EUC Cold Weather Thermal Pad

[Rehab1]

As winter approaches we all know that Lithium Ion batteries hate cold weather which affects the  overall performance of our wheels while diminishing your ride time. 

I decided to custom fabricate a thermal pad for EUCs that will hopefully transfer enough heat through the shell to help maintain battery efficiency. This EUC Thermal Pad can be adapted to various EUCs but I chose to first experiment with the 16X.  
 

I started the whole process by completely disassembling a back support with heating elements incorporated into the fabric.  The unit is powered by a slim rechargeable battery pack

(See battery pocket next to the left of the green on/off switch.)

Here I performed an autopsy on the back warmer. 

Next I cut down the thermal pad and rerouted the wires.

I then stitched a waterproof thin plastic membrane and binding over the device while carefully avoiding the embedded heating elements.
 

Once the thermal device was complete I attached a bluetooth temperature data logger on top of the pad and then proceeded to turn everything on.

Awesome! No flames! None of the wires or heating elements were compromised during the sewing/assembly process. 
 

 Below is a graph taken today of the bluetooth data logger depicting a 12 minute episode of the EUC Thermal Pad gaining temperature. It takes a few minutes for the thermal pad to initially warm up. It reached 97 degrees F  (36 degrees C).  

 

Here I’ve attached the EUC Thermal Pad to my 16X under the handle. It is held in place with Velcro. 

 

 

Once it turns cold outside I’ll report back on the functionality of the device. Hopefully I’ll be able to draw some comparisons between the internal temperatures of the 16X and the amount of influence the thermal pad will have on it’s ability to transfer heat inside. 
 

[EUC Custom Power-Pads]

You are joking? 

[null]

@buell47 Electric cars keep their battery at efficient temperature through heating, why not a euc.

There are simple silicon heating pads of all sizes with integrated temperature probe that could probably be mounted inside the shell: 

https://www.google.com/search?q=silicone+heat+pad&tbm=isch&ved=2ahUKEwjZloCxuN_lAhUG0YUKHdT8BZYQ2-cCegQIABAC&oq=silicone+heat+pad&gs_l=mobile-gws-wiz-img.3..0j0i8i30l2j0i24l2.7052.11934..12408...0.0..0.64.865.19......0....1.........41.1LRGfA8tvHg&ei=GufHXdmhLoailwTU-ZewCQ&bih=454&biw=320&client=safari&prmd=sivn

[Rehab1]

1 hour ago, buell47 said:

You are joking? 

Possibly. Many of my EUC experiments have been jokes (just ask around) but if it turns out that the thermal pad produces enough heat transfer to warm the inner shell and subsequently the batteries then I’ll be 2 for 10. 
 

 

[Planemo]

I think it will struggle with being mounted externally, but I'm happy to be proved wrong

[Ben Kim]

ha, whatever gains you get from lower battery sag you’ll lose from powering that thing! 

Just take it easy in the winter and take care of your battery by not charging it outdoors in the cold. Winter will be over before everyone knows it! 

[EUCGUY]

On 11/8/2019 at 10:23 PM, Rehab1 said:

As winter approaches we all know that Lithium Ion batteries hate cold weather which affects the  overall performance of our wheels while diminishing your ride time. 

I decided to custom fabricate a thermal pad for EUCs that will hopefully transfer enough heat through the shell to help maintain battery efficiency. This EUC Thermal Pad can be adapted to various EUCs but I chose to first experiment with the 16X.  
 

I started the whole process by completely disassembling a back support with heating elements incorporated into the fabric.  The unit is powered by a slim rechargeable battery pack

(See battery pocket next to the left of the green on/off switch.)

Here I performed an autopsy on the back warmer. 

Next I cut down the thermal pad and rerouted the wires.

I then stitched a waterproof thin plastic membrane and binding over the device while carefully avoiding the embedded heating elements.
 

Once the thermal device was complete I attached a bluetooth temperature data logger on top of the pad and then proceeded to turn everything on.

Awesome! No flames! None of the wires or heating elements were compromised during the sewing/assembly process. 
 

 Below is a graph taken today of the bluetooth data logger depicting a 12 minute episode of the EUC Thermal Pad gaining temperature. It takes a few minutes for the thermal pad to initially warm up. It reached 97 degrees F  (36 degrees C).  

 

Here I’ve attached the EUC Thermal Pad to my 16X under the handle. It is held in place with Velcro. 

 

 

Once it turns cold outside I’ll report back on the functionality of the device. Hopefully I’ll be able to draw some comparisons between the internal temperatures of the 16X and the amount of influence the thermal pad will have on it’s ability to transfer heat inside. 
 

I believe the motor itself with all that metal will radiate the coldness into the batteries more than that pad can heat it. Some insulation as a barrier around the packs or heated foil directly with insulation on the outside. That would require less energy to maintain a set temperature. 😊

[Rehab1]

3 hours ago, Planemo said:

I think it will struggle with being mounted externally, but I'm happy to be proved wrong

 

8 minutes ago, Ben Kim said:

ha, whatever gains you get from lower battery sag you’ll lose from powering that thing! 

You guys are spoiling all of my fun. You both may be right. 

The temperature is suppose to drop this afternoon so I’m currently acclimating the Z10 outside (yes...I switched wheels). 
 

Currently it’s 34 degrees F outside at 1:05 pm

 

Z10 sitting alone with thermal pad and data logger ready to go this evening. 

 

Current Z10 battery temperatures at 1:04  Bat 1

Bat 2

I’m not concerned if it works or not. It’s just a fun project. Only a few hours labor and very little cost. We’ll find out tonight. 

 

[Planemo]

You might want to put the heater where the battery is 

[Ben Kim]

@Rehab1

In past winters, (this is on a Dualtron, not an EUC) Up to 45 F, battery sag/loss was minimal. However, around 30 F I saw a loss of range of around 15% with less peak power.

Battery would also take longer to get back to resting voltage. With that said, it really depends on how extreme the temperatures are outside, if temps approach the teens and zeroes, I would say you shouldn’t even be riding outside!

[Rehab1]

20 minutes ago, EUC GUY said:

I believe the motor itself with all that metal will radiate the coldness into the batteries more than that pad can heat it. Some insulation as a barrier around the packs or heated foil directly with insulation on the outside. That would require less energy to maintain a set temperature. 😊

Unfortunately I’m not interested in tearing into the wheel for this experiment. If I can maintain the temperature of the packs without any significant decrease over time, say 90 minutes, then I’ll be happy.
 

I was able to keep both battery pack’s temperatures at 59 degrees F earlier when it was 34 degrees outside but the wheel was only outdoors for an hour. I want the entire wheel to acclimate outside for a few hours so the battery temps and outside temps match up before I begin testing. 

 

 

 

[Ben Kim]

@Rehab1

Looks like my unscientific experience is pretty much in line with this article. Capacity loss is assuming the battery stays at these operating temperatures, which they do not once they are being discharged. If anything, keeping your wheels in a warm environment then riding as normal will keep the power loss at a minimum in the winter.

https://batteryuniversity.com/learn/article/discharging_at_high_and_low_temperatures

With that said, don’t charge your batteries outdoors in winter, but don’t worry too much about battery temps while being ridden. 

[EUCGUY]

12 minutes ago, Ben Kim said:

@Rehab1

Looks like my unscientific experience is pretty much in line with this article. Capacity loss is assuming the battery stays at these operating temperatures, which they do not once they are being discharged. If anything, keeping your wheels in a warm environment then riding as normal will keep the power loss at a minimum in the winter.

https://batteryuniversity.com/learn/article/discharging_at_high_and_low_temperatures

With that said, don’t charge your batteries outdoors in winter, but don’t worry too much about battery temps while being ridden. 

Last few weeks before winter came, i had my wheels outside at work for 7 hours in 0 / 4C temps.
The issue is the voltage sag. 50% changed pack isnt enough when that cold as any hard leaning will trigger the low voltage warning. happened multiple times.

Id say for safety, keeping batteries warm is best.

[Rehab1]

4 hours ago, EUC GUY said:

Id say for safety, keeping batteries warm is best.

Totally agree. I never leave my wheels outside.....except for this test. 

I left the Z10 outside this afternoon for 5 hours so both the temperature of the data logger and the wheel would acclimate. I need accurate quantifiable data of both both to test the thermal pad effectiveness. 

Unfortunately both of the Z10’s battery temperature sensors are off by over 9 degrees F.  The data logger is running at 44 degrees F ( 6.6 C) and the Z’s batteries are at 53 degrees F (11.6 C) . 

 Temperature Data Logger = +/- 44 degrees F (6.6 C)
 

Bat 1= 53 degrees F( 11.6 C)

Bat 2= 53 degrees F (11.6 C)

I’m not in the mood to rip into my wheels and place temperature data logger probes inside so I have the KS 16X acclimating outside right now to see how accurate it’s battery temperature sensors are. 

[Aneta]

3 hours ago, Rehab1 said:

Totally agree. I never leave my wheels outside.....except for this test. 

I left the Z10 outside this afternoon for 5 hours so both the temperature of the data logger and the wheel would acclimate. I need accurate quantifiable data of both both to test the thermal pad effectiveness. 

Unfortunately both of the Z10’s battery temperature sensors are off by over 9 degrees F.  The data logger is running at 44 degrees F ( 6.6 C) and the Z’s batteries are at 53 degrees F (11.6 C) . 

 Temperature Data Logger = +/- 44 degrees F (6.6 C)
 

Bat 1= 53 degrees F( 11.6 C)

Bat 2= 53 degrees F (11.6 C)

I’m not in the mood to rip into my wheels and place temperature data logger probes inside so I have the KS 16X acclimating outside right now to see how accurate it’s battery temperature sensors are. 

Curious: 1) why is it that current is drawn only from one battery, aren't they paralleled? and 2) the temperatures are always equal within 0.1F, are there actually two sensors? Hard to imagine the temperatures can be so uniform within the wheel, plus there's always noise and different calibrations.

[Andy5225]

it seems like a professional job.

[Planemo]

On ‎11‎/‎11‎/‎2019 at 3:08 AM, Aneta said:

Curious: 1) why is it that current is drawn only from one battery, aren't they paralleled? and 2) the temperatures are always equal within 0.1F, are there actually two sensors? Hard to imagine the temperatures can be so uniform within the wheel, plus there's always noise and different calibrations.

1. I believe that the Z draws whatever power it wants/needs from either pack as required. I do not believe they are hard linked, as it wouldn't be possible to regen only one pack (which it does).

2. I believe there are 2 temp sensors on the Z - one in the battery (the pack as a whole - probably on the BMS) and one on the board.