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[electricdominic]

Try putting your hand 12" above the asphalt - usually 150 degrees F is enough to burn you.

So sorry, but I am not going to waste ten hours of my life getting a sunburn and scorching my hand by placing it 12" off the ground for ten hours straight to attempt to prove your point.  Why don't you drop by in a month and we can video your attempt to hold your hand there for ten hours

[protomech]

No need to get snippy Even though the ground may be 170 degrees (ouch!), air acts as an insulator and you won't see those temperatures at the battery box (or, say, at your hand 12" off the ground).

I think the cycle analyst + analogger combination can be rigged to accept analog inputs. Might be interesting to hook up a thermistor to the inside of the battery box.. that or getting access to Zero's logs - if they're even recorded when the bike is "off" - are really the only ways to know how hot the battery box interior is.

[electricdominic]

No need to get snippy

nope not snippy, just a realist.

[protomech]

Sorry to drag up an old-ish topic, but here's an update.

I brought an IR temperature sensor to work today. Left work at 6 pm, temperature outside was 84 degrees (F) per weather.com.

The concrete pad (in direct sunlight) that I was parked on read 110-114 degrees (+30 over ambient).
The battery enclosure facing the sun read 106-110 degrees (+26 over ambient)
The battery enclosure shaded from the sun (bike was parked with its side to the sun) read 100-102 degrees (+18 over ambient)
The tires read 120-124 (!) degrees (+40 over ambient)
The motor housing read 101 degrees (+17 over ambient)

After 20 minutes of 35-55 mph riding, the pack read 88 degrees, the motor read 90 degrees.

After 20 minutes more of 45-55 mph riding, the pack read 81 degrees, the motor read 81 degrees. (also the outside temp had dropped to 81)

Peak enclosure temp in the sun was 26 degrees above ambient. I'm assuming the exterior skin of the enclosure is higher than the internal battery temperature - with a maximum battery temperature of 160 degrees, I'm not going to worry about battery temperatures until I see peak ambient temperatures above 120-125.

I'll repeat the readings when we get 100 degree days, which is about as hot as Huntsville gets.

[protomech]

Okay, more data. Data is an anathema to fear and hand-wringing.

Tested temperatures at 3:30 PM today. It was overcast in the morning, but the clouds lifted in the early afternoon. It's sunny now but not terribly warm. Weather.com says 79F / 26C.

My bike was parked on asphalt. The sun at the time of measuring was somewhat above and nearly behind the bike, so sunlight was hitting one side of the battery enclosure at a very oblique angle and the other side of the enclosure was in shade.

Asphalt was 103F.
The seat was 110-115F. Yes, it felt warm : )
The battery pack enclosure in shade was 88F (+9F over ambient).
The battery pack in sunlight was 96F (+17F over ambient).
Tires in the sunlight were 126-130F.
The swingarm in the sunlight was 100F.

Here's the bike's temperature sensor readings:
Pack0 29C
Pack1 27C
Pack2 28C
Pack3 28C
Pack4 29C
Pack5 28C

BMS0 29C
BMS1 30C
BMS2 29C

Interconnect0 27C
Interconnect1 28C
Interconnect2 29C
Interconnect3 28C
Interconnect4 28C
Interconnect5 29C

So, internal temperatures range from 27-30C, or 81-86F (+2 to +7F over ambient).

Supposing the temperature sensors are calibrated properly, the internal battery temperature is slightly above ambient and slightly below the coolest region of the enclosure.

[protomech]

And one more update.

We've been seeing temperatures over 100F here recently. In fact, the last few and next few days are within a couple of degrees of all-time highs for this area.

Parked the bike in an area that receives direct sunlight throughout the day, with the tail generally facing the west.

June 28:
Readings taken around 7 pm, ambient temperature 101F.
Asphalt temp was 124-128F.
Battery casing exterior was 116-118F (15-17F above ambient).

June 29:
Readings taken around 4 pm, ambient temperature 105F.
Asphalt temp was 136-148F.
Battery casing exterior was 126-130F (21-25F above ambient).

The casing exterior temperature did not increase closer to the asphalt.

Given an interior temperature 2-10F below exterior casing - at lower temperatures - and a 160F maximum temperature for the cells, I see no reason to be concerned about ambient temperatures below 120F.

[Lipo423]

This is very good information Protomech. Thanks.
We have reached 108 F in Spain in the last few days, so obviously, I would not love to "fry" my battery pack 

If the batteries we have in our packs (2012 models) are the Molicel ones the operating temperature goes from -20C to +60C (they acknowledge the fact that their bateries work better at +45C -which is good news for the subject of our concern)...especially for this summer...when the winter shows up, that will be another discussion, as I'm a bit skeptical about their hability to hold up nominal capacity at low teperatures...

[protomech]

I don't think we have hard confirmation, but the 2012 bikes use EIG C020 pouch cells. The pre-2012 bikes all used molicel cylindrical cells.

EIG rates the C020 cells at -30C to 55C (131F) storage and operation.

In the 2012 manual Zero claims the power pack should be used only in the range of -7C (20F) to 71C (160F), and the BMS will disable operation outside this range.

Why the temperature discrepancies?

It's possible on the lower end that other electronics on the bike are suitable only to 20F. It's also possible the batteries give truly abysmal performance below 20F, but I'd still like the option to use the bike in that case..

On the high end, the 55C rating appears to be a 1 month storage temperature (PDF link). Zero may have performed durability testing of the batteries above that temperature, or they may be suitable for limited duration storage above that temperature. It may be worth following up with Zero directly to see why the discrepancies exist.

131F internal temperature is still probably good for about 110F ambient. If Zero's specs are incorrect, then you would want to keep the bike shaded above that temperature.

[Lipo423]

Oh, thanks Protomech, I recall reading this comment in a different thread -I'm getting older 
I would agree with the components assumption (when I was studying electronics we always talked about "military-grade" components -or "rough terrain" as we called them)...I would really question Zero going that far for the electronic control system. The other reason -Assuming they use military-grade electronic components- is to preserve battery life at low temperatures...I have seen very few cells being able to hold up a reasonable charge level below 0 celsius, who knows...

They could have made an agreement with the manufacturer to get special cells with "tuned" chemistry -this can be done for certain applications (military, and NASA get in the game) 

I would also agree that we should be able to ride the bikes with 100% range at those temperatures, but unfortunately I do not see it practically today.

Below, you may see a general graph/chart for Lithium batteries operating temperature

[dkw12002]

I try to avoid the summer sun here, but I have been out in 100 degree sunny weather. I figure the inside of my garage gets even a little hotter, but so far my 2011 Zero S runs fine and charges fine. I don't ride any other bikes in the hot sunny part of the day in summer either cause it's even harder on me. I'm stuck with riding from 6-11am and 7-9 pm for the next 2 months at least. We've already had a couple of 104 degree days.

[protomech]

Zero has posted some guidance on hot weather operation. Somewhat apropos as we'll be entering the hot weather season shortly.

http://www.zeromotorcycles.com/owner-resources/Guidelines-for-Hot-and-Cold%20Weather-Operation-SV-ZMC-012-050.pdf

Hot weather operation of the motorcycle should not result in any noticeable performance changes. However, the BMS will not allow motorcycle operation and its associated battery discharge above 140F/60C, as measured at the battery.

Note that in hot temperatures (greater than 87F/31C for 2011-2012 Model Year) (greater than 110F/43C for 2013 Model Year), the charger reduces its charge current to the battery, increasing charge time accordingly; the hotter the ambient temperature, the greater the effect. Above a battery temperature of 131F/55C, the BMS will no longer allow charging.

Storing the motorcycle or its battery in direct sunlight in ambient temperatures above 105F/41C may result in accelerated permanent decay of battery performance, and hence it is not recommended.

Those of you in hot climes should heed the above advice.

[dahlheim]

i have been leaving the bike unplugged for an hour or two after parking before charging because the manual entry about not charging while the battery is hot has had me a bit paranoid.  what i would really love is the ability to know the below temperatures.  how did you obtain those sensor readings, please?

Okay, more data. Data is an anathema to fear and hand-wringing.


Here's the bike's temperature sensor readings:
Pack0 29C
Pack1 27C
Pack2 28C
Pack3 28C
Pack4 29C
Pack5 28C

BMS0 29C
BMS1 30C
BMS2 29C

Interconnect0 27C
Interconnect1 28C
Interconnect2 29C
Interconnect3 28C
Interconnect4 28C
Interconnect5 29C

So, internal temperatures range from 27-30C, or 81-86F (+2 to +7F over ambient).

Supposing the temperature sensors are calibrated properly, the internal battery temperature is slightly above ambient and slightly below the coolest region of the enclosure.

[protomech]

The temperature sensors are logged by the BMS board. If you have a special Zero cable (which I had for a brief time) then you can access the BMS and retrieve its current readings.