Warm up...

[The Fat Unicyclist]

Okay everyone here is a question for you all... When it's cold, is there any benefit to warming my wheel before i push it hard? 

I suppose this is a battery question, as I don't believe the motor is affected... So when it is cold (ie. <5°C / <40°F) is it better for my batteries to start riding gently (allowing lower current to "warm" them) before leaning into it a bit more?

Or is it all rubbish and I should just go for broke...

[Keith]

2 hours ago, The Fat Unicyclist said:

When it's cold, is there any benefit to earning my wheel before i push it hard? 

Yes you would definitely want to earn it before pushing too hard ?

Low temperatures seem to have the effect of increasing the internal resistance within the cells, whilst this will in itself you would think would simply result in heating them up more quickly it does seem to degrade the cells over time. Obviously the best strategy is to start with the battery at room temperature.

@esaj and  @EUC Extreme are probably our best experts on this being that they ride in such sub-tropical paradises as Finland! I believe @EUC Extremehas arranged heating on his battery packs?

@esajhas covered this in his usual comprehensive style here:

 

[Slaughthammer]

3 hours ago, The Fat Unicyclist said:

I suppose this is a battery question, as I don't believe the motor is affected... So when it is cold (ie. <5°C / <40°F) is it better for my batteries to start riding gently (allowing lower current to "warm" them) before leaning into it a bit more?

Discharging under high load and low temperature is a good way to shorten the lifespan of your battery, an even better way is charging it when it's frozen. It's better to not let the battery cool down below 10°C before riding, and especially before charging. If you start with a warm battery in cold weather, the battery will most likely not cool down to much, as losses inside the battery produce some heat, however I'd not rely on the battery warming itself up from below 0°C. I once tried that, and got a low battery warning within about three minutes of really slow riding.

[esaj]

I haven't had the pleasure of trying winter-riding, There hasn't yet been a winter where I'd have a working wheel   But EUC Extreme mentioned to me once that without battery heating and Finnish winter (-15...-30 Celsius or such), starting from the room temperature the battery dies in about 10-15 minutes while riding (as in, not "dies" like doesn't work at all anymore, but apparently it won't give high enough voltage for the wheel to keep working). I've also read the warning not to charge batteries below 0 Celsius, IIRC, it can damage them permanently.

At least earlier, EUC Extreme's heating systems were made by some guy who usually builds them for RC-helicopters & planes for winter flying.

[Rehab1]

 Interestingly I have been researching for Lipo battery warmers for my ACM mods. Ideally I want a thin heater plate that can be placed permanently over my Lipo packs and powered by a 5v USB port like those installed on many Gotway wheels. 

 

These little heater pads I found on EBay would be ideal http://pgj.cc/3I1BBf. 

Specifications:
Material:Non-woven and carbon fiber heaters.
Size:6cm*20cm +1.5 m long USB cable
Thickness:0.5mm
Surface temperature:40-45（℃）
Voltage:5-6(V)
Power:2A 10W
Color:White

 

Given their dimensions it would probably require 2 pads for each pack.

[Carlos E Rodriguez]

I think you might want to look at the pads used to heat the seat in cars. Maybe you can get the cheap at the local auto recycler. 

@Rehab1 how you doing?