tomtom turns on by itself?

[photoman2]

Just for the sake of posting.. last night my unit powered on by itself at 6:05pm.. I wrote this down turned it off charged it as it only had half charge. " it may have been on for a hour or so before I noticed it had powered up.. I then charged up the unit and will let it sit and see if it powers up again.. And yes it was about 7 days from when we used it last... we'll start keeping better track of it now.. The unit was our XL325 SE! Still have not turned on our XL 340 s yet from when we got it new. I just make sure to charge it once a week.. There for the XL340 s unit has not powered on by itself yet.. George

 

[ericthered]

They DO turn on by themselves

I have 2 ONE XL's and 1 930. All 3 of these have turned on by themselves. I have turned them off and come back a day or so later and have seen them turned on... it DOES happen. I can't find any pattern to it. I've had these for a couple years.

 

[Rick F.]

Dav,

I won't argue with you as you obviously already know everything.

All I meant to say is that doing a pin reset removes all power from the device so there is no current draw... the internal clock stops running... no draw on the battery other than what would be the same as shelf life. My TT has been off for 3 mos more than one time (after reset) and when I turn it on, it always showed fully charged.

BTW, I also know a bit about software AND hardware as I was a systems specialist for the FAA for 30 years and was responsible for the Air Traffic Control computer at a major airport (now retired).

Use what ever works... you don't have a reset, turn the unit on each week to reset what seems to be a 7 day cycle. Or... if you have one, use the pin reset to remove the power so it can't turn on unless you want it to be turned on.

The best choice would be that TomTom would admit to this problem in vers. 8 firmware and correct it.

 

[ericthered]

Which will come first?

A fix for TT's turning on spontaneously OR a fix for Toyotas that speed up randomly???

 

[safoocat]

tt turns itself on

We've had our TT for quite awhile and this is the first time we've caught it running without being turned on.
It could have happened before as once in awhile the battery will be dead. Ours is in our motorhome left
suctioned on the window.

It was real spooky as we went to town yesterday without locking up and when we noticed the TT
was on thought we'd had an intruder but after reading this discussion I'm relieved that wasn't the case.
Nothing else was amiss.

For the record it was one week since we used the device. We'll keep track from now on.
If this persists without a fix it's history since the Garmin Nuvi in our Prius is similar and doesn't have
this bug.
Michelle Ress

 

[canderson]

Dav,

I won't argue with you as you obviously already know everything.

All I meant to say is that doing a pin reset removes all power from the device so there is no current draw...

May or may not be true - would require confirmation with an inline current test on the battery. More likely, it's a hard reset line to either the primary processor or an ancillary chip designed to manage power-on reset to the entire system. FAA computers are a long ways from embedded systems design.

 

[Dav]

Careful Rick, reality may not be what you think it is...

May or may not be true - would require confirmation with an inline current test on the battery. More likely, it's a hard reset line to either the primary processor or an ancillary chip designed to manage power-on reset to the entire system. FAA computers are a long ways from embedded systems design.

@Rick F. And like I said, when you power up (cold boot) an embedded device like a TOMTOM, it pulls the battery charge level information from FLASH memory. In other words it shows you the last battery charge level data which it 'remembers' from before it was powered down, so you can not count on that info being accurate until after all high priority tasks are completed, which, on a GPS unit can take >3 minutes with good radio signals, possibly forever without (showing the correct battery charge display is less important than telling the customer where she is).

In other words, the battery charge level information you are seeing (and basing your statements on) may be an old reading, not a current (no pun intended) reading.

You are guaranteed to have some battery level depletion after a three month 'complete power down'! This is because of the capacitance loss due to the fact that the battery is not completely removed from the circuit. I can not explain this well, but your car battery circuitry works in a similar fashion. If you disconnect both battery terminals, your car battery can hold a charge for many months or possibly even years, versus when you turn off the ignition switch (assuming no loads, like a clock or RAM in the radio), there is no measurable current draw, yet the capacitive load (of the 'disconnected' devices) and the associated capacitive leakage, slowly eat away at the power in your battery, giving you weeks or a couple of months before the car will not start. The difference between these two is the effective size (and leakage) of the two capacitors, the first being the car's ignition system, and the second being the car/earth/etc.

I really want to help you understand all this, even though that is not what you think is going on...

@canderson - Thanks for the backup canderson. Sometimes it helps get a point across when you get another view of the same issue.

 

[canderson]

@Rick F. And like I said, when you power up (cold boot) an embedded device like a TOMTOM, it pulls the battery charge level information from FLASH memory. In other words it shows you the last battery charge level data which it 'remembers' from before it was powered down, so you can not count on that info being accurate until after all high priority tasks are completed, which, on a GPS unit can take >3 minutes with good radio signals, possibly forever without (showing the correct battery charge display is less important than telling the customer where she is).

Wish I could back you up on that, but based upon a lot of experience with systems like this, I'm doubtful.

Actually, I'd be surprised if what you describe was the case. Given the potential for a whopping inaccuracy in a stored result if the unit was left unused for a period of time, the usefulness of storing the current battery state to flash on power down wouldn't seem to be a good idea. It doesn't take that long to pull a quick A to D reading off the battery during power up. Milliseconds, actually. Moreover, the unit has to determine whether there is external power being applied and a battery present pretty much at the start so as to make the call on power source switching and battery charging - something everyone will see happening immediately at power up (rolling bars on the "battery" indicator).

One thing that can impact the initial reading vs. reading after 30 seconds or so is the way LiPo cells behave after some current is drawn from an idle cell. It's not uncommon to see a voltage rise / bounce as the cell is suddenly exercised after a period of disuse. I've seen this with NiMH chemistry, too. May have to do with the small temperature rise as current is drawn. Never investigated that phenomenon carefully to find a cause.

 

[okvol]

Been there, living with that

I got a BS in Computer Science in 81, been working since.

I've run the circuit with TomTom support, and I'm disgusted. I've dealt with many ugly IT problems before, but these folks are astoundingly obstinate in refusing to recognize their issue.

Here is my timeline:

1st try - soft reset
2nd try - reloaded OS
3rd try - reformat the system and reloaded (yes, you can format it like a flash drive with your PC - just save your maps first. And plan for a few hours of format/load time.)
4th try - RMA (cost me $10 shipping) - was sent different refurb unit (the serial number was different)

One week after replacement - it came on by itself.

I'm just going to start powercycling every six days or so.

 

[Rick F.]

I got a BS in Computer Science in 81, been working since.

I've run the circuit with TomTom support, and I'm disgusted. I've dealt with many ugly IT problems before, but these folks are astoundingly obstinate in refusing to recognize their issue.

Here is my timeline:

1st try - soft reset
2nd try - reloaded OS
3rd try - reformat the system and reloaded (yes, you can format it like a flash drive with your PC - just save your maps first. And plan for a few hours of format/load time.)
4th try - RMA (cost me $10 shipping) - was sent different refurb unit (the serial number was different)

One week after replacement - it came on by itself.

I'm just going to start powercycling every six days or so.

Hope that works for you. I don't know why TomTom won't admit to this problem... maybe their managers were trained @ Toyota.

I've said this before but I think the programmers at TomTom were 'C' students in college.

 

[safoocat]

options: turns itself on

Tomorrow it will be a week so I'll be anxious to see if my TomTom turns itself on again or if this was a one time occurrence. How about leaving it on? Do they draw enough current for that to be an issue? I might consider it since I have a small solar panel on my rv engine battery that keeps it topped up and a voltage
monitor so I could keep tabs on if the TT is wearing the battery down.

However I'm going to wait until after tomorrow to see if it was a one time fluke or not.
The six day power up isn't a bad idea as it would give one a chance to make sure all their gear is in working order while at it.

What can we expect from a unit named TomTom?

Michelle Ress, N6DGZ

 

[mikealder]

Michelle, the easy way to prevent the device from switching on of its own choice is to switch it off then press the reset button on the base of the device, this shuts it down fully until the next time the on/ off switch is pressed. You don't mention which TT you own but a great deal of the models have a reset switch on the base so give it a prod with a paperclip and leave it for weeks without an issue (otherwise you can almost set you watch by the auto switch on 168 hours give or take a couple of minutes).
If your device is one of the newer units that uses the on/ switch as a reset button then there is very little that can be done. Note resetting a device doesn't wipe out any data or settings, it simply shuts the device off fully rather than the suspend state you get with the on/ off switch.

From what I have seen this problem seems to affect the One Third Edition more than any other device although I seen my One XL and 720 power up on their own when left for a week - Mike

 

[safoocat]

turns itself on

My unit is the tomtom one 130s and yesterday was one week and yes it turned itself on.
It suprizes me that I was not able to find this complaint in the amazon reviews though I'll confess
to not reading every review for all the models either.

My unit doesn't have a reset hole and is reset by holding down the on button for 15 seconds. I did
that this morning and will let it sit on the shelf for a week to see if it turns back on next Saturday.

At I'm going back to Garmin. We have a Garmin NUVI 260
in the Prius and it works fine. The only thing I don't like about it is the alphanumeric keypad layout
and would prefer querty.
Michelle Ress

 

[beerman235]

Same 7 day power-up problem

Thanks for all the information about Tom Tom's power-up bug. I just tried it last week, and 7 days after I turned it off, it came on by itself! What a major flaw. I have the Tom Tom One third Edition so I have the reset switch on the bottom. The main thing is that at least I now know the rules.

I am not a lawyer and I hate frivolous lawsuits, but I would certainly sign-up to make Tom Tom replace all the worn out battries caused by their two year old software bug.

 

[canderson]

Just had a brain fart of massive proportions. Trouble is, I don't own one of the units that has the problem you are reporting, so I need your input.

Question for those that are experiencing this problem:

Does a TomTom that powers itself up in this fashion continue to run until the battery "gas gauge" drops to the bottom, forcing a shut-down, or by any chance are these units shutting themselves down at about a 50% capacity on the battery when this occurs?

If by ANY chance you are seeing the latter result (don't throw rocks), what TomTom may be doing is actually attempting to preserve your battery life, not kill it. Lithium polymer cells do NOT prefer to be stored at 100% charge for extended periods. ALL manufacturers of these cells will tell you that it they will not be used for an extended period, they should be stored at approximately 50% charge for best life of the cell/battery. I can envision code that intentionally detects long periods of disuse (call it a week) and enables enough circuitry to drain the battery a bit, leaving it powered up until the battery reaches about a 50% charge on the user's behalf, then shuts down. Hmmmph.. if someone hasn't patented that, they should.

Even if what I'm thinking could be the case isn't true (let me know what you're seeing out there, will you?), a word to those of you with TomTom units: if you plan to let it sit on the shelf for an extended period of time, don't fully charge it right before you do so. Leave it on and knock it back to about a half charge beforehand, and store it in a cool place. That combination provides the least degradation of the battery while it's sitting unused for extended periods.

 

[gatorguy]

When it comes on it pretty much drains the battery Canderson.

 

[canderson]

"Pretty much" as in "drains down the way it would if you were normally running it, the battery went into the "red" and you got the big warning just before it shut down for lack of juice" kind of "pretty much", or something in any way different from that?

 

[gatorguy]

The same as it would normally any other time you ran on battery alone IIRC. I can't check anymore for now and hopefully the TomTom I'll have coming won't have the same bug.

 

[Chireru]

by any chance are these units shutting themselves down at about a 50% capacity on the battery when this occurs?

Mine drains right out. Won't power on at all.

Furthermore, to get it to fire up again, I have to plug it in, wait a few minutes for it to put some charge in the battery, then turn it on. It won't actually turn on right away from a drained battery, even plugged in. All told, the whole process takes about 5 minutes every time I want to use it: plug it in and charge, turn it on, wait for the full boot, punch through the legal disclaimers, and find my position.

 

[canderson]

OK - many thanks for the feedback. Was hoping for something sensible in the firmware, but no luck. Not a bad feature idea if they could get it right - but I doubt they're that concerned over battery life - unlike we, the users!

The advice regarding long term storage of a TomTom still applies, though. Bad idea to park it in the closet for a couple of months starting out with a full charge.