Battery Dead

[KimFeng]

Good morning everyone, 

I have a question about my CT200H, and hoping you guys can help me out. 

My Lexus has not been driven for a month's time (maybe more). I was trying to get it started yesterday, but unfortunately, the Battery was dead and not allow me to open the door remotely. I had to open the driver's door with the key inside the fob.

I was trying to jump start it as it happened before.

This time, however, the alarm was set off, and I could not turn it off with my fob. So I disconnected it, and the little screen showed 'key not detected' with a flashing triangle warning sign when I pressed the start button.   

Today, I tried it again, the Battery was completely dead and nothing happened even I pressed the start button. 

I want to know what happened to my car, is it the Battery problem or other problems?  I hope you guys can help me out as Dealership is the least favour place I want to go.

 

Thank you so much!

[ColinBarber]

Are you able to charge the Battery? I'd disconnect it from the vehicle and fully charge it rather than trying a jumpstart. That way all the systems have enough power to turn on which means the key should be detected and you can turn off the alarm.

[08ISF]

From your description it sounds as if the problem is with the Battery in the key fob. If the house Battery were completely discharged then the alarm wouldn't sound and you wouldn't get the "key not detected" warning. Try changing the Battery in the key.

[KimFeng]

7 minutes ago, ColinBarber said:

Are you able to charge the battery? I'd disconnect it from the vehicle and fully charge it rather than trying a jumpstart. That way all the systems have enough power to turn on which means the key should be detected and you can turn off the alarm.

Hi,

 

Thank you for your reply!

I was trying to charge the Battery, but the alarm kept going off. So I had to remove the jump start cable. 

The thing is that I am not able to reach the back of the car as there is no power to open the boot. 

[ColinBarber]

When you had the jump start cables attached where you able to quickly open the boot? You can then disconnect everything and charge.

[ColinBarber]

14 minutes ago, 08ISF said:

If the house battery were completely discharged then the alarm wouldn't sound and you wouldn't get the "key not detected" warning. Try changing the battery in the key.

That occurred when the jump Battery was connected. The alarm will go off as it is detecting voltage fluctuations - this is an anti-tamper mechanism. 

[KimFeng]

38 minutes ago, 08ISF said:

From your description it sounds as if the problem is with the battery in the key fob. If the house battery were completely discharged then the alarm wouldn't sound and you wouldn't get the "key not detected" warning. Try changing the battery in the key.

Thank you for the reply.

I am trying to change the key fob Battery today, but now the car seems to have complete flat Battery. 

The alarm went off when the cables were attached to the Battery, so I assume it was charging the Battery? 

[KimFeng]

27 minutes ago, ColinBarber said:

When you had the jump start cables attached where you able to quickly open the boot? You can then disconnect everything and charge.

That sounds like a plan! Thanks for that!

 I was charging the Battery from the front, is it ok for that?

I quickly disconnected the cable once the alarm went off, ang got em brassed as in the open area.

 

[ColinBarber]

11 minutes ago, KimFeng said:

That sounds like a plan! Thanks for that!

 I was charging the battery from the front, is it ok for that?

Yes it's fine to use the front for charging/jumping but as you have found, if the Battery is really flat then you will trigger the alarm 😞

If the boot won't release when you provide power then the only other option is to use the mechanical release which means climbing into the boot by lowering the seats which is a pain:

[KimFeng]

 

16 minutes ago, ColinBarber said:

Yes it's fine to use the front for charging/jumping but as you have found, if the battery is really flat then you will trigger the alarm 😞

If the boot won't release when you provide power then the only other option is to use the mechanical release which means climbing into the boot by lowering the seats which is a pain:

Thank you for the help!

I will try that later (at work)as it seems that is the only way so far, I hope it is just the flat Battery problem rather than other electrical issues.  

'Key not detected' gave  me  quite a scare, I thought the sensor for the key fob was broken.  

I saw a thread saying that if the Battery is flat too long or too low, it will not recognise the fob, and it needs to be reprogrammed.  

 

Also, will the alarm go off if I charge from the back? 

[DrShockr]

1 hour ago, KimFeng said:

 

Thank you for the help!

I will try that later (at work)as it seems that is the only way so far, I hope it is just the flat battery problem rather than other electrical issues.  

'Key not detected' gave  me  quite a scare, I thought the sensor for the key fob was broken.  

I saw a thread saying that if the battery is flat too long or too low, it will not recognise the fob, and it needs to be reprogrammed.  

 

Also, will the alarm go off if I charge from the back? 

You have to follow the correct sequence of events to stop the alarm:

1. Change the Battery in your key before anything else.

2. As the car is dead, unlock the front door using the mechanical key

3. Open bonnet and connect jump cables

4. The alarm should probably start sounding as soon as there is a little bit of charge in the car Battery. Press the unlock button on your key fob to disable the alarm. 

 

You can then carry on trying to start the car/charge from the front/open the boot and remove the car Battery etc.

[KimFeng]

1 minute ago, DrShockr said:

You have to follow the correct sequence of events to stop the alarm:

1. Change the battery in your key before anything else.

2. As the car is dead, unlock the front door using the mechanical key

3. Open bonnet and connect jump cables

4. The alarm should probably start sounding as soon as there is a little bit of charge in the car battery. Press the unlock button on your key fob to disable the alarm. 

 

You can then carry on trying to start the car/charge from the front/open the boot and remove the car battery etc.

Thank you for the advice. 

I have tried to unlock the alarm with the key, but the fob was not doing anything even I can see the red dot flashing on the key. 

I assume the key still have active Battery? 

 

[DrShockr]

Also remember, if you do remove the Battery completely from the car, the locks will no longer work, including the boot lock, if you shut the boot, it will lock and you won't be able to open it unless you crawl into the back as per Colin's post above. If possible, leave the boot slightly ajar so it doesn't engage the locking mechanism

[DrShockr]

5 minutes ago, KimFeng said:

Thank you for the advice. 

I have tried to unlock the alarm with the key, but the fob was not doing anything even I can see the red dot flashing on the key. 

I assume the key still have active battery? 

 

Given the message on the dash, I would change the key Battery anyway. 

Not sure about others but I've found I have to change the key batteries much more regularly (~twice a year) with this car than  others I've had before (once every few years). 

[KimFeng]

9 minutes ago, DrShockr said:

Given the message on the dash, I would change the key battery anyway. 

Not sure about others but I've found I have to change the key batteries much more regularly (~twice a year) with this car than  others I've had before (once every few years). 

But today the car is completely dead, even the message did not show up any more.

I am hoping it is just the Battery is dead.  

[stormchaser]

It,s 100% your Battery.Anything below 9 volts and the system just won,t want to do anything.It won ,t be your key fob Battery unless it was dead anyway.I had similar problem last winter when my original packed up after 8 years.I bought a Yuasa identical Battery and replaced the dead one and all is back to normal now.These are known to do very strange things when the Battery is low/dying.

Good luck.

[LenT]

13 hours ago, KimFeng said:

I was trying to charge the battery, but the alarm kept going off. So I had to remove the jump start cable. 

I’m not too clear if you’re trying to charge the Battery ie using a Battery charger, or trying to jump start it from a donor Battery?

If the Battery is totally flat then trying to use a donor Battery probably won’t work - unless it’s a power pack.

You might have more success using a good trickle charger overnight eg a CTEK.  They’re useful to have anyway.  But in any case a new Battery sounds like a worthwhile investment if the present one is the original!

[Barry14UK]

Every time you allow the 12v Battery to go flat you shorten it's life, the efficiency of which falls away over time anyway, requiring more frequent charging.  It seems to me that you need a new 12v Battery and then ensure that is charged regularly by one means or another so it does not go flat.  Cars should be fitted with an easily seen state of charge indicator as if you have any doubts you need to connect a meter direct to the Battery or elsewhere where there is voltage to check level which can be a nuisance.  

[LenT]

5 hours ago, Barry14UK said:

Cars should be fitted with an easily seen state of charge indicator as if you have any doubts you need to connect a meter direct to the battery or elsewhere where there is voltage to check level which can be a nuisance.  

CTEK makes a charger connection lead which is wired directly to the Battery posts and has a traffic light LED indicator on the end that connects with the charger.  I have them fitted to our cars, which means I just lift the bonnet and can immediately tell the state of charge from which colour LED is flashing.

https://www.ctek.com/uk/battery-chargers-12v-24v/car-charger/ctx-indicator-eyelet-m8

Another version plugs into the accessory power socket inside the car.

[KimFeng]

7 hours ago, stormchaser said:

It,s 100% your battery.Anything below 9 volts and the system just won,t want to do anything.It won ,t be your key fob battery unless it was dead anyway.I had similar problem last winter when my original packed up after 8 years.I bought a Yuasa identical battery and replaced the dead one and all is back to normal now.These are known to do very strange things when the battery is low/dying.

Good luck.

Thanks for the statement, because the car was starting to act odd, key not detected even the key is in the car and in working order.

 I bought this and try to recharge the Battery. Hopefully this will work.

 https://www.amazon.co.uk/gp/product/B08ZSBRW6Q/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[KimFeng]

7 hours ago, LenT said:

I’m not too clear if you’re trying to charge the battery ie using a battery charger, or trying to jump start it from a donor battery?

If the battery is totally flat then trying to use a donor battery probably won’t work - unless it’s a power pack.

You might have more success using a good trickle charger overnight eg a CTEK.  They’re useful to have anyway.  But in any case a new battery sounds like a worthwhile investment if the present one is the original!

Apologise for not saying clearly, my intention was to get it recharged and then go to garage to get the Battery replaced. 

I do not want to pay hundred quid to get it towed to the garage, although that is my final option. 

[LenT]

4 hours ago, KimFeng said:

 I bought this and try to recharge the battery. Hopefully this will work.

 https://www.amazon.co.uk/gp/product/B08ZSBRW6Q/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

I don’t know anything about this make, although I do see that lower down the page it does state, under ‘Warning’, that it ‘Can not activate a dead Battery.’

Still, it’s worth a try - and a good trickle charger is always worth having.  Good luck with it.

 But as I say, if it’s the original 2014 Battery it’s done pretty well!

[Malc]

4 hours ago, KimFeng said:

I do not want to pay hundred quid to get it towed to the garage, although that is my final option.

are you a RAC or AA member ?  Green Flag or whatever ......  they mighty assist

Malc

[Barry14UK]

Sometimes you can get a flat Battery to charge by coupling up another reasonably good 12v Battery to it in parallel and then charging the two together. 

[KimFeng]

27 minutes ago, Barry14UK said:

Sometimes you can get a flat battery to charge by coupling up another reasonably good 12v battery to it in parallel and then charging the two together. 

Tried to jump start it this morning, and it seems won't recharge. Also shows the message 'check hybrid system, which seems a bad news. 

After 10 mins, I tried to jump start again, nothing happened, the car is still dead. 

Do I need to replace the whole hybrid system in that case or just the Battery?