-------------------- Tech Support Tips/Troubleshooting/Common Issues --------------------

Stress Tests

Looking at the product video, it looks like the minimum temperature of the heating pad 5x15cm was about ~120°F in open air and around ~130°F/140°F @ 5V and 0.6A. The maximum temperature of the heating pad can probably reach just over ~240°F-246°F @ 12V (based on the results of the smaller 5x10cm heating pad) and it will start warping the plastic. Any voltage higher will result in the pad breaking and damaging the product.

The product showcase tests the temperature output of the smaller 5x10cm [ https://www.sparkfun.com/products/11288 ] at different voltages. Here are some of the results:

~112°F @ 5V and 0.8A
~168.2°F @ 9V and 1.2A
~240°F-246°F @12V and 1.35A-1.5A for 4-6 hours, starts warping some damage
~350°F @ 17.7V and 1.61A, polyester melts, pad starts breaking down, damages the product

We can expect the 5x15cm heating pad to be around the same temperature or slightly above the the results of the smaller heating pad due to the bigger surface area for the 5x15cm heating pad.

Note: Keep in mind that the heating pad does not recover quickly when a cooler object touches the heating pad.

Battery Power

I had a customer use the 5x10cm heating pad for their project to heat a horse bit up. A 9V battery didn't work as well and it was getting hot to the touch. The heating pad was putting out less heat when the battery was overheating. He then used 4 AA batteries (for about 6V) in a battery holder https://www.sparkfun.com/products/12083 and didn't have a problem using it.

Additional Tutorials

Try looking at one of the tutorials that used the heating pad for a project => [ https://learn.sparkfun.com/tutorials/haptic-motor-driver-hook-up-guide#internal-trigger-mode-example-heated-foot-massager ]

Do you provide customized sizes for this heating pad?

I was looking for a heating source for my Arlo Camera's to keep them operating throughout the extreme cold winter nights here in Canada. I wrapped the heating pad around the outside of the camera and then slipped on the Arlo rubber skin to keep the heating pad in place. Plugged in the adapter into a timer which turned off and on every 30 minutes. This gives me the freedom to adjust the time depending on how cold the night temperatures might get. The camera's never shut down and no message "not operating - temperatures to cold". Products Purchased ... Heating Pad, DC Barrel Jack Adapter - Female and Wall Adapter Power 5V DC 2A (Barrel Jack)

So these act sort of like resistors, right? In that case, is the temperature proportional to the power (watts) or does it have some other strange behavior such as the voltage controlling the temperature and the current controlling the speed that it heats?

I tested two large heating pads, recently purchased and they do NOT meet published specs. Using a 5 volt supply capable of 2.4 amps output rating and used two separate thermometers (one digital with themocouple and the other glass mercury) and the maximum temperature reading I got after ten minutes was only 33 degrees Celsius. According to the temperature profile it should reach over 60 Celsius. A far cry from the published specs. The manufacturer in China probably stuck Sparkfun with some sub standard product. I used a 12 volt power supply which brought the temperature to 70 Celsius.

I once installed heating pads similar to these under motorcycle grips. They kept my hands nice and toasty when the mercury plunged. I preferred them to pricier integrated heated grips, as I could continue to use whichever grips I liked. This heating pad seems to be about the right size for that application. Attach to the bars with hairspray and add a rheostat to control the temperature. Take power from a circuit that is powered only when the ignition is on (e.g., brake lights), so you won't drain the battery if you forget to turn off the heating pads. If the bars are hollow, you could run the wires inside.

Wow, I can't believe Sparkfun sells this product. Not cool, guys!

Also, what's the current draw on this?

Hey, got a couple questions that I hope some of you can answer. I’m looking to install some of these in clothing, are they washable? Can I run these through a lilypad arduino board and a 5v battery with enough heat generated to feel through fabric? If anyone can answer either one of these questions that would be great, thanks!

"The fact that these are low power, flexible and draw little power makes them ideal for things like hand-warmers and other heated garments. Maybe hook up a microcontroller and some sensors and make your own climate-controlled hoodie?"

NO!...you mean: "these are great to keep your electronics warm on your HAB proyects... or Higher."

can i program this to turn on/off using a push button and arduino? Or is there a better method?

How easy would this be to control via, say, PID (PWM, of course)? I need this to be constant +- 0,25 degrees. I do have a precise sensor.

To clear up, I'm asking how proportional is the temperature to the voltage? Will its temp at, let's say, 50% PWM be constant?

Would running this through a washing machine cause any problems?

I am planning to use these in my gloves, would removing the plastic layers cause any damage? Would there be any danger of directly touching the internal conducting threads to skin when the plastic layers are removed? Thanks!

I'm thinking these might work as mirror heaters for my telescope to get rid of condensate. Looks like they might run a little hot though. Maybe hook two in series and run them off a 9v battery with a pot. Shouldn't be too hard to wrap a couple of these around the primary on the inside of the tube. An arduino might be a little overkill to regulate the temp though.

I found the WireKinetics 'Web site here:

[http://www.wirekinetics.com/en/products.php]

I looked around, but could not find a datasheet for these products; if they have one, it's apparently not available to the general public.

Is there any way of obtaining one, or at least getting a plot of current vs. expected temperature?

Thanks...

I am thinking about using two of these to warm a solar battery bank in an insulated box. I live in Michigan and my battery bank is in a detached garage where temp can drop below freezing quite often. I have a DC charge controller and am thinking about wiring two of these pads off the 3V DC port. The controller has direct DC outputs and should recharge the less than amp draw. Any thoughts? I am also looking for a dc temp controller to automatically monitor the temp so I am not drawing power unless needed. I am not sure if this type of temp controller for dc exists. Any help is appreciated.

Could we get a measurement on the weight and resistance of this product?

The first thing that came to mind for me was heated seats in my car. Just peel back the fabric and tape these things down. My question is whether these could hold up to both the direct pressure and the rubbing involved. Could I get an answer to how durable these things are? Thanks.

How exactly do these work? I'm trying to figure out if I could create a temperature control using a variable resistor. Do these generate heat through resistance, or some other method?

is it possible to waterproof this heater?

Can someone tell me at what temperature the pad is irreversible damaged? (like in the video?)

Thanks!

Can someone please measure the resistance of the heating pad? That way I and everyone else can calculate the current and wattage at various voltages. The 'warmup profile' is interesting but can't really be used to figure out how it'll behave in different applications. The video gives a coarse way of calculating the resistance by stating the current draw at 5v... but I'd rather just know the specs of this thing.

I'm wondering how well this would work as a heating element for a RepRap build platform. Are they available (anywhere) in larger sizes? Say 20x20cm?

My thought on these is to use as a Lipo battery warmer for my weather station on the roof in the winter time.