Car charger question?

[Smokiewolf]

Because the jumps/dips in amperage could damage the charger, I would assume... But I've been using mine in my truck, even when cranking, and have had no issues. *shrug* It's probably just their due diligence... Just like the No Cellphones signs in hospitals. There's been no issues with cellphones and hospital equipment (so I have read) since the old 3watt bag phones. It's there "Just in case".

Yeah, and the ban on airplanes, too! I have been charging mine in vehicle more often than at home also.

 

[danjreed]

Can't charge a bat from dc only from AC

What?!

That makes no sense..

All DC batteries are charged with DC.

 

[tomlouie]

If your car has a cig outlet that's hooked directly to your car battery (instead of powered on only when your car key is turned), then I can see that it's possible that if you left your TomTom plugged into your car for a long time, it could completely drain your cat battery.

But that's very very unlikely. Almost every cig outlet I've ever used gets switch off when the car key is removed.

 

[8alchemist8]

Granted i only got my tomtom over the weekend, I've been charge it off the USB so far, however I've also gotten a good first charge off my car plug. With the USB's just remember -it's important to look at what your USB port comes from. The USB bus standard current is 500mA, however most self-powered hubs, on-keyboard, on-monitor hubs can't manage a full amperage draw - or if they can, it would only be for one device. Anything after that is questionable. Hence the availability and usefullness of the powered hubs. If your Hub, or the device with the built-in hub (Keyboards, monitors, etc) has a power cord, it's probably powered. Companies like Targus and Belkin offer USB hubs that DOUBLE the standard available amperage to 1000mA and even offer hubs with ports that are always powered even when the computer is off. I have a Targus model that I typically use to charge my tomtom and my phone. So far so good.

My one question, however, is this: Does the tomtom smart charge? In other words, does it cease charging when it's fully charged? The reason I ask is that even with Li Ion and NiMH batteries, if you keep them plugged into a charging source for prolonged periods of time it can "cook them out" effectively destroying them. It can also blow out the transformer in the charger. I've killed a couple "wall wart" type chargers and the battery in my Romba this way. I'd hate to do this to my tomtom and will have to be more diligent in managing the device if it is a "dumb-charger".

 

[flyer1024]

My one question, however, is this: Does the tomtom smart charge? In other words, does it cease charging when it's fully charged?

With both the car charger and with the aftermarket AC charger I bought (el cheapo model) the unit stops charging once full charge is reached.

to check what it is actually doing, look at the battery status icon. If it is on the charger and actually charging, you will see the word "charging" under the battery icon. It disappears when the unit is fully charged or when you unplug the charger if it isn't.

 

[ssttnn66]

Almost every cig outlet I've ever used gets switch off when the car key is removed.

My 2002 Pontiac GrandPrix keeps its cig lighter on all the time. I had to jump start the battery after not starting the car for 3 days and leaving the TT on. I also have a '98 chevy van that the cig lighter is always on too. The van, however, has a built in system that shuts off power after a while (don't know how long) if there is a continuous drain on the battery to prevent complete battery drainage.

 

[ShadowDemon]

Tomtom One 3rd gen Car charger problem

I had a problem over the weekend charging the Tomtom using the car charger. It had previously been charged with a USB/computer connection and was fully charged to begin with.

After a couple hours, the Tomtom was showing a weak battery even though it had been plugged into my car's lighter socket the entire time. I pulled the fuse and it was fine (checked with continuity tester). Even the green light on the charger plug along with the light on the Tomtom was lite, but the battery indicator continued to flash. Eventually the unit just turned off!

Since I was relying on this to get me to San Francisco from L.A., I pulled over and directly connected the Tomtom to my computer where I got a partial charge and continued my trip by turning it off frequently with the weak battery.

Needless to say, the Tomtom wasn't charging with the included car charger (status window didn't say charging and battery indicator continued to flash). It would charge my USB blackberry so I know it WAS getting power to the plug.

Has anybody heard of this issue?

Thanks in advance... especially considering this is my first post.

 

[gn2]

I had a problem over the weekend charging the Tomtom using the car charger. It had previously been charged with a USB/computer connection and was fully charged to begin with.

After a couple hours, the Tomtom was showing a weak battery even though it had been plugged into my car's lighter socket the entire time. I pulled the fuse and it was fine (checked with continuity tester). Even the green light on the charger plug along with the light on the Tomtom was lite, but the battery indicator continued to flash. Eventually the unit just turned off!

Since I was relying on this to get me to San Francisco from L.A., I pulled over and directly connected the Tomtom to my computer where I got a partial charge and continued my trip by turning it off frequently with the weak battery.

Needless to say, the Tomtom wasn't charging with the included car charger (status window didn't say charging and battery indicator continued to flash). It would charge my USB blackberry so I know it WAS getting power to the plug.

Has anybody heard of this issue?

Thanks in advance... especially considering this is my first post.

You have just described my exact problem, can anyone point to a solution ??

I realize this is an old thread, but there was no follow up to this question and I would REALLY like to solve this problem, even with a "workaround" if anyone has one...

 

[dhn]

If the unit is under warranty, you should be able to get a replacement Car Charger.

If not, well Best Buys or Future Shops carry gps car chargers, usually for less than the price from TT directly.

Just a thought.

 

[gn2]

If the unit is under warranty, you should be able to get a replacement Car Charger.

If not, well Best Buys or Future Shops carry gps car chargers, usually for less than the price from TT directly.

Just a thought.

I appreciate the suggestion, however, I have tested the car charger by connecting it to my Blackberry, and it charges it just fine. The Blackberry charges with three different car chargers, whereas the TomTom won't charge with ANY of them, in the car. However, the TomTom charges in the house, either from a normal computer USB connection, or from the TomTom brand home charger perfectly...

If I KNEW in advance, yet another car charger would solve the issue, I would run out to get one, but it seems unlikely that buying just any charger will be the solution.

On the front of warranty replacement of my current car charger, HOW does one go about that ? I've searched for information about how to take advantage of the warranty and haven't found much information...what I've seen suggests it will cost at least the amount of shipping to make any warranty claim. Considering the increase in postage rates, it would likely be less expensive to purchase a charger from ebay...BUT, if the charger is the issue, then it must have to comply with very, very, very narrow specs to "work" with the TomTom since it will charge my Blackberry just fine, but won't charge the TomTom at all...

 

[dhn]

Have you been in touch with CS at 866-486-6866 about this problem?

 

[gn2]

Have you been in touch with CS at 866-486-6866 about this problem?

Thank you very much for the phone number, I honestly hadn't been able to find that anywhere. I did call, they're sending me a new car charger without me having to send in my present one.

So far, I'm impressed with how TomTom responded to me, much better than I was expecting.

Here's hoping the new charger does the trick.

 

[Michael Quinlan]

I see this thread was revived just in time for me to jump in. I'm going away tomorrow for about 1 week, and rather than dismantle my neatly tucked wiring in my truck, I was hoping to use a generic USB car charger with a mini-USB cable to operate/charge my 740. Knowing that the TomTom-branded car charger is rated at 1.2 amps (I think the charger for my 920 had a 2a fuse), and my generic charger is rated at 1 amp, I thought I might have a problem with my battery not charging, or possibly discharging, while using my 740 with the generic charger.

I last night and this morning I purposely left my 740 powered on (battery only) to discharge the battery. With the battery low (but no flashing warning on the battery indicator) I set out on a 75-80 minute trip using the generic charger. When I returned home I turned off the 740 and brought it inside. A few hours later I tried to make a map correction that I had marked on my trip, only to find that the battery indicator was flashing a low warning.

Does anyone know what power a 740 (or other TomTom unit) draws in order to operate and/or charge properly?

For now I have untucked the wiring in my truck and will be bringing the TT-branded charger with me just in case.

 

[canderson]

It CANNOT draw more than 500mA or it would not be possible to both charge and operate in the docking station. Nothing is permitted to expect more than 1/2 amp from a single USB port on a PC. Them's the USB rules.

 

[oil710]

There are many posts describing differing opinions as how to (or not) charge a TomTom.

The AC adapter you are using will be producing (via mini-usb connection) a PULSED DC current at about 5 volts. This pulsing will occur between 50 and 60 times a second (depending on which country you are in).

The power from a USB cable from a computer will also likely be pulsed, but not necessarily. It depends on the internals of the voltage regulator within the PC/Laptop.

The power from the cigarette adapter within a vehicle will (most likely) be a continuous 5v DC supply, as it is being sourced from a straight DC source( the car/truck circuitry). To get the output down from 24/12v the vehicle adapter may be using several methods, one of which simply leaks the extra voltage through a resistive circuit, so the output will be around 5v continuous DC. Some may be a bit smarter, and use a small micro-chip to pulse the incoming power, run it through a Triac, and just deliver 5v Pulsed.

So, for adapters, it all depends on the one you use. To see the output of yours, you would best hook it up to an oscilloscope and look at the wave patterns produced.

Now your TomTom device internal circuitry is most likely NOT running on a 5v battery. It may have batteries linked in series to provide 2.8v , 4.2v, 5.6v or whatever. I have never pulled one apart. So, its internal charging circuit _MAY_ be best served by pulsed DC. But either way, it should re-charge via pulsed OR continuous DC. I know mine does!

OIL710

 

[canderson]

There are many posts describing differing opinions as how to (or not) charge a TomTom.

The AC adapter you are using will be producing (via mini-usb connection) a PULSED DC current at about 5 volts. This pulsing will occur between 50 and 60 times a second (depending on which country you are in).

Lord - sounds like a circa 1920 half-wave analog supply with poor output filtering. What you describe would cause a lot of non-battery devices to reset. Nobody designs anything like this.

Even an analog supply would filter the ripple to an absolute minimum with adequate capacitance. A switching supply (as 99.9% of these are these days due to efficiency requirements) operates at much higher frequencies AND filters out the remaining ripple.

What you are describing does not exist.

The power from a USB cable from a computer will also likely be pulsed, but not necessarily. It depends on the internals of the voltage regulator within the PC/Laptop.

The usb.org ripple spec on a host side USB connection makes the use of the word "pulse" a non-sequitur.

The power from the cigarette adapter within a vehicle will (most likely) be a continuous 5v DC supply, as it is being sourced from a straight DC source( the car/truck circuitry). To get the output down from 24/12v the vehicle adapter may be using several methods, one of which simply leaks the extra voltage through a resistive circuit, so the output will be around 5v continuous DC. Some may be a bit smarter, and use a small micro-chip to pulse the incoming power, run it through a Triac, and just deliver 5v Pulsed.

??? Leaks the extra voltage through a resistive circuit ??? Think about that for just a minute -- you'd be talking ~500mA x (12V - 5V) = 3.5W. Besides, the current draw of the TomTom varies with use (e.g., screen brightness, on/off, whatever). You couldn't use a simple resistive voltage drop and have anything close to a stable voltage output. I can't speak for how clean the DC-DC converter in the auto adapter is, however. I'll peek at that sometime.

Now your TomTom device internal circuitry is most likely NOT running on a 5v battery. It may have batteries linked in series to provide 2.8v , 4.2v, 5.6v or whatever. I have never pulled one apart.

The batteries in these things are 3.7V lithium polymer packs. The internal chargers incorporate DC-DC conversion from ~5V input to 3.7V output on the charging side. LiPo starts with a constant voltage charge.

 

[oil710]

Lord - sounds like a circa 1920 half-wave analog supply with poor output filtering. What you describe would cause a lot of non-battery devices to reset. Nobody designs anything like this.

OK, so I am an old f*rt, please be gentle . I did study some electronics about 50 years ago. Seems I need to take a refresher course.

The way you have modernised my view of power converters enlightens me. Thanks

OIL710

 

[Head_Unit]

First off, the USB spec is indeed tight. So a PROPER device would maintain almost exactly 5V regardless of whether the car battery is at 10V or 16V or whatever fluctuation.

Now, is every cheap little device from China or wherever actually 100% compliant to that? Hmpf, maybe not.

It would require a good regulator, and obviously due to cost that may not happen every time. That's why some chargers will work better than others especially for sensitive devices like iPhone.

TT support told me that even when you turn the unit off, it is not truly off, it is sleeping. I might actually believe that-it would keep it ready to boot a LOT faster than from true off. Then, the nice fellow said they recommend to always leave it plugged in-I presume so that, since it is draining a bit while the car sits, it recharges while you drive.

BUT...you can see a zillion laptops on Craigslist, almost all with dead batteries due to being constantly topped off which does apparently "cook" them as posted above. So I still unplug the TT occasionally until I see the low battery indicator, then plug it back in.

P.S. Hardly any cars maintain the lighter socket live when the car is locked --> if the car sits for a long time, the TT battery would drain dead, and when you do start the car it will have to charge enough to wake up and then reboot from scratch and then reacquire the entire GPS satellite constellation. That whole process could take 5-10 minutes.
Moral: don't leave the TT in a long-parked car, bring it inside and check the charge periodically.

 

[eldorado]

I certainly disagree with TT-Lady, I run my OneXL all the time on the motorcycle or car plugged into the charger for days at a time and if I unplug and check the battery it is always at full charge, so the car plug/charger does work, in my experience and mine is 3yrs old...........

 

[mvl]

Tomtom's shut off after 3 minutes of non-use when plugged into a computer, supposedly to charge faster since computers only spit out 500mA.

Tomtoms will take a full 2A from their car/wall chargers and charge much faster. I've seen many cell phones do the same thing, so it may be non-USB-compliant, but it's common.

The 740 does burn through batteries, I'm sure its cellular modem is the culprit. I doubt it uses sustained high power levels, but I'm sure it needs it when it does the initial cell tower connect. I don't know what the minimum power is, as I leave it charged all the time, but I'd bet that 1amp is sufficient as long as it's continuously plugged in so it has enough reserve for peak usage.