LCD Screens in cold weather

[+user13371]

Lifted from another thread (to avoid derailing the original conversation) ...

 

Briansnat recently remarked about his Delorme PN-40...

... I just discovered this weekend. The screen drawing is glacially slow when it gets a bit cold. Morning temps were in the high 30s/low 40s and I couldn't believe how long it took to draw screens. When the weather warmed during the day it was fine. The problem appeared again the next morning when it was cold and it was fine again once things warmed up. So it doesn't seem to handle cold very well.

Some folks have replied this is "normal" because all LCDs are sensitive to cold and will slow down. But I've never had one become noticeably slower "in the high 30s/low 40s."

 

Anyone else seen this kind of problem with any GPSR, not just DeLorme? How low can you go?

Edited September 12, 2009 by lee_rimar

[NordicMan]

Do you suppose the problem is with the cold LCD or the cold batteries ?

 

If a Delorme owner would like to do a test, try 1) stick your GPSr in the fridge for a few hours. Take it out & try it.. is it sluggish? Next:

 

2) pull the batteries out & stick the GPSr in the fridge. After a few hours take it out & pop in the warm batteries. Try it,, still sluggish?

[+user13371]

I'll probably do some refrigerator testing myself later, if I have time. But whether it's batteries or LCD, the temperature Briansnat reported seem more weird. High 30's to low 40's? I wouldn't even bother wearing gloves.

 

Over there...

 

http://forums.delorme.com/viewtopic.php?t=12964 -- old discussion

http://forums.delorme.com/viewtopic.php?p=131930 -- revisited today

 

are some first hand experiences, and published specs.

 

---

Edit to add: My PN-40, w/o batteries, is sitting in the freezer. I'll come back in a few hours and see how it works.

Edited September 12, 2009 by lee_rimar

[+TotemLake]

Do you suppose the problem is with the cold LCD or the cold batteries ?

 

If a Delorme owner would like to do a test, try 1) stick your GPSr in the fridge for a few hours. Take it out & try it.. is it sluggish? Next:

 

2) pull the batteries out & stick the GPSr in the fridge. After a few hours take it out & pop in the warm batteries. Try it,, still sluggish?

I never saw the sluggisness and I was in weather much colder than Briansnat was. When deciding on the direction to take, a 60 was still pointing in the wrong direction when I showed the user which way we should go and when we turned to view the trail, the map responded accordingly with no discernable sluggisness being complained about. This GPS sits exposed on my shoulder when put away. It isn't North Pole temps, but when you have to keep your insulated water tube tucked inside your jacket so it will remain usable and not freeze up on you. That's cold. I use lithiums. So I would have to point at an inferior battery type as the culprit and not the screen.

[+user13371]

...I would have to point at an inferior battery type as the culprit and not the screen.

That's a hypothesis we can test.

 

- What affect does low temperature have on "inferior batteries"? Reduced voltage?

- Is the PN-40 known to slow down screen redraws at low voltage?

[JDiablo]

...I would have to point at an inferior battery type as the culprit and not the screen.

That's a hypothesis we can test.

 

- What affect does low temperature have on "inferior batteries"? Reduced voltage?

- Is the PN-40 known to slow down screen redraws at low voltage?

You could always stow your gps overnight in your freezer and check it in the morning, no need to wait until winter

[scotthsi]

You could always stow your gps overnight in your freezer and check it in the morning, no need to wait until winter

 

Excellent way to crack the screen, too.

[JDiablo]

You could always stow your gps overnight in your freezer and check it in the morning, no need to wait until winter

 

Excellent way to crack the screen, too.

It the unit is rated at that temperature then it shouldn't be a problem.

[+TotemLake]

...I would have to point at an inferior battery type as the culprit and not the screen.

That's a hypothesis we can test.

 

- What affect does low temperature have on "inferior batteries"? Reduced voltage?

- Is the PN-40 known to slow down screen redraws at low voltage?

It is possible. Not all batteries are created equal. Some are designed for burst output where others are designed for specific and steady voltage and some are just plain bad. I've learned to stay away from certain brands just based on my personal observations during usage.

[+Pax42]

I've tested many LCDs at temperatures from -45C to +75C. Once below 0C LCD performance will start to degrade but I'd say you probably won't see any noticeable sluggishness until -5C and below. I've seen LCDs still operational (although very slow) at -35C. I've never seen one crack just because it was that cold. Backlight performance degrades with cold if the display uses a CCFL backlight. CCFL tubes are very inefficient when cold which is why we design heaters into aerospace LCD displays.

[+dakboy]

...I would have to point at an inferior battery type as the culprit and not the screen.

That's a hypothesis we can test.

 

- What affect does low temperature have on "inferior batteries"? Reduced voltage?

Briansnat posted that he was using alkaline batteries. I think it's fairly common knowledge that alkalines get really bad when the temperature drops. Ever take a Walkman (yes, an old tape-playing Walkman) outside in the winter? If you don't keep it inside your jacket, it starts acting like the batteries are dying (plays the tape slower & slower).

 

My family has kept alkalines in the fridge for as long as I can remember to lengthen their shelf life.

[+user13371]

Right, well here's the result of the first part of my freezer test of the PN-40; chilling just the device but not the batteries for several hours: No difference. The screen might have taken slightly longer to come on, but no obvious slowdown or problems with brightness.

 

Next test, a little later -- will be with chilled batteries.

 

I have no doubt that cheap batteries suffer from cold, but I still can't get that to fit Briansnat's observation of the screen redraw slowing down. A GPS is not a tape player -- low batteries shouldn't make it slow down. I'd expect it to give a low-battery warning or just shut off.

 

Unless it works like some of the gadgets in Terry Pratchett's Discworld? A small demon lives inside the GPS and paints the maps for you... but the poor little imp slows down when tired, hungry, or cold

Edited September 13, 2009 by lee_rimar

[+Searching_ut]

I don't know if a freezer would get the units cold enough to see what happens. I've used both grayscale and coler etrex units outside in the winter, and find they're good to a little below zero fareheit most of the time if you use lithium batteries. Somewhere around zero or a little below, the sreen will get really sluggish, and start doing strange stuff where only parts of it update and stuff like that. The unit will keep recording good tracks though long after the display stops working. On the other end of the spectrum, having taken the Grayscale units into the desert many a time, I can report that direct hot sun on the display will cause the constrast to change to the point you can't read the screen anymore, and that with eTrex units or a G-III at least you can't adjust the constrast enough to make them useable. I haven't observed similar behavior with color units yet though.

 

On the Teton snowshoe backpacking trip I went on where it got cold enough to cause my VistaC display to fail, I just used the lanyard and kept it inside my coat worn around my neck most of the time. You can then pull it out and use it for a considerable amount of time before it gets cold enough to cause any problems. Other than the rare occasion, most of time though I don't expose my units to the cold for a long enough period of time to experience problems. As I age, I find I'm a lot less likely to expose myself to that sort of condition. (Who knows, maybe it's wisdom)

[+user13371]

I don't know if a freezer would get the units cold enough to see what happens.

The post that started this discussion was Briansnat observing (off in a different thread) a dramatic slow down when the temps were in the high 30's to low 40's. Not very cold.

 

If I can't duplicate the result with my freezer then then there's something wrong with his particular GPS or his batteries. And I still don't know how "bad batteries" would cause the display to slow down -- as opposed to some other malfunction or a simple "low power" shutdown.

[John E Cache]

Liquids freeze. My father bought a Sharp LiquidCD TV for his summer cabin in Minnesota and now found out that he has to take it to Florida for the winter because Sharp says the LCD can not be stored at colder than -4F.

[+user13371]

Welll - either Brian's got something wrong with his PN-40, or there's some other info missing from his report. Various batteries (a couple sets different sets of alkalines, different brands and charge levels) left in the freezer overnight with the GPS, no problem seen.

 

The high-30's to low-40's he spoke about shouldn't have caused the problem he described.

Edited September 13, 2009 by lee_rimar

[+PDOP's]

Any reports of how touch-screens are effected by freezing temperatures? Do they still respond as quickly?

[+Pax42]

The simple 4-wire resistive touch screens (without special films) that are used on these devices are not really affected by cold temps.

[+dakboy]

The simple 4-wire resistive touch screens (without special films) that are used on these devices are not really affected by cold temps.

iPhones, OTOH, require sensing the heat of a bare finger & have a capacitive sensor layer. Won't work too well in the winter north of the Mason-Dixon line.

[+PDOP's]

The simple 4-wire resistive touch screens (without special films) that are used on these devices are not really affected by cold temps.

iPhones, OTOH, require sensing the heat of a bare finger & have a capacitive sensor layer. Won't work too well in the winter north of the Mason-Dixon line.

Thanks. I was wondering about the Colorado/Oregon/Dakota screens?

[+Pax42]

The simple 4-wire resistive touch screens (without special films) that are used on these devices are not really affected by cold temps.

iPhones, OTOH, require sensing the heat of a bare finger & have a capacitive sensor layer. Won't work too well in the winter north of the Mason-Dixon line.

I actually cleared up the same misconception for TL a few months back on the Delorme forums. Capacitive touch screens, or more speciically "projected capacitive" in the case of the iphone, do not sense heat. A projected capacitive screen detects a change in the electric field near its surface. Haven't used one in cold temps myself but there should be little to no effect.

[+dakboy]

The simple 4-wire resistive touch screens (without special films) that are used on these devices are not really affected by cold temps.

iPhones, OTOH, require sensing the heat of a bare finger & have a capacitive sensor layer. Won't work too well in the winter north of the Mason-Dixon line.

I actually cleared up the same misconception for TL a few months back on the Delorme forums. Capacitive touch screens, or more speciically "projected capacitive" in the case of the iphone, do not sense heat. A projected capacitive screen detects a change in the electric field near its surface. Haven't used one in cold temps myself but there should be little to no effect.

OK, so the heat part is wrong, but it still requires a bare finger. There are "special gloves" which let you expose your fingertip to use it.

 

Thanksgiving through mid-March, an iPhone would be a poor choice for caching in my neck of the woods, unless you enjoy frostbite.

Edited September 13, 2009 by dakboy

[+Searching_ut]

The simple 4-wire resistive touch screens (without special films) that are used on these devices are not really affected by cold temps.

iPhones, OTOH, require sensing the heat of a bare finger & have a capacitive sensor layer. Won't work too well in the winter north of the Mason-Dixon line.

I actually cleared up the same misconception for TL a few months back on the Delorme forums. Capacitive touch screens, or more speciically "projected capacitive" in the case of the iphone, do not sense heat. A projected capacitive screen detects a change in the electric field near its surface. Haven't used one in cold temps myself but there should be little to no effect.

OK, so the heat part is wrong, but it still requires a bare finger. There are "special gloves" which let you expose your fingertip to use it.

 

Thanksgiving through mid-March, an iPhone would be a poor choice for caching in my neck of the woods, unless you enjoy frostbite.

 

Battery life is also going to be an issue at those sorts of temperatures. Lithiums will work to remarkably low temps, but they don't have anywhere near the capacity, meaning if the unit ate batteries fairly quickly before, it's going to kill them really fast in the cold. On the plus side, there will still be usable power in them should you wait till spring to try and find your way back to wherever it is you're headed.

[JDiablo]

Right, well here's the result of the first part of my freezer test of the PN-40; chilling just the device but not the batteries for several hours: No difference. The screen might have taken slightly longer to come on, but no obvious slowdown or problems with brightness.

 

Next test, a little later -- will be with chilled batteries.

 

I have no doubt that cheap batteries suffer from cold, but I still can't get that to fit Briansnat's observation of the screen redraw slowing down. A GPS is not a tape player -- low batteries shouldn't make it slow down. I'd expect it to give a low-battery warning or just shut off.

 

Unless it works like some of the gadgets in Terry Pratchett's Discworld? A small demon lives inside the GPS and paints the maps for you... but the poor little imp slows down when tired, hungry, or cold

No cracked screen? Maybe the small demon inside has a heater.

[+user13371]

Maybe the small demon inside has a heater.

Would be quite an advance in the Discworld. Imps work inside of cameras and "personal disoganizers" (equivalent of a PDA), but I don't think there's a DPS (Discworld Position System) yet.

 

Sadly, Terry Pratchett has Alzheimer's, so it's possible Discworld technology might never advance much further than the clacks.

[JDiablo]

Maybe the small demon inside has a heater.

Would be quite an advance in the Discworld. Imps work inside of cameras and "personal disoganizers" (equivalent of a PDA), but I don't think there's a DPS (Discworld Position System) yet.

 

Sadly, Terry Pratchett has Alzheimer's, so it's possible Discworld technology might never advance much further than the clacks.

I think I have a team of them in my Toughbook .