Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[DonTom]

I know this is an old thread, but I also lost significant range/power while riding in the winter on both my 2012 and my 2015 Zero bikes. After doing some research I found out that the battery chemistry that Zero uses is THE MOST sensitive to cold temperatures of all Li-ion batteries. They are also the most energy dense. This makes sense for most motorcycle riders that only ride in good weather. I ride year-round, so I notice it every year.
My '15 SR range drops from 100 mi/charge in the summer to about 80 mi/charge in the winter once the temperatures drop below 40F.

I am glad you replied  to this old thread.

Have you also noticed a big change in your charge times? While my range has been around half of last summer,  the charge time has also decreased to half,  much like as if the battery was really only half the size, with both range and charge time.

-Don- Tulare, CA (RV with Zero DS)

[oobflyer]

I am glad you replied  to this old thread.
Have you also noticed a big change in your charge times? While my range has been around half of last summer,  the charge time has also decreased to half,  much like as if the battery was really only half the size, with both range and charge time.

Actually - to be honest - I'm not sure. When I charge at home I charge with the off-board Delta-Q charger (the onboard charger was removed to make room for the DigiNow Bellypan setup). The Delta-Q charges quite slowly, so I don't keep an eye on it - I just leave it plugged in for 6 or 8 hours depending on how low the charge is.
When I charge with the DigiNow setup (6.6 kW) the fuel gauge doesn't really sync with the battery voltage - so I'll watch until the fuel gauge says 75-80%, but when I unplug the bike - the fuel gauge will jump up to 90-95% (but not always), but then it will creep back down 5-10%... I guess it's trying to analyze the actual charge(?). It's quite strange. I try to watch the voltage on the phone app for a more accurate idea of the battery charge.

Now that you ask that question I'll have to pay more attention next time I charge in the cold :-)

[Doug S]

There's no question at all that battery performance drops in the cold. I'd argue that it's a somewhat self-limiting phenomenon....if the battery is cold, internal resistance is high, which would warm the battery up fairly fast. But again, I'm never going to say that cold doesn't reduce a battery's performance, because it absolutely does, very significantly.

But don't forget the effect of cold air on wind resistance. Cold air is much more dense than warm air (ask any pilot you know about that), so your aerodynamic drag goes up quite a bit when the temperature drops, as well. You require more watts to go a mile just when your battery isn't as capable of supplying watts as efficiently.

I've often wondered how much of the reduction in performance EVs see in the cold is caused by reduced battery performance, and how much is caused by increased drag. It would be an interesting study to see someone conduct.

[Richard230]

I ride to my daughter's home on my Zero, at the same speeds, over the same distance, on the same route.  It takes about 30% more battery power to do that ride when the temperature is 40 degrees F, compared with 60 degrees F.

[DonTom]

I ride to my daughter's home on my Zero, at the same speeds, over the same distance, on the same route.  It takes about 30% more battery power to do that ride when the temperature is 40 degrees F, compared with 60 degrees F.

Do you also notice a difference in your charge times?  I don't mean on the display, as mine could say two hours to full but I am at full in around 50 minutes.

-Don- Auburn, CA (back home)

[Richard230]

I ride to my daughter's home on my Zero, at the same speeds, over the same distance, on the same route.  It takes about 30% more battery power to do that ride when the temperature is 40 degrees F, compared with 60 degrees F.

Do you also notice a difference in your charge times?  I don't mean on the display, as mine could say two hours to full but I am at full in around 50 minutes.

-Don- Auburn, CA (back home)

I recharge at her home and then at my home when I return. The charge times after a 37-mile ride remain about 3 hours, but both my daughter's garage and mine are warmer than the ambient temperature during the winter by about 20 degrees.  Thinking about it further, I wonder if the SOC display gets goofy during cold weather?    Cold temperatures also noticeably affect the display's estimate range.

[BrianTRice@gmail.com]

I have never found that while riding in the cold, that internal heat from the battery offset the cooling effects of the weather significantly.

The only way I've found to keep performance up in the winter is a combination of:
- Charging at a reasonably high rate (above 0.4C but let's say 3-6kW) just before riding.
- Securing an insulating layer around the battery pack, light but breathable, to keep cold air and moisture from impacting the casing. I recommend 3mm (1/8") of neoprene for a wide variety of conditions, because it doesn't take much to insulate and you don't want to over-insulate.

The battery has reportedly (from logs) 7 temperature sensors and an ambient temperature sensor to rely on, but the effects on SoC are probably crude at best.

Even with the battery in perfect temperature conditions, cold and wet weather will still detract from range because of the increased air density and drag. Rain/precipitation is a literal impact force on the front of the bike. But with a layer over the battery, the reduction is much less than normal.