a Battery keeper before disconnecting. There are an increasing number of cars usually toward the upper end of the market which can have as much as 300mA drain when the engine is switched off. The system powers down after about half an hour only then will you obtain an accurate reading for current drain. This technology has not reached the Yaris yet, but give it time!

Regards Geoff Peace.

Share this post


Link to post
Share on other sites

You could rule out some devices by removing thier fuses. IE heated rear screen, radio etc. I had a headlight adjuster motor that was constantly hunting up and down trying to level the headlights. Whilst that was happening the wiper motor would not turn off untill the headlights were off even with the keys out of the ignition. You could remove fuses and put the ammeter across thier contacts and see of each fuse was drawing current. Any thing over 0.1A could be the culprit. The only things that should be drawing any current whilst the car is parked are the radio, alarm, Central locking/brain of the car.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this