Garmin touchscreen in cold weather

[gpsdork]

Hello all,

 

Considering upgrading to a Dakota 20 for hiking, kayaking, backcountry skiing, and the odd geocache. The Dakota appeals to me because it's small, has color screen, custom maps capability, and a much better battery life than my aging Geko 201.

 

De anyone have any real world experience indicating how well the touchscreen works in sub-freezing temperatures? I've written to Garmin, but no reply.

[+ecanderson]

De anyone have any real world experience indicating how well the touchscreen works in sub-freezing temperatures? I've written to Garmin, but no reply.

I've used mine at about 15F and it was OK, but the LCD will be a little bit sluggish as will any LCD at that temperature. Your bigger problem at those temperatures will be batteries. All battery chemistries suffer at those temperatures, and don't deliver anywhere near as much run time before they can't power the unit. I had my best cold weather results with NiZn cells, but Powergenix doesn't seem to have been able to get any traction in the consumer market, and has dropped that product. NiMH has the biggest problem at lower operating temperatures simply because they start out at a considerably lower voltage, and the GPS won't operate at much less than the NiMH nominal voltage. It all depends upon your needs and expectations.

 

Anyway, all of that to say the Dakota 20 itself seems to manage fine - but depending upon your use model in cold weather, you may find rechargables to be a problem unless you can keep the unit warm (inside pocket) between uses in really cold weather.

[+dfx]

Used Oregons 450 and 550 just fine in -20C, no problems at all with the touchscreen or anything else.

[eaparks]

+1 to ecanderson's comment. I have used my Oregon 400t mounted on the handlebar of my ATV out in 20-25 deg. F. for 8 hours of continuous use. Had no problems with using the touchscreen. It was the first time I had used the NiZn batteries (freashly charged) out in the cold and was amazed at how they lasted all day in that temperature, being exposed. Unit was never turned off. I personally like the NiZn batteries (2,500 mWh) and get considerably better life out of them than my Rayovac Hybrid (2,100 mAh).

[+dfx]

I can't say I've noticed any degraded battery life with any of my NiMH cells in the cold. The charge indicator will show a much lower charge than in warm weather and the "low batteries" warning will come on much soon, but you can just keep using the unit well beyond the warning. Eventually it's gonna turn off and it probably does that sooner than it would in warm weather, but I can't say the cold made a noticeable difference.

[yogazoo]

+1 to no issues in cold weather.

 

I've been out hunting in -20 F and ther were no issues with the touchscreen. The touchscreen interface was as responsive as ever BUT the redraw rate itself, being an electronic device, seemed a bit (not alot) sluggish. When the temperature drops the liquid in the LCD (as well as every other component) does not transfer electrons as efficiently as it would in a warmer environment. This however can be observed in most LCD's in most electronic devices.

[+rovers3]

My Oregon 400t takes forever to change screens after pressing the touchscreen in cold weather, I'm talking minutes, but I haven't seen that problem with my 450.

 

As for batteries NiMh, newly charged powerx 2700, 4 green bars, 1 green bar after 5-10 min but kept working fine all day. Haven't tried NiZn or lithium yet. As this one is almost over, maybe next winter.

[+ecanderson]

When the temperature drops the liquid in the LCD (as well as every other component) does not transfer electrons as efficiently as it would in a warmer environment. This however can be observed in most LCD's in most electronic devices.

Actually, electrons LOVE cold. Battery chemistry doesn't. Neither does the liquid material in an LCD display. As the viscosity of the LCD material increases due to cold, it takes longer for the applied voltage to force the LCD molecules into a polarized angle. It's a mechanical problem of liquid and cold together.

 

Most commonly used LCD material will operate, although very slowly, down to as low as -40F.

[+hurleyanne]

Considering upgrading to a Dakota 20 for hiking, kayaking, backcountry skiing, and the odd geocache. The Dakota appeals to me because it's small, has color screen, custom maps capability, and a much better battery life than my aging Geko 201.

 

De anyone have any real world experience indicating how well the touchscreen works in sub-freezing temperatures? I've written to Garmin, but no reply.

 

My Oregon's touchscreen works fine, and I've cached in temps colder than -30 C. However, I probably haven't had it outside for hours at a time at that temperature. My issue is more that with gloves my accuracy touching the screen goes way down and I end up needing to take a glove off and on to operate the GPSr. Bigger menu buttons would help a lot with that!

[yogazoo]

Actually, electrons LOVE cold. Battery chemistry doesn't. Neither does the liquid material in an LCD display. As the viscosity of the LCD material increases due to cold, it takes longer for the applied voltage to force the LCD molecules into a polarized angle. It's a mechanical problem of liquid and cold together.

 

I was referring to the semiconductors (processors/proccessing speed). The conductivity of semiconductors typically decreases with a decrease in temperature as build up of covalent bonds take place (the number of "mobilities" decreases with temperature). The relationship of temperature and semiconductors however can be non-linear and varies. In a conductor, agreed, the opposite is true. Free electrons move faster, creating more resistance / decreasing the current. In a conductor, this temperature relationship if often linear.

 

Discussion better suited for the Groudspeak Physics Forum.

 

Great info about the LCD properties. Since the LCD is the visual interface, when it slows down the unit appears to slow down to us regardless of internal performance.

Edited March 21, 2011 by yogazoo

[+ecanderson]

My Oregon's touchscreen works fine, and I've cached in temps colder than -30 C. However, I probably haven't had it outside for hours at a time at that temperature. My issue is more that with gloves my accuracy touching the screen goes way down and I end up needing to take a glove off and on to operate the GPSr. Bigger menu buttons would help a lot with that!

With a decent screen protector in place, I find that the closed end of my favorite caching pens do a lot better than my fingers, even when not in gloves.

[+ecanderson]

Great info about the LCD properties. Since the LCD is the visual interface, when it slows down the unit appears to slow down to us regardless of internal performance.

Indeed so. And the problem is that when cold enough, the material can't be (physically) flipped around nearly as fast as the processor can generate a new 'frame' of screen data. So while it's just a little annoying on 'static' screens (like keyboard entry or menu selections) it's pretty ugly with 'moving' screens like a scrolling map. Still, I find it to be pretty amazing that the stuff can be shifted into an optically polar position as fast as it can, even at room temperature.

 

The other problem that can occur with cold operation of GPS units shows up in half-light conditions (dawn, dusk, under heavy tree cover) when the backlight becomes especially important. Fluorescent backlights tend to run very inefficiently when they're ice cold - so users may tend to crank up the 'brightness', requiring more battery current.