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[trikester]

I am bummed out! Because I'm living at the beach, in Southern California, I can't get into this competition. 

Trikester

[BSDThw]

Also there are safety measures in place to not allow charging the batteries below freezing, but if you know the temperature is that low outside, don't even try as some very bad things could happen.  Not really until a couple degrees below freezing, and I think the safety cutoff is set right at freezing, so a little buffer. Best to push the bike in a garage or lobby or anywhere to warm it up first.

Believe the owner's manual states that the BMS will disable charging below 20F.

You make me scared I tend to connect my bike always to the grid (all winter long) and my garage is not much different to the outside.

I never wasted a thought it could be dangerous. Do I really need to disconnect it at low temperature?

I am a bit worried now.

 

[kcoplan]

Believe the owner's manual states that the BMS will disable charging below 20F

That's what my manual says -- at p. 4-8

Action
: if the BMS senses that the power pack is too hot, above 71C (160 F) or too cold, below -7C (20F), it sends a signal to disable the motor controller and the motorcycle will not run until the temperature returns to an acceptable level.  The charger will also be disabled in this condition.

[protomech]

From the 2012 owner's manual:

It is required that you leave the motorcycle on the charger if you expect it to sit in storage or unused for over 7 days. The power pack must be charged within 24 hours if fully discharged, and charged within 60 days if stored fully charged. Zero recommends you plug in your Zero motorcycle after 7 days, even if fully charged. Please leave your Zero motorcycle plugged in whenever possible.

High or Low Temperature
Action: If the BMS senses that the power pack is too hot, above 71°C (160°F), or too cold, below -7°C (20°F), it sends a signal to disable the motor controller and the motorcycle will not run until the temperature returns to an acceptable level. The charger will also be disabled in this condition.

Self discharge + BMS battery drain should be very low. 7.9 kWh / 60 days = 5W discharge .. pretty small.

I don't know at what temperature the electrolyte in the battery would freeze - might be good to contact Zero if it's dropping much below.

Charging it for 1 hour per week should be enough to keep it more or less at a stationary state of charge. If you get one warm day per week, then you could probably sit the bike out in the sun to warm up and then charge.

Alternatively, you could bring it inside to charge periodically, or just store it inside period. That's probably safest for the bike batteries if it drops well below 20F outside.. though perhaps not safest for your domestic relationships : )

[protomech]

Rode in to work, temp around 40. 12 miles @ 40-60 mph.
Left in the evening, rode to a friend's house, temp around 35. 16 miles @ 40-50 mph.
Just lost the fifth bar when I arrived. 6 bars remaining, figured I had about 35 miles left in the pack. No problem, 20 miles to go home.. no need to charge (even though we were going to watch about 4 hours of Rome, heh).
Left around 11, temp around 30. Switched on the headlight, finished gearing up, noticed the sixth bar had disappeared. Sometimes I see this after the temperature drops significantly when the bike has been sitting. No problem.. until a mile later the seventh bar disappears, then the eighth, then all bars disappear and the fuel gauge starts to flash.

I debated whether to pull over at a restaurant to charge. I had just made this trip last week in slightly higher temperatures (40-45 degrees) using about 70% of the pack, so I knew the battery wasn't out of charge.. just figured the voltage was low enough that the energy gauge gave up on giving a range estimate. As long as the battery stayed above the lower voltage cutoff, the bike would keep rolling..

Which it did. For all 20 miles.. but I kept to 35 mph as much as possible.

Rather nerve-wracking.. but take it as another data point.

I'm going to do some test riding this weekend when it's warmer, see if the energy gauge exhibits similar irregularities then.

[Richard230]

After what Terry rode through to get to the Bay Area, I thought that he would have seen some degradation in his battery pack or performance. But when he rode up at the Zero factory, he said that his battery pack was working just as well as it did when new, even though he has more miles and his bike has likely been abused it more than anyone else has done to their Zero.  I would say that is a pretty good testimonial for Zero's battery pack - no matter what the LCD "fuel" gauge says.   

[protomech]

I wonder if he got his weak cell replaced at Zero HQ?

[kingcharles]

If you ride a lot the battery will keep some heat due to the discharge and charge cycles. This will help the battery to keep its capacity in cold weather.
I ride twice a day to empty tank and have little degradation of range. But after its parked for a few days it takes some rides to "warm up" again.
My expirience is with another chemistry though (NiMh) so maybe it applies less to Li

[ColoPaul]

Mildly interesting observation:

It's been very cold the last 8 days here, average daily temperatures of around 12F.  I haven't been riding at all.
The ol' zero has been sitting in the (relatively warm) garage; but I noticed yesterday I was getting a blink code on the BMS:
1 red, and 1 green.  A quick glance at the manual yielded:  "Too Hot.  Let the power pack cool down".    The thermometer in the garage was at 33F; the battery box was ice cold.
I turned on the garage heater, and let the temp come up to 50F.  The blink code was gone and now it was charging.
Went back to the manual, and saw the "Too Hot" blink code is under the heading "Temperature Disable", and that there is no "Too Cold" blink code, so too cold and too hot must share the same code.
I know the garage temp was above 32F cause there was some water in there that wasn't frozen.
Apparently, for my bike, around 32F is the cold charge limit;  although the manual references 20F.

[trikester]

I feel for you guys in the cold temps. I went mountain biking today (see photo) in the Anza-Borrego Desert State park and tomorrow I'll take the 2012 DS out for a dirt ride. The temp today was 60 degrees and no wind. It's supposed to be warmer tomorrow.

Trikester

[dahlheim]

I feel for you guys in the cold temps. I went mountain biking today (see photo) in the Anza-Borrego Desert State park and tomorrow I'll take the 2012 DS out for a dirt ride. The temp today was 60 degrees and no wind. It's supposed to be warmer tomorrow.

Trikester

i'll send you a picture from the mountains in August where it'll be in the 70's-80's, then you send me a pic of your thermometer...?  for now, i'm going skiing

[trikester]

Ah, but I also have a mountain cabin located at 7,000 feet. About the same August temps as you said. There are good Forest Service fire-roads to ride up there in the summer. In the winter, if I skied, I could ski up there, but since I don't ski I'd rather be down in the desert.

Trikester

[kcoplan]

Just got back from a 32 mile round trip to a meeting with a client.  Left from a 45 degree garage, 24 degrees outside.  Parked the bike outside for three hours ( temperature around 30 degrees)  then rode back.

Really did not notice much effect of the cold on range or the battery indicators.  I used three bars (had eight left) when I reached my destination.  Still had eight bars left when I turned the bike on three hours later.  Used three bars to get home, leaving five bars on the bike.

The trip was half freeway and half back roads, average speed around 40 mph, top speed not more than 55 or 60 (didn't want to push the range).

My bike is a S ZF6, so using six bars to go 32 miles in a mix of freeway and suburban driving is better than the advertised range of 45 miles for mixed commuting.

One thought - another factor that would decrease range in cold weather would be the increase density of cold air.  This has to increase wind resistance at high speeds.

[NoiseBoy]

I found some info about it on cycling and increasing the air temp by 5C in the velodrome at the London olympics reduced times by 1.4s in the 4km time trial (about 4m 20s) A difference of roughly 0.6%.   So I suspect that doing up the zip higher on your jacket because of the cold would have more aerodynamic effect on range than the cold air itself.

[benswing]

I know it's not the coldest, but I took a ride in 28 degree weather last week.  Was late for the meeting so I was hitting high speeds on the highway, while ducking under my windscreen for a little cover.  Between the cold and the merciless use of the throttle, projected range was about 60mi, but that wasn't a concern since my ride was about 40 miles total.