Bosch CX shutting off randomly

[Anders]

During this morning's commute to work it happened. The bike just went dead. When I looked down at the LED remote, it was dark. I tried to turn it on again, and after a few attempts, it did power up. I went on biking, but shortly after, it happened again. Then I noticed the short "beep" it does when I turn it off. Just the same behavior as if I had pressed the on/off button. I still had 3-4 km left of my trip, and it happened 3-4 times more.
No error messages in the Flow app, no other indications of what could be wrong. I tried to pull and reinsert the cable in the LED remote, no difference in behavior.

I haven't done anything to the bike lately, so there is no reason an intenal cable should be pinched (unless it has been pinched all the time). The bike is my Haibike and the motor is the Performance Line CX smart system with LED remote, no other display. I have ridden it approx 1200km.

Any advice? How does the system behave if the battery in the LED remote is bad? Could that be the case here?

Edit: After a quick google search, I found this on the Bosch site:

This may indicate a cable connection error. Please check that all cables are properly connected and that the plugs on the control unit and the display (if present) are firmly inserted. Also check whether the cables are excessively tensioned when steering the eBike. If this is the case, it could indicate that the connection between plug and socket has been interrupted.

I guess I have to take a look behind the covers, then

 

[Mikerb]

I don't know how the battery is fixed in your bike but I would check the battery connection first since it more likely to be a connection rather than cable issue.

 

[Anders]

I don't know how the battery is fixed in your bike but I would check the battery connection first since it more likely to be a connection rather than cable issue.

Thanks!
The battery is pushed into the front downtube from below and locked by a lock at the bottom. If that lock fails, the battery will slide down and surely loose connection.
I will check when I get home (I hope I get there without too much hassle...)

 

[Stihldog]

If you’re satisfied that the wiring harness , 2032 battery, connections etc. are in good condition …check the main battery connection. On three other Bosch bikes, including mine, this was the issue.

If the battery slightly rattles or vibrates around it could momentarily loose power. Make sure you follow the battery alignment procedure and that any unnecessary movement is eliminated.

A small adjustment at the lower bulkhead solved the issue on each bike …however I also added some small cushioning to prevent any micro-vibrations.


Small felt cushioning placed in the battery compartment helped with irritating rattling noises also.

On my bike I would temporarily loose power at a specific spot and a specific vibration frequency …it was almost predictable. (Wasn’t a buried Flux-Capacitor btw). I was able to peddle through (power returned).it but it was annoying.

 

[Mikerb]

The 750 battery is a heavy beast and needs really secure fixing in the downtube. I would say the most secure is a Bosch rail system since the battery is held by sliding on runners to the rail and both the wiring connector at the top and clamp arrangement on the bottom are also attached to the rail (which is steel). Where a brand chooses not to use the Bosch rail system there needs to be alternative methods to hold it still. Note the electrical connector has 2 guide lugs to help accurately mate female battery connectors onto the connector pins.....but it is not designed to securely fix the battery. Any lateral movement of the battery will eventually cause a bad connection. Repeated removal and replacement of the battery can also damage that connection if not done carefully.
Long winded way of saying check that battery connection!!

 

[Murphius]

Dielectric grease where the battery terminals mate to the wiring harness terminals

 

[Stihldog]

Dielectric grease is a great product under the right conditions and position. I personally don’t apply it to the battery terminal and wiring harness connection. Vibration and/or incorrect fit is the main cause of power loss at the battery terminal. I worry that any moisture in this area may not be able drain out or dry properly.

I do apply a very thin layer of diaelectric grease to the small rubber ribs of wired motor connections (3 or 4). Not to the terminals…because of the mess it can cause. My main reason I use dielectric grease is to keep water out…but in certain areas it can trap water. But if it works …

 

[Murphius]

Dielectric grease is a great product under the right conditions and position. I personally don’t apply it to the battery terminal and wiring harness connection. Vibration and/or incorrect fit is the main cause of power loss at the battery terminal. I worry that any moisture in this area may not be able drain out or dry properly.

I do apply a very thin layer of diaelectric grease to the small rubber ribs of wired motor connections (3 or 4). Not to the terminals…because of the mess it can cause. My main reason I use dielectric grease is to keep water out…but in certain areas it can trap water. But if it works …

Prevents oxidation at the terminals by keeping water and oxygen from reaching them. It’s fixed the issue for a ton of people with the same issue with Bosch systems. Not preventing water from draining, the battery is a sealed system, dielectric grease keeps water from the terminals. How in the world would there be water in the battery?

 

[Stihldog]

How in the world would there be water in the battery?

Very very unlikely. Water in the battery =bad.
The water or moisture could collect at the terminals of the battery/harness. I do agree that oxidation could occur at these connections …but movement, vibration or incorrect positioning would be my main concern.

Besides, how much dielectric grease would you need to prevent any water or moisture from reaching this point? Would it never rub away? How would moisture get out? Gravity and evaporation can be our friend here.

Dialectric grease can help prevent oxidation. It can also prevent water ingress. It can also damm water or moisture and therefore prevent evaporation.

 

[theklaw]

I had a similar issue and it turned out to be the bike lock function. Hasn’t happened again since I disabled it in the flow app.

 

[Stihldog]

I had a similar issue and it turned out to be the bike lock function. Hasn’t happened again since I disabled it in the flow app.

I disabled the lock function also a few years ago. Can’t remember exactly what happened, or why it locked me out. I’m worried to use it again. It’ll remain disabled.

 

[Spiff]

Dielectric greases are a type of lubricant specifically designed for electrical applications. These greases are typically formulated from silicone and primarily serve as a non-conductive barrier between electrical components.

Non-Conductive means that if you apply it in the male and female battery-motor contacts, it will void the electric contact so motor won't work. You can apply it around to prevent moisture get inside that area, but not in the contacts.

There are conductive greases that you can apply in the battery-motor contacts and they will improve the contact and also protect it

 

[Murphius]

Dielectric greases are a type of lubricant specifically designed for electrical applications. These greases are typically formulated from silicone and primarily serve as a non-conductive barrier between electrical components.

Non-Conductive means that if you apply it in the male and female battery-motor contacts, it will void the electric contact so motor won't work. You can apply it around to prevent moisture get inside that area, but not in the contacts.

There are conductive greases that you can apply in the battery-motor contacts and they will improve the contact and also protect it

Please be sure you know what you’re talking about before responding with incorrect info. Yes it’s non-conductive but the idea is for it to form a barrier around your connection. When the terminals contact each other, they displace the grease around their connection forming a barrier around the connection, not between. The connection on the Bosch battery is not sealed with a gasket between the battery and the male terminal in the bike nor is the position perfectly static, this allows movement between the terminals paired with exposure to contaminants, leads to oxidation between the metal terminals. This is where the dielectric grease is so helpful.

Go look up dielectric grease applications in marine environments on connections that aren’t sealed well with a gasket and you’ll see this is very common.

 

[Spiff]

I am totally sure that I know what I am talking about, I greased pins of Shimano BT-E8010 battery, and after mounting it in the frame I got the E010 error, I wiped out the pins with a wet towel (wet with alcohol) and error dissappeared. So in this case, when the terminals contacted each other, they didn't displace the grease around their connection, but voided the connection.

I know this is Bosch thread, and this happenned in a Shimano, but they shouldn't be too different.

I do not know if dielectric grease works in your marine environments, but I do know it didn't work in my ebike battery.

 

[Mikerb]

dialectric grease is (as stated above) designed to prevent arcing from one terminal to another..or nearly by metal structures. It is not designed to apply to metal connectors..........nor is any other grease for that matter since it will only attract dust and dirt. Standard lithium grease can be used to guard a gainst water ingress into a plug/socket...male female type connector if applied to the outside of the connection.

That said the best plan is to keep the connector free of any water ingress and that can ( and should) be done on most bike designs with a bit of DIY
. The hardest design to achieve that effectively is the open fronted down tube, sealed only with a plastic/rubber cover located just where most mud and water is chucked up on the bike by the front wheel.

For solid downtubes there is often an opportunity for water ingress from above.....typically cable grommets in the top tube and top tube mounted controllers.............and cabling through the headset. All potential entry areas can be sealed.

The a ctual metal connections are best kept clean and the best way to do that is to occasionally use proprietry contact cleaner. That cleaner will remove oxidation and help protect connectors from oxidation.

 

[Murphius]

dialectric grease is (as stated above) designed to prevent arcing from one terminal to another..or nearly by metal structures. It is not designed to apply to metal connectors..........nor is any other grease for that matter since it will only attract dust and dirt.

I’m not going to keep at it with you guys, this will be my last response as some of you are just too bone headed to listen.

Dielectric grease is literally designed to be applied to the metal conductor, battery terminal, etc and insulate it.

Let’s use a product description to support this argument: “Typical applications include spark plug boots, distributor cap nipples, battery terminals, ignition coil connectors, and trailer electrical connectors.”

Pulled from a Loctite Dielectric grease specification: https://datasheets.tdx.henkel.com/LOCTITE-LB-8423-en_GL.pdf

Let’s be clear, battery terminals are the conductive metal connectors on a battery.

 

[Mikerb]

where the confusion lies is in the type of connection. I have build offroad race cars from scratch often used in atrocious wet mud conditions. Yes you can apply dialectric grease in the top of a spark plug boot............but here is the difference.....that connection is really tight, and it is closed at the top so no pushed aside grease could be permanently embedded and unable to clean/remove further into the connector. The battery connectors on our bikes merely work on the basis of a pin ( male) pushing into 2 spring loaded sleeves ( female)........grease can be pushed beyond the male pin length to an area you are unable to reach to clean. The connection is relatively weak. There is no resistance to make or break the connection, it is in fact similar to a standard 2 or 3 pin plug and socket in the house. The bike connector is after all, primarily designed to be easy to connect and disconnect.

 

[Stihldog]

There’s lots of different “lubes n lotions” needed for our eMTB’s. Electrical connections is just another factor to consider. The designers or engineers have hopefully considered the environmental use, but they can't design for everything.

There’s a right or wrong use of dielectric grease. It’s a useful product if applied properly in certain situations.




I’m not a chemist!

 

[Anders]

Yesterday it happened again, when going down a quite rough track. I guess the vibrations was to blame.

The problem this time is that it remains, last time it fixed itself. I am unable to turn on the bike. I see that it briefly tries to connect to the phone, but give up before the connection to the flow app completes.

I removed the battery, and there was slight corrosion on some of the connectors.
I removed the corrosion, but to no avail.

I found a Youtube video stating that one version of the battery latch is faulty.


Has anybody here some experience with the issue described in that movie?

I was at the LBS where I bought the bike. They promised to phone me and discuss when they can take a look at the bike, but didn't do so yet. I'm afraid to do too much dismantling myself, in fear of voiding the warranty, so I guess I just have to wait...

I presume it is some kind of connection problem.
I have a youtube video of the LED remote's behavior here:

- YouTube

Enjoy the videos and music that you love, upload original content and share it all with friends, family and the world on YouTube.

youtube.com

Any ideas?

 

[Stihldog]

Yesterday it happened again, , Any ideas?

Here’s what I did to 3 different Bosch bikes. All Treks. One was mine, one was my neighbor’s, one was a friend.

I removed the skid plate. I loosened the 2 torx security bolts that hold the lower bulkhead in position. The lower bulkhead also holds the male electrics plug that connects to the battery, when the battery is in place.

In all three cases, the vibration and/or movement, happened here. Different failures were experienced, but there was a loss, or momentary loss of power from the battery.

In my situation, it was at a specific spot on a gravel fire road (was not a buried flux capacitor), at a specific vibration, in the morning. Go figure???

The solution for all 3; tighten things up. Proper battery alignment. Stop any rattling. Refit and secure the lower bulkhead. I didn’t use any grease …at all! The problem(s) haven’t returned.

 

[Anders]

Thanks. As the bike is under warrany, my LBS (the seller) wants to have a look before I do anything.
I have an appointment there on Tuesday. So in the meantime I'll just clean it and wait...
Pulled out my old Merida from the shed. Its from the nineties. I took it for a spin. Felt awkward the first kilometers, but got used to it fairly quickly.

 

[Anders]

And just to add to the confusion; I just tried another time, an this time it started without any complaints. I'll take it out for a ride tomorrow morning and see how it goes. My thought is that it could have been some moisture somewhere in the wiring harness that now has dried up.

In any case I will keep my appointment with the LBS for Tuesday.