Carrera crosscity E power on issue

Clive Norwell

Finding my (electric) wheels
Sep 16, 2017
7
0
53
Tiverton
Hi All, I bought a 2018 crosscity e bike with a dead battery, it had fallen below minimum voltage to charge, I opened up the battery and charged it by the battery + & -, now when I turn it on it either turns on straight away or the display just flashes and then turns off, if you turn it off via the display and then turn it back on it works fine, if you turn it off via the battery on/off and then try and turn it on again it just flashes one battery bar and then turns off, I have tried unplugging the BMS board and plugging it back in after a few seconds, I've tried electrical spray on the switch, I've short wired the switch to rule that out but still it will not switch on properly, any ideas ?
 

Clive Norwell

Finding my (electric) wheels
Sep 16, 2017
7
0
53
Tiverton
I've tested voltage on the battery at 41.7v, when the display works it all seems fine on pedal assist, the BMS has on/off on it which is my first thought, do you think I have a mix of over/undercharged cell groups which is causing the issue ?
 

Clive Norwell

Finding my (electric) wheels
Sep 16, 2017
7
0
53
Tiverton
Just tested the cell groups as follows
1, 4.13
2, 4.13
3, 4.13
4, 4.13
5, 4.13
6, 4.13
7, 4.13
8, 4.13
9, 4.13
10, 4.14
The cells seem to be ok, the battery charged as I would expect but the on/off issue is baffling me.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
4,742
1,678
Basildon
That's all good then. It must be the display panel. They get water in them sometimes, which can make a mess.

Disconnect the control panel and bridge the red and blue wires. That should give you level one assist without the panel.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
11,114
4,280
57
West Sx RH
Check the switch wiring solder joints, may be a bad joint ?
 

Clive Norwell

Finding my (electric) wheels
Sep 16, 2017
7
0
53
Tiverton
Thanks for the reply guy's, the switch solder is fine, VFR400, it's the combination of turning the bike off by the battery switch that causes the issue, if I turn it off by the control panel then it seems fine and works as it should, if left then when I turn it on the panel flashes once and then turns off, very confusing.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
4,742
1,678
Basildon
When the panel flashes on once, it's because there is no battery connection. what you're seeing is the capacitor discharging that's across the battery wires. It behaves like a tiny battery that can only last for a split second.

You need to find out where the battery voltage is being interrupted. Normal causes are faulty key-switch, faulty key-switch solder joints (always look OK - re-solder them to make sure), bent battery terminals and/or stretched receivers, loose bullet connectors to the controller.
 

Clive Norwell

Finding my (electric) wheels
Sep 16, 2017
7
0
53
Tiverton
I've now managed to sort it I think, left the BMS unplugged overnight and tried it this morning, all seems to be Ok now, have tried it around 20 times with no issues, Thanks for your help vfr400 & Nealh.
 

cyclebuddy

Esteemed Pedelecer
Nov 2, 2016
450
248
Beds & Norfolk
This is a left-field thought...

I watched a youtube video of a guy recelling an ebike battery some while ago. It wasn't a mainstream brand (like Bosch, Yamaha, Shimano etc), but nevertheless, quite a common one found in Europe. Like your battery, the voltage had fallen to a level too low to recharge, but once recelled (or voltage is restored as in your case) there was a common problem of the bike misbehaving. The purpose of his video was to show that (with his specific type of battery/BMS), a memory chip on the BMS logs cell state, and you needed to reset the chip. He did this by temporarily shorting a pin on the chip to earth. It worked.

Maybe leaving the board powerless for a while has done much the same in clearing this memory (if yours had such a chip)?

Glad it's working now though.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
4,742
1,678
Basildon
This is a left-field thought...

I watched a youtube video of a guy recelling an ebike battery some while ago. It wasn't a mainstream brand (like Bosch, Yamaha, Shimano etc), but nevertheless, quite a common one found in Europe. Like your battery, the voltage had fallen to a level too low to recharge, but once recelled (or voltage is restored as in your case) there was a common problem of the bike misbehaving. The purpose of his video was to show that (with his specific type of battery/BMS), a memory chip on the BMS logs cell state, and you needed to reset the chip. He did this by temporarily shorting a pin on the chip to earth. It worked.

Maybe leaving the board powerless for a while has done much the same in clearing this memory (if yours had such a chip)?

Glad it's working now though.
Have you got a link to the video? I've never seen or heard of that sort of thing on normal Chinese batteries, and I've dealt with hundreds. even the smart BMSs don't have a feature like that. I'd like to see what he had.
 

cyclebuddy

Esteemed Pedelecer
Nov 2, 2016
450
248
Beds & Norfolk
Have you got a link to the video? I've never seen or heard of that sort of thing on normal Chinese batteries, and I've dealt with hundreds. even the smart BMSs don't have a feature like that. I'd like to see what he had.
It was a while ago, but I'll see if I can find it again and post if I do. It was a rack battery IIRC. Many smart BMS's (Bosch, Phylion etc) have chips that store number of charges, state of health etc for dealer reading... maybe this logged the fact that the battery was below voltage and un-chargeable. It needed to recalibrate. Bosch totally craps out if you disconnect power, doesn't it? Kalkhoff needs to fully drain and recharge fully for theirs to "calibrate". This guy just shorted the chip briefly to reset whatever it had remembered - it was a hack. The OP did recharge/recover his pack through unconventional means - any memory/charge cycle chip wouldn't know that, as it wouldn't by fitting new cells?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
4,742
1,678
Basildon
It was a while ago, but I'll see if I can find it again and post if I do. It was a rack battery IIRC. Many smart BMS's (Bosch, Phylion etc) have chips that store number of charges, state of health etc for dealer reading... maybe this logged the fact that the battery was below voltage and un-chargeable. It needed to recalibrate. Bosch totally craps out if you disconnect power, doesn't it? Kalkhoff needs to fully drain and recharge fully for theirs to "calibrate". This guy just shorted the chip briefly to reset whatever it had remembered - it was a hack. The OP did recharge/recover his pack through unconventional means - any memory/charge cycle chip wouldn't know that, as it wouldn't by fitting new cells?
The Kalkhoff batteries and some other similar ones have to be run through a complete charge cycle to calibrate the meter - nothing to do with the main functions of the BMS.

Some laptop batteries have BMSs that switch off permanently if they detect certain conditions, including the maximum number of charges. They're reset by bridging the positive cell pack to the positive output wire, but I've never seen or heard of that on an Ebike BMS. Normally, to reset an intelligent BMS, all you have to do is disconnect the multi-pin connector if they don't get a separate positive from the cell pack. If they have the positive wire, you have to unsolder it as well. That's only for BMSs that have a CPU. A lot of cheap and older BMSs don't have a CPU, so they have no intelligence to do anything like that.
 

cyclebuddy

Esteemed Pedelecer
Nov 2, 2016
450
248
Beds & Norfolk
@vfr400: Had a quick look, can't find the video... but it's there somewhere.

Pretty sure it was a Tranzx BL03 rack battery - common on German Winora and Hercules bikes, big manufacturer selling only in mainland Europe.

Pretty sure the youtube video was linked to a thread from one of the other forums.

Here's a discussion "TranzX Battery 36V BL03 defective.... Cell swap", pedelecforum.de page 7/8/9. Similar story - of which there are a few - abridged:

User colourful cake: The old BMS has been taken over so that the display display works again. Installed is now 10s5p [new 18650 cells from old pouch totally flat]... 250w engine and 36V...

Now I only have the problem that he shows with a full battery (41.1V) that he has only one bar of the battery on the display...

So maybe a BMS reset could help?... Which of the 5 pins in the charging plug do you have to bridge for how long?

User Tommmi: Connect pin 2 and 5 on the port for 2sec... when the wrong ones have been bridged BMS is also gone.

User colourful cake: I now bridged contact 2 and 5 again with another cable and then it went!... Definitely he now shows the full battery!

User Garret: [theorising] ...then it has to work via the I2C bus... picture is an OZ 890 ( i2C ), where probably reset on ground lies.


IIRC in the video the guy just shorted two points internally to reset the BMS, but I guess it likely amounts to the same thing?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
4,742
1,678
Basildon
@vfr400: Had a quick look, can't find the video... but it's there somewhere.

Pretty sure it was a Tranzx BL03 rack battery - common on German Winora and Hercules bikes, big manufacturer selling only in mainland Europe.

Pretty sure the youtube video was linked to a thread from one of the other forums.

Here's a discussion "TranzX Battery 36V BL03 defective.... Cell swap", pedelecforum.de page 7/8/9. Similar story - of which there are a few - abridged:

User colourful cake: The old BMS has been taken over so that the display display works again. Installed is now 10s5p [new 18650 cells from old pouch totally flat]... 250w engine and 36V...

Now I only have the problem that he shows with a full battery (41.1V) that he has only one bar of the battery on the display...

So maybe a BMS reset could help?... Which of the 5 pins in the charging plug do you have to bridge for how long?

User Tommmi: Connect pin 2 and 5 on the port for 2sec... when the wrong ones have been bridged BMS is also gone.

User colourful cake: I now bridged contact 2 and 5 again with another cable and then it went!... Definitely he now shows the full battery!

User Garret: [theorising] ...then it has to work via the I2C bus... picture is an OZ 890 ( i2C ), where probably reset on ground lies.


IIRC in the video the guy just shorted two points internally to reset the BMS, but I guess it likely amounts to the same thing?
TransX is similar to Bosch, Kalkhoff, etc, that use comms between the controller and BMS. The procedure was probably to reboot the comms system. You don't have that on most Chineses batteries.
 

cyclebuddy

Esteemed Pedelecer
Nov 2, 2016
450
248
Beds & Norfolk
The Winora/TranzX BL03 battery referred to pre-dates the whole TranzX CANbus era by some margin (2017/2018) although it may have used some earlier smarts/comms method. And Halfords say of their Crosscity "As standard on all Carrera E-bikes, the Crosscity comes with an integrated smart control system that protects the battery...", so the OP's battery may not be a totally dumb/basic BMS Chinese cheapy; the inference is there's some smarts in there (all the other Carrera's do).

I dare say you're right though (you usually are).
 

Related Articles

Advertisers