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[gadgetgirl]

Based on some forum searches and basic battery knowledge, I know batteries don't always perform well in the cold. However, my SR/F died 3 times on my commute home tonight. The bike was sitting at the curb in downtown Chicago in the upper teens/20°F range all today, with 94% SoC. When I turned the bike on, it gave me the message that it was warming the 12V battery, which I've seen before and expected. However, stopped at a red light, the green circle arrow light shut off and the bike wouldn't move. Cycling it off/on, it showed the warming 12V battery message again, but also showed a message about the 12V being ineligible, and shut the bike off completely (dash powered off, headlights off, key still in the on position). I switched the key off, gave it a couple minutes, and turned it on. After another message about warming the 12V battery, the bike would move again.

This happened a few more times, only stopped at traffic lights. Is this just a design flaw on the bikes, or something specifically borked with my 12V battery? I'll ask the dealer soon too, but I was curious if others are seeing this. I wish I had an option to park the bike in a warm area during the day, but that's not going to be easy. It's going to seriously suck if I just can't ride when it's cold out.

[DonTom]

Based on some forum searches and basic battery knowledge, I know batteries don't always perform well in the cold. However, my SR/F died 3 times on my commute home tonight. The bike was sitting at the curb in downtown Chicago in the upper teens/20°F range all today, with 94% SoC. When I turned the bike on, it gave me the message that it was warming the 12V battery, which I've seen before and expected. However, stopped at a red light, the green circle arrow light shut off and the bike wouldn't move. Cycling it off/on, it showed the warming 12V battery message again, but also showed a message about the 12V being ineligible, and shut the bike off completely (dash powered off, headlights off, key still in the on position). I switched the key off, gave it a couple minutes, and turned it on. After another message about warming the 12V battery, the bike would move again.

This happened a few more times, only stopped at traffic lights. Is this just a design flaw on the bikes, or something specifically borked with my 12V battery? I'll ask the dealer soon too, but I was curious if others are seeing this. I wish I had an option to park the bike in a warm area during the day, but that's not going to be easy. It's going to seriously suck if I just can't ride when it's cold out.

I am no expert on the SR/F, but I think 20F is probably making the BMS turn the battery off. Check to see if there is a spec on how cold you can ride a Zero SR/F. You are probably below that operating range. When it is that cold, a battery motorcycle is a very poor choice.

Edit:

I just found this info here.  Looks like it should run down to -4F. but will not be able to charge that low. You have to be above +32F to charge. But 20F could be in a range where things start to get flaky for even running. I do not know how accurate that operation spec is. but IMO, 20F is just way too cold to be using  an electric motorcycle.

Also see the info. on cold weather riding in the Unofficial Zero Manual.

"The manual recommends not running the bike if the battery temperature is below 23F/-5C, and then if you do, immediately put the bike on a charger once its temperature is raised to 32F/0C. The BMS will open the contactor at -22F/-30C per Farasis' recommendations."

However, note that this info. is not for the Zero SR/F, but is probably still applies, as it is still the 14.4 KWH battery.

-Don-  Reno, NV

[BrianTRice@gmail.com]

You can wrap the battery in 1/8" neoprene sheeting to keep the cold air and possible moisture off of the case, which I typically suggest to reduce range and performance loss at low temperatures.

I've only tried making them for my DS+DSR, so the SRF will require new techniques to fasten it properly, but it is effective and pretty safe by not being too thick.

I don't know about protecting the 12V battery, though.

[gadgetgirl]

Thanks guys. I see in the manual where is says it's not recommended to ride if the pack is below 23°F. I expected loss of range, but not total power failure. To your point Brian, I'm not sure how I would wrap the 12V, but neoprene for the main pack seems doable. It would be nice if you could opt for the pack to sacrifice SoC to keep itself near the lower useable temp. Yes, it would be a countdown for how long it could maintain it, but letting itself cool to unusable seems worse.

I guess it's time to put my bike to bed for the winter. I'm also seeing they recommend keeping it plugged in over the winter if the storage area gets cold, so I intend on keeping it plugged in.

I am no expert on the SR/F, but I think 20F is probably making the BMS turn the battery off. Check to see if there is a spec on how cold you can ride a Zero SR/F. You are probably below that operating range. When it is that cold, a battery motorcycle is a very poor choice.

Edit:

I just found this info here.  Looks like it should run down to -4F. but will not be able to charge that low. You have to be above +32F to charge. But 20F could be in a range where things start to get flaky for even running. I do not know how accurate that operation spec is. but IMO, 20F is just way too cold to be using  an electric motorcycle.

Also see the info. on cold weather riding in the Unofficial Zero Manual.

"The manual recommends not running the bike if the battery temperature is below 23F/-5C, and then if you do, immediately put the bike on a charger once its temperature is raised to 32F/0C. The BMS will open the contactor at -22F/-30C per Farasis' recommendations."

However, not that this info. is not for the Zero SR/F, but is probably still applies, as it is still the 14.4 KWH battery.

-Don-  Reno, NV

I hear you, but I don't think it's unreasonable to expect the bike to regulate its temp. It has a 12V pack heating element, and came pre-installed with the heated grips... 23°F is their lower spec, but I would have preferred a bit lower. It's only a poor choice if the engineering doesn't handle the conditions... but it could have. At least I learned its limits today.

[Curt]

I hear you, but I don't think it's unreasonable to expect the bike to regulate its temp. It has a 12V pack heating element, and came pre-installed with the heated grips... 23°F is their lower spec, but I would have preferred a bit lower. It's only a poor choice if the engineering doesn't handle the conditions... but it could have. At least I learned its limits today.

I had my FX on the freeway the other day at 38F with heated vest and grips, and I almost died. You are hardcore.

[JaimeC]

The more I read about the quirks of the SR/F, the happier I am that I didn't trade in my S...

[SBK74]

Manual:

The 12 volt battery is equipped with a heater to warm it when
current (or recent) temperatures have been recorded below 41°F
(5°C).

Note: During this warming, the motorcycle will be temporarily
disabled for 1-15 minutes until the power pack’s temperature is
determined to be above 32°F (0°C)

[Tom_Ruyter]

Also, don't forget about wind chill.

For those of us that used to suffer carb-icing on our older ICE bikes, it's one thing to be warm at standstill, but moving through cold air reduces the temps even further. Might have been 20F at rest, but certainly moving through the air would have made the bike colder.

[DonTom]

Also, don't forget about wind chill.

I don't think wind chill is a factor to an item that is not  already warmer than the wind.

It is a factor to us humans because wind blows off our body heat. But if an item is at the same temperature as the surrounding air, then air moving by it at the same temp should have no effect.

Note that some weather reports show both, the real temp and the reel-feel temp which can be quite a bit different. Objects do NOT "feel" so that doesn't not apply to objects. The temp is the actual temp always to objects that have no heat to blow off.

However, there could be a little heat to blow of some areas of an electric motorcycle, such as a battery or motor that is getting warmer from it's own electrical heat.

-Don-  Reno, NV

[Crissa]

Wind chill also affects static objects.

Otherwise fans couldn't cool electronics.

-Crissa

[DonTom]

Wind chill also affects static objects.

Otherwise fans couldn't cool electronics.

-Crissa

That's because they have heat to blow off, just like I said.  But what if the item is already at the same temperature as the air around it? How is that wind going to to make  anything cooler when the wind is at the same temperature?

BTW, wind can also warm things, including us.  You would know this on a windy night in the summer in Death Valley. That is because the wind is a higher temperature than our body temp. Feels like a blast furnace to get hit by that wind. Then no wind is cooler than having wind.

-Don-  Reno, NV

[gadgetgirl]

I had my FX on the freeway the other day at 38F with heated vest and grips, and I almost died. You are hardcore.

Haha. Well, snow pant overalls make a big difference, and my commute is mostly local roads with a small segment of highway. Dressing the same as skiing makes it pretty comfortable for me.


Regarding the 12V battery and windchill, isn't that battery under the seat? I would think it's shielded from airflow, unlike the main pack. I'm not sure when the season will be over for me this year. Chicago has very screwy winter weather this year. It's a high of 48°F today, and supposed to be a low of -2°F next Thursday. I need to move somewhere warmer.

[Crissa]

That's because they have heat to blow off...

...Which is wind chill.  Like all effects, it is a curve, but it only slows down, it doesn't stop.  In fact, dragging away excited atoms works all the way down to absolute zero.  https://en.wikipedia.org/wiki/Laser_cooling

-Crissa

[Curt]

But what if the item is already at the same temperature as the air around it? How is that wind going to to make  anything cooler when the wind is at the same temperature?

This is correct. The battery can't get cooler than the wind; if it was, the wind would warm it up. Heat always flows from warmer to cooler so that the temperature difference shrinks asymptotically towards zero.

The rate of heat transfer depends on the temperature difference. Wind (coolant circulation) helps maximize the difference by moving already-warmed (or cooled) air out of the way, and so it keeps the rate of heat transfer near maximum.

A wind chill calculation looks the rate of heat transfer given the wind and temperature, and finds at what temperature the rate of heat transfer would be the same without wind. That is a fake temperature that will never be reached, as the actual temperature can't go below ambient.

[DonTom]

But what if the item is already at the same temperature as the air around it? How is that wind going to to make  anything cooler when the wind is at the same temperature?

This is correct. The battery can't get cooler than the wind; if it was, the wind would warm it up. Heat always flows from warmer to cooler so that the temperature difference shrinks asymptotically towards zero.

The rate of heat transfer depends on the temperature difference. Wind (coolant circulation) helps maximize the difference by moving already-warmed (or cooled) air out of the way, and so it keeps the rate of heat transfer near maximum.

A wind chill calculation looks the rate of heat transfer given the wind and temperature, and finds at what temperature the rate of heat transfer would be the same without wind. That is a fake temperature that will never be reached, as the actual temperature can't go below ambient.

Yep. Heat is energy. Even when we're freezing cold  from a very cold wind   Cold is not energy, but is the name we use for a lack of the energy called heat.

So if the battery pack is at 30F. and the temp is 30F.  and the wind is 30F.  there is NO effect of the wind on the battery. It stays at 30F.  And even 30F  is heat energy, which is quite cold! If it's a warmer wind coming from a place where it is warmer, saybe 32F, then the freezing cold wind could heat up the 30F.  battery a degree or two.

-Don- Reno, NV