Bosch motor turns off in cold

[xMarcus]

Riding in the NYC winter in the low to mid thirties I have observed that my Bosch 2018 CX motor will sometimes not turn on in the cold weather or will turn off when riding.

Storing and charging the battery indoors definitely helps but it doesn't prevent the issue. Same for the use of neoprene covers.

Does anyone have any suggestions?

 

[rich c]

What display do you have? I'd check how clean the battery contacts are, plus the display connections at the base if you have the Intuvia.

 

[xMarcus]

Display is Purion. How do you clean the battery contacts?

 

[Browneye]

The lower temps may cause enough voltage dropout to cause a shut down. You can't really know unless you put a meter on it. Still under warranty?

Otherwise, it may be something connection related - would definitely clean and apply a little dialectric grease to all your connections. They could simply be losing contact. On my Giant, if it doesn't sense the speed sensor it shuts the whole thing down.

 

[rich c]

The lower temps may cause enough voltage dropout to cause a shut down. You can't really know unless you put a meter on it. Still under warranty?

Otherwise, it may be something connection related - would definitely clean and apply a little dialectric grease to all your connections. They cold simply be losing contact. On my Giant, if it doesn't sense the speed sensor it shuts the whole thing down.

It's been my experience that with no throttle, Bosch doesn't have the dramatic battery sag issues that many systems do.

 

[rich c]

Display is Purion. How do you clean the battery contacts?

An extreme case, but some info just the same.

Bosch battery terminal corrosion

A 3 year old Haibike AllMtn Pro with about 19000km on the clock was giving occasional battery problems. [error code 530 and occasionally loosing power] One on the problems appears to have been the state of the frame battery connection terminals. The +ve terminal appears to have lost its...

www.pedelecs.co.uk

What should I do if water runs into the battery mount?
Sterzl: The mount is designed in such a way that water can drain off and the contacts can dry. To ensure that this happens, the mount and plug area should be kept clean. The contacts are provided with a coating which protects the surface against corrosion and wear. Terminal greases or technical vaseline may also be used if necessary.

Care of eBikes

www.bosch-ebike.com

 

[tomjasz]

ALL eBikes benefit from treating ALL electrical connections with Boeshield or ACF50. For controlling corrosion AND repelling water!

 

[Browneye]

It's been my experience that with no throttle, Bosch doesn't have the dramatic battery sag issues that many systems do.

You really have no way of knowing WHAT the voltage levels are doing on his bike, throttle or no. For all we know there are bad cells in the pack, and with the cold temps it's dipping down too low and shutting down.

It may or may not have anything to do with tempurature, could be component connections, component failure, battery pack issues, any number of things. It could be as easy as simply turning the magnet on the spoke for the speed sensor.

 

[Deleted member 4210]

Cold temps have this side effect of exposing potential electrical issues, and just like a car battery doesn't always present how weak it may be during more normal temps, ebikes and their lithium batteries can do the same, and expose issues you didn't know existed.


Current flow gets affected, resistance increases, batteries don't function as well or as long, and generally it's not very obvious as to the cause.

Your best bet is to get with a Bosch Certified shop, or Bosch directly so they can give you a list of possible checks, and trouble shooting. Some Bosch shops can extract battery information as one check. There is often no one single answer for the symptom you describe. I have seen similar symptoms/issues occur with controllers in cold weather that acted fine throughout a summer season. In the case of the Bosch the controller unfortunately is built into the motor (as is the case on most mid drives) so it's a bit more work to get at it than on typical hub drives, where they are mounted externally.

It might be display contacts as Rich mentions, but there are all sorts of other possibilities.

 

[rich c]

You really have no way of knowing WHAT the voltage levels are doing on his bike, throttle or no. For all we know there are bad cells in the pack, and with the cold temps it's dipping down too low and shutting down.

It may or may not have anything to do with tempurature, could be component connections, component failure, battery pack issues, any number of things. It could be as easy as simply turning the magnet on the spoke for the speed sensor.

Do you ride Bosch powered eBikes? Or have actual experience with there feedback and error codes?

 

[Browneye]

Do you ride Bosch powered eBikes? Or have actual experience with there feedback and error codes?

I don't need said experience to comment. These are not brand-specific issues. Carry on.

 

[tomjasz]

I don't need said experience to comment.

Of course not. But if you had experience with Bosch systems your advice might have been useful. As it is you're assuming the Bosch management, BMS, is similar to your budget kit battery. I think Rich is trying to get more information specific to the OP's system. A number of the issues you bring up just aren't likely with Bosch packs.

 

[tomjasz]

Bosch-eBike-Battery-Guide-MY2020-EN.pdf

Winter use – During winter use (particularly below 0 °C) we recom- mend charging and storing the bat- tery at room temperature before in- serting the battery in the eBike im- mediately before riding it. For longer journeys in the cold, it is advisable to use thermal protective covers.

 

[Browneye]

Of course not. But if you had experience with Bosch systems your advice might have been useful. As it is you're assuming the Bosch management, BMS, is similar to your budget kit battery. I think Rich is trying to get more information specific to the OP's system. A number of the issues you bring up just aren't likely with Bosch packs.

I completely understand. But that's not what he commented on, and his very first recommendation was battery contacts. I can't speak specifically on Bosch, but in many cases any failed contacts in the system has the potential to cause a system shut down. Even you confirmed this, and Rich even directly related a recommendation for cleaning and greasing battery contacts.

I guess we'll see what the resolution is. Will be interesting when it comes back that there are bad cells in the pack and it's dipping low enough to shut the system down. I can't wait to be wrong. My hope is it's more simple than that. For wet and cold my bet is on a bad sensor connection somewhere in it.

I'll bow out and let you guys troubleshoot it for him. If it were me I would drop it to my dealer/shop that works on that brand.

My Giant doesn't have a 'budget kit battery' bms. Or maybe it does. [shrug] I do know if it's sensors are not connected the system shuts down. BTDT.

Hope it gets worked out.

 

[elliot friedman]

x

Riding in the NYC winter in the low to mid thirties I have observed that my Bosch 2018 CX motor will sometimes not turn on in the cold weather or will turn off when riding.

Storing and charging the battery indoors definitely helps but it doesn't prevent the issue. Same for the use of neoprene covers.

Does anyone have any suggestions?

Afternoon Xmarus,

As a fellow New Yorker, I've had intermittent shut downs for at least a year and a half no matter what the outside temps are. I've had the intuvia, the intuvia mount, and the battery to motor harness replaced to no avail. Lastly my LBS upgraded the firmware a little over a month ago with no problems thus far, though, I'm not riding as much. He told me if it happens again Bosch will replace the motor itself.
Bring yours to where you purchased and ask them to do a diagnostic report. Hopefully you bought yours here in the city. It's a very frustrating situation especially with no error messages. I wouldn't count on it having to do with NYC weather.

Best of luck.................elliot

Several threads on the topic you could check out as well.