STEPS motor operating temperature range (low side)?

Ken S

Member
Shimano does not list a motor operating temperature, they only publish a battery operating temperature.
The later is down to -10C which is not very useful if the motor operating temperature is only -5C. Bosch's does publish this specification, it's -5C for two motor models I checked.

Has anyone asked and received a motor operating temperature?
It sure would have been good to know what the low temperature cut off is the symptom(s), and why the "disengagement">


My motor went into a freewheel mode when I attempted to commute the other day when it was down to -5C. Symptom: the crank would spin without engaging the chain ring. When I warmed up the motor housing with a hair dryer for a few minutes, it then engage, but after 10 minutes of riding it disengage again, -time for a taxi and a few choice words. It has been fine at -1 to -2.
 

McCorby

Well-Known Member
What series motor do you have?

These are the specs from the E8000 series manual. I believe they are for both the motor and battery.

D955E350-C500-49B6-A75F-938D020517A5.png
 

Ken S

Member
Shimano does not list a motor operating temperature, they only publish a battery operating temperature.
The later is down to -10C which is not very useful if the motor operating temperature is only -5C. Bosch's does publish this specification, it's -5C for two motor models I checked.

Has anyone asked and received a motor operating temperature?
It sure would have been good to know what the low temperature cut off is the symptom(s), and why the "disengagement">


My motor went into a freewheel mode when I attempted to commute the other day when it was down to -5C. Symptom: the crank would spin without engaging the chain ring. When I warmed up the motor housing with a hair dryer for a few minutes, it then engage, but after 10 minutes of riding it disengage again, -time for a taxi and a few choice words. It has been fine at -1 to -2.
What series motor do you have?

These are the specs from the E8000 series manual. I believe they are for both the motor and battery.

View attachment 75395
Thanks, I have seen this, but I'm not convinced, based on my issue that this is the drive unit's operating temperature range. If it is then it mine is not working anywhere close to the spec as it was well above -10.

The way it is worded and every other reference to temperature and STEPS that I have seen, it looks like the battery only temperature range.

I've got the E8000 motor.

No code was produced during the time of the issue.
Bosch has error codes for both battery and motor temperature and show in the specs "Drive Train".

They all use the same or similar cells in the battery along with the rest of the industry, so I suspect the limiting factor is not the battery but the motor. I hope to get something back from Shimano via my distributor. Access to Shimano is .... limited.

Will post results if and when I get them.

Here's Bosch specs:
1609276170380.png
 

McCorby

Well-Known Member
I have to disagree. I believe the discharge operating temperature is for both the motor and battery. Why would they list two storage temperatures, with one being specifically for the battery only? With that said, unless specifically noted, I’m pretty confident the temperature specs are for both.

Furthermore, the table also lists the drive unit type, motor type, and rated drive unit power. These are not battery specific.
 

Ken S

Member
I will post what I get back from Shimano when I get it.

I'm not a believer unless I have clear information and or have test results which back up the numbers.

Until I do, if it's below -4 I'll drive rather than ride.:confused:
 

McCorby

Well-Known Member
Sounds good. Please let us know what you learn.
It does appear that you had an issue related to temperature. Maybe the grease in the one way clutch got a little too viscous due to the low temps, causing it not to engage properly??? I could see how this might result in no error code.
 

Ken S

Member
Affirmative on posting, as well as your suggested cause. Would like to avoid an overhaul but willing if required, and if "available" just hit 21,000 kms ...

Another month or two and temperatures will not be a problem anyway on the wet coast, but would like to know either way..
 

Ken S

Member
Response from Shimano is, wait for it, ...............

"Unfortunately Shimano does not (or has not) published the operating temperature ranges for its drive units, only for batteries."

Ouch.
Not what I hoped for but an answer all the same. Forewarned is forearmed.

I'm putting a small 20 Watt outdoor warming pad on the motor when the temperature dips below 0 C, that will keep me going but sure won't help those in colder regions.
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
I'm putting a small 20 Watt outdoor warming pad on the motor when the temperature dips below 0 C
Don't. The motor warms up during the ride because it has certain efficiency, say 85%. 15% is lost as heat. If, for instance, the motor draws 200 W from the battery, 30 W has to dissipate inside the motor. I ride my mid-drives in ambient temperatures close to 0 C now. Depending on the assistance level and the ride duration, the motor of my Vado had from +11 to +50 C (bike software can measure the battery and the motor temperature). Besides, the battery also warms up although not that much as the motor.
 

Ken S

Member
Thanks for the feedback, well understood, but, you missed the main point. The motor doesn't work when it has been sitting overnight when the temp is down to -5, so it can't, won't warm it up.

Even when I did warm the motor up enough to get it to engage, -used a hair dryer on the housing for a few minutes, it stopped again after 15 minutes of riding, so heating generated by use is not keeping it warm enough when ambient is this low.
It's been fine at temperatures above this.

Shimano does need to address operational specifications of the motor and (helpful ) symptoms when the temperature is out of this operational range.
IMHO
 

Prairie Dog

Well-Known Member
Region
Canada
City
Red Deer
I don't think the low temp has been ever any issue. @Prairie Dog: You've been riding at -14C?
Yes, but that was me chugging along on my acoustic ride last night. I'll likely be riding it for at least the next three months before the Creo can finally be brought out of winter storage. :(
Currently on the lookout for a decent e-mtb.
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
There Is Nothing To Worry About At Low Temperatures (Battery and Motor Temp)

Temperature Chart.jpg

With ambient -1°C, the motor temperature never got below 9°C (maximum of 34°C), and the battery temperature never went below 7°C (maximum 18°C). Data by BLEvo for Specialized Turbo e-bikes.
 

Ken S

Member
Just in from Shimano:
They have stated "that the drive unit should able to function within the temperature range of -10C°~50C°"

I may not be able to duplicate the issue this winter as it seems to be a 1 out of 3 cycle this year with no real cold snap out here, but good to know the specifications all same.
 

antboy

Well-Known Member
I know this is a couple of weeks old, but I've taken my E6100 motor out on a couple of -5C days - just a couple :) - and it's performed just fine.

That being said, that's not from a cold start, as it's stored at room temp, and the longest it was stopped outside was about 15 minutes, so it never had a chance to get down to ambient temperature.