Low Key Battery
01-25-12, 06:30 AM
#16
01-25-12, 05:05 PM
#18
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I got the credit card key as well (no charge) plus two electronic key fobs. I seem to recall this might be standard in Canada.
(Heck Lexus has to throw in something to justify the huge difference in MRSP and freight and the fact that the extended warranty covers only about half of the components that are covered in the US)
(Heck Lexus has to throw in something to justify the huge difference in MRSP and freight and the fact that the extended warranty covers only about half of the components that are covered in the US)
01-28-12, 08:52 AM
#21
01-28-12, 07:51 PM
#23
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I guess keyless feature requires a key alway emit something. All my cars with regular fob didn't need change battery ever. So when keyless system was introduced I changed batteries once in two years, but it looks like new models increased key detection distanc, so now battery needs change every 8-15 months (still have no idea why such difference)
01-30-12, 09:10 AM
#24
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I have also read on this board that battery life is reduced due to the key fob communicating with nearby phones. It is recommended that you isolate the fob when not in use but I am not sure how to do that. Maybe I need a lead lined box :-)
01-30-12, 09:43 AM
#25
Lead Lap
Battery life -
I guess keyless feature requires a key alway emit something. All my cars with regular fob didn't need change battery ever. So when keyless system was introduced I changed batteries once in two years, but it looks like new models increased key detection distanc, so now battery needs change every 8-15 months (still have no idea why such difference)
All in all, the usefulness these small batteries provide far outweighs the requirement to change them every 12 to 18 months.
Best Wishes to all, Mikey Lulejian - Lake Oconee, GA
01-30-12, 09:10 PM
#26
! I looked on the Carson and L-Tuned and can't find the credit card key listed. That said, what is the lowest priced place I can get a replacement and how much is it?
01-31-12, 05:12 PM
#28
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I just tried this and it works. The fob isn't recognised if it is wrapped in foil. As far as battery usage goes however, it will still be transmitting a signal and therefore using battery power. The only sure way I can think of to conserve battery power is to remove the battery if you are going on holidays or won't be using the fob for a significant period of time.
01-31-12, 06:15 PM
#29
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If I did design of fob, it could transmit signal only if can receive something from a car and recognize that it is yours. A car has much bigger battery so periodic transmission won't drain it in any way. But sure having receiver will make it more expensive.
02-01-12, 09:51 AM
#30
The CR1632 battery that is used in the wireless remote key system of the Lexus LS460s is a Lithium Magnesium Dioxide chemistry type device. Typical self-discharge rates for these types of batteries is less than 1% per year when they are stored at moderate temperatures. You can expect units that have been in proper storage for several years to perform satisfactorily.
These types have been in use for a long time and when they are used in the old type keys such as the LS400 - it used a CR1616 - they last a long time. I had my LS400 ten years and never changed the key batteries. And batteries in garage-door remotes last a long time too in moderate use.
The old type wireless keys that operated the doors and some other features but not the ignition, and garage door openers are just “burst type RF transmitters” and only use power from the battery when a button is pressed. The old wireless keys just transmitted for a fraction of a second when a button was pressed no matter how long you held the button. The garage door openers however continue to transmit as long as a button is held down and consume more from their batteries depending on how they are operated. The batteries in these types of devices might still perform satisfactorily even when they have been sitting idle for 15 years if they have been lightly used.
The new wireless keys are different sorts of gadgets. They operate much like the old devices in both the “far field” (ranges beyond 5 or 6 feet from the car) and the “near field” (ranges closer than 5 or 6 feet from the car) in that they are a burst type RF transmitter when the OPEN and LOCK buttons are pressed. However when they are in the “near field” such as closer than five or 6 feet along the sides near the doors, or near the trunk, or in the interior of the car they also act as transponders (transponders automatically transmit responses when they receive signals that are addressed to them) in response to signals that the car generates, allowing us to operate the car with the remote still in our pocket. Because they are transponders, they have to employ a radio receiver that is powered on all the time because they have no way to know the range to the car and must be ready at all times. That continuously powered receiver continuously consumes power from the battery in the remote and that causes the battery to last only about two or three years even if the remote is never used, so when the battery in one of your remotes starts reporting “Low Key Battery” then you should replace the batteries in both of them. I have a 2011 Toyota Sienna too and it has a keyless system much like the LS460. The wireless key seems to be the exact same size as the Lexus but it uses a CR2032 battery, that has about 58% more capacity so perhaps they have realized that the life of the CR1632 in these applications is marginal.
So, for those of you who have a deeper interest here is some more information to help you understand.
Those clever car designers have provided us a visual indicator to tell when the remote keys are transmitting RF signals. If you will take one of your remotes and operate the LOCK or UNLOCK button with your thumb while observing the face of the remote, just above your thumb, you will see a red light flash momentarily each time your press one of the buttons. If you can’t see the light flash then your view of the light may be obstructed by a mal-positioned cover – remove the cover or reposition it (actually I think one of my leather covers has the hole punched in the wrong place because I never can get it positioned so that I can see the light). When you see that light flash that is an indication that a coded signal has just been transmitted to your car, if it is range. Now remember, when you see that red light on the remote flash it is an indication of a transmission and it is related to some things that I will explain later. Red light flash on the remote equals transmission from the remote to the car – got it?
Let’s start with the trunk operation because it is the simplest to explain. With one of the remotes in your hand, positioned so that you can see the transmission-indicator light, observe the indicator while you press the switch that is below the lip on the trunk. You will see the light flash on the remote and the trunk will open. In simple terms, when you press the trunk switch the car transmits a coded RF interrogation signal. If your remote key recognizes the interrogation then it will respond with a coded signal (that’s the indicator flash) telling the car that it is present and the car’s electronics will operate the trunk release solenoid.
The doors work a little differently. When the car is locked it, the car, is transmitting an interrogation signal, about every five seconds, near the doors along both sides of the car – this field ranges out about 5 or 6 feet (I think this signal stops after a couple of weeks, if there is no activity, to conserve the car battery). When the remote key is within range and receives a coded signal that is addressed to it, it will respond with a coded signal to let the car know that it is present and then lifting the door handle will open the door. You can see an indication of this exchange by locking the doors and then walking up to your car with one of the remote keys in your hand, positioned so that you can see the transmission-indicator light. As you get near the car you will see the red light on the remote key start to flash about once every five seconds when the remote key transmits a coded signal to the car to let it know that the key is present. If the exchange continues for more than 10 minutes without the door being opened then the interrogation ceases and the touch-open feature is disabled. The touch-open feature will remain disabled until the doors are unlocked by operation of the OPEN button on the remote key. A couple of examples of when this might come into play would be if you tried storing your keys on a wall-hook beside your car or if you walked up to your car and stood near the door engaged in a conversation that lasted longer than 10 minutes.
And the ignition is different too. When the ignition is off the car is running a continuous interrogation inside to detect a valid key. You can see an indication that this is going on by holding a remote key in your hand while the ignition is off. You will see the red indicator on the remote key flash about once every 5 seconds. When you see that flash it is a indication that the remote key has received a coded signal from the car that it recognizes and is transmitting a coded signal to the car to let it know that a valid key is present. Proper operation of the IGNITION button will start the car when a valid key is present. After the car starts the interrogation ceases. The key does not need to present in the car after it is running and the ignition can be turned off without the key present. If a door is opened, then the interrogation process starts again and will report “Key is not detected” if the key is not detected. An example of this would be if you are taking your wife to the bus stop and when you started the car her key was in her purse and you thought yours was in your pocket, but instead, your key is at home. When your wife gets out of the car and the door closes you will get that “Key is not detected” message and a helpless feeling as she walks away.
The continuous power draw from the receiver and the numerous transponder responses certainly makes the battery life for these devices much shorter than the older types. But, I still love the “magic”. Routinely change your remote batteries after about two years of service as they are very inexpensive and for many it is a DIY project and you can go to any Toyota Dealer and get them changed for a reasonable price if the DIY is not possible.
These types have been in use for a long time and when they are used in the old type keys such as the LS400 - it used a CR1616 - they last a long time. I had my LS400 ten years and never changed the key batteries. And batteries in garage-door remotes last a long time too in moderate use.
The old type wireless keys that operated the doors and some other features but not the ignition, and garage door openers are just “burst type RF transmitters” and only use power from the battery when a button is pressed. The old wireless keys just transmitted for a fraction of a second when a button was pressed no matter how long you held the button. The garage door openers however continue to transmit as long as a button is held down and consume more from their batteries depending on how they are operated. The batteries in these types of devices might still perform satisfactorily even when they have been sitting idle for 15 years if they have been lightly used.
The new wireless keys are different sorts of gadgets. They operate much like the old devices in both the “far field” (ranges beyond 5 or 6 feet from the car) and the “near field” (ranges closer than 5 or 6 feet from the car) in that they are a burst type RF transmitter when the OPEN and LOCK buttons are pressed. However when they are in the “near field” such as closer than five or 6 feet along the sides near the doors, or near the trunk, or in the interior of the car they also act as transponders (transponders automatically transmit responses when they receive signals that are addressed to them) in response to signals that the car generates, allowing us to operate the car with the remote still in our pocket. Because they are transponders, they have to employ a radio receiver that is powered on all the time because they have no way to know the range to the car and must be ready at all times. That continuously powered receiver continuously consumes power from the battery in the remote and that causes the battery to last only about two or three years even if the remote is never used, so when the battery in one of your remotes starts reporting “Low Key Battery” then you should replace the batteries in both of them. I have a 2011 Toyota Sienna too and it has a keyless system much like the LS460. The wireless key seems to be the exact same size as the Lexus but it uses a CR2032 battery, that has about 58% more capacity so perhaps they have realized that the life of the CR1632 in these applications is marginal.
So, for those of you who have a deeper interest here is some more information to help you understand.
Those clever car designers have provided us a visual indicator to tell when the remote keys are transmitting RF signals. If you will take one of your remotes and operate the LOCK or UNLOCK button with your thumb while observing the face of the remote, just above your thumb, you will see a red light flash momentarily each time your press one of the buttons. If you can’t see the light flash then your view of the light may be obstructed by a mal-positioned cover – remove the cover or reposition it (actually I think one of my leather covers has the hole punched in the wrong place because I never can get it positioned so that I can see the light). When you see that light flash that is an indication that a coded signal has just been transmitted to your car, if it is range. Now remember, when you see that red light on the remote flash it is an indication of a transmission and it is related to some things that I will explain later. Red light flash on the remote equals transmission from the remote to the car – got it?
Let’s start with the trunk operation because it is the simplest to explain. With one of the remotes in your hand, positioned so that you can see the transmission-indicator light, observe the indicator while you press the switch that is below the lip on the trunk. You will see the light flash on the remote and the trunk will open. In simple terms, when you press the trunk switch the car transmits a coded RF interrogation signal. If your remote key recognizes the interrogation then it will respond with a coded signal (that’s the indicator flash) telling the car that it is present and the car’s electronics will operate the trunk release solenoid.
The doors work a little differently. When the car is locked it, the car, is transmitting an interrogation signal, about every five seconds, near the doors along both sides of the car – this field ranges out about 5 or 6 feet (I think this signal stops after a couple of weeks, if there is no activity, to conserve the car battery). When the remote key is within range and receives a coded signal that is addressed to it, it will respond with a coded signal to let the car know that it is present and then lifting the door handle will open the door. You can see an indication of this exchange by locking the doors and then walking up to your car with one of the remote keys in your hand, positioned so that you can see the transmission-indicator light. As you get near the car you will see the red light on the remote key start to flash about once every five seconds when the remote key transmits a coded signal to the car to let it know that the key is present. If the exchange continues for more than 10 minutes without the door being opened then the interrogation ceases and the touch-open feature is disabled. The touch-open feature will remain disabled until the doors are unlocked by operation of the OPEN button on the remote key. A couple of examples of when this might come into play would be if you tried storing your keys on a wall-hook beside your car or if you walked up to your car and stood near the door engaged in a conversation that lasted longer than 10 minutes.
And the ignition is different too. When the ignition is off the car is running a continuous interrogation inside to detect a valid key. You can see an indication that this is going on by holding a remote key in your hand while the ignition is off. You will see the red indicator on the remote key flash about once every 5 seconds. When you see that flash it is a indication that the remote key has received a coded signal from the car that it recognizes and is transmitting a coded signal to the car to let it know that a valid key is present. Proper operation of the IGNITION button will start the car when a valid key is present. After the car starts the interrogation ceases. The key does not need to present in the car after it is running and the ignition can be turned off without the key present. If a door is opened, then the interrogation process starts again and will report “Key is not detected” if the key is not detected. An example of this would be if you are taking your wife to the bus stop and when you started the car her key was in her purse and you thought yours was in your pocket, but instead, your key is at home. When your wife gets out of the car and the door closes you will get that “Key is not detected” message and a helpless feeling as she walks away.
The continuous power draw from the receiver and the numerous transponder responses certainly makes the battery life for these devices much shorter than the older types. But, I still love the “magic”. Routinely change your remote batteries after about two years of service as they are very inexpensive and for many it is a DIY project and you can go to any Toyota Dealer and get them changed for a reasonable price if the DIY is not possible.
Last edited by jmcraney; 02-01-12 at 09:55 AM. Reason: typo