Advice on buying a dead Carrera Crosscity e

[Zoradzo]

Hi all

I am a complete newbie to ebikes and no nothing about it in terms of the technicals.

I am currently considering buying a foldable Carrera Crosscity e bike from fb marketplace at a very cheap price as the description says the battery is dead.

Am I naive in thinking that I can just buy a replacement 2 pin battery for it from ebay and that will resolve the issue and the bike will run again or is there usually other problems that I haven't accounted for.

As mentioned, I am very new and green to ebikes but I want to learn to fix and maintain my bike when I get it so it can have a long life and I can become smarter in maintenance as well.

Please let me know your thoughts.

thanks
Z

 

[Peter.Bridge]

Welcome
Is it this one ? https://www.ebay.co.uk/itm/386974269338?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=-4xirrdcrge&sssrc=4429486&ssuid=e7wJGK-DRD6&var=&widget_ver=artemis&media=MORE

I had a search in the forums here (best to do a Google search of this site rather than use the forum search), there seemed to be a few problems with that model

There are compromises you have to make if you want a folding bike - how do you intend to use it ?

 

[saneagle]

Hi all

I am a complete newbie to ebikes and no nothing about it in terms of the technicals.

I am currently considering buying a foldable Carrera Crosscity e bike from fb marketplace at a very cheap price as the description says the battery is dead.

Am I naive in thinking that I can just buy a replacement 2 pin battery for it from ebay and that will resolve the issue and the bike will run again or is there usually other problems that I haven't accounted for.

As mentioned, I am very new and green to ebikes but I want to learn to fix and maintain my bike when I get it so it can have a long life and I can become smarter in maintenance as well.

Please let me know your thoughts.

thanks
Z

Make sure that you test the installed battery before buying a new one. I'd be surprised if the battery is actually dead.

 

[Zoradzo]

Welcome
Is it this one ? https://www.ebay.co.uk/itm/386974269338?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=-4xirrdcrge&sssrc=4429486&ssuid=e7wJGK-DRD6&var=&widget_ver=artemis&media=MORE

I had a search in the forums here (best to do a Google search of this site rather than use the forum search), there seemed to be a few problems with that model

There are compromises you have to make if you want a folding bike - how do you intend to use it ?

Thank you. That link is expired but I found another link on ebay for batteries that's about £224

 

[Zoradzo]

Make sure that you test the installed battery before buying a new one. I'd be surprised if the battery is actually dead.

Thanks for this. How do I test a battery? Is there a specefic kit i need?

 

[saneagle]

Thanks for this. How do I test a battery? Is there a specefic kit i need?

All you need is an ordinary multi-meter and a screwdriver.

 

[Zoradzo]

All you need is an ordinary multi-meter and a screwdriver.

thank you. Would this do?

https://www.amazon.co.uk/ULTRICS%C3%82-Digital-Multimeter-Voltmeter-Ammeter/dp/B00TM0W8ZY/ref=sr_1_5?crid=1KIWWNOFF8S92&dib=eyJ2IjoiMSJ9.X6o1VlX0vIhkRUDEM-oSfMpHjwf6kX23q50RHzTjbv_OytlatRD7j0eqrfQM8Cqw91OSKCjRVC5NvEx9DZkmA-w3FlGcSohYLsqbSTp3FV-ms-8wz59vj4sgMnlz0mvnsgv9SKSDoh69T86W3PPDhpiri6zAlBx0uN6WnPC6bGB7cc697PRngP-aEVuC7ZUi8ekGszxXe2PeHPtVzfw9xpsybaQyoFrLFC-Wl9IalHaCLY37eoHQIucSBKdWeyvhqt5vu74nbkmpM38rzkzEn1jHhNu0owEuP8JgGaYtz8c.QCCDM5UoYCd8-RvZ-UJIIebxRdiNnoi9jINA18RQcYQ&dib_tag=se&keywords=multimeter&qid=1716031001&sprefix=multim%2Caps%2C82&sr=8-5&th=1

I'll have a look at some videos on YouTube on how to use a multimeter

 

[thelarkbox]

thank you. Would this do?

https://www.amazon.co.uk/ULTRICS%C3%82-Digital-Multimeter-Voltmeter-Ammeter/dp/B00TM0W8ZY/ref=sr_1_5?crid=1KIWWNOFF8S92&dib=eyJ2IjoiMSJ9.X6o1VlX0vIhkRUDEM-oSfMpHjwf6kX23q50RHzTjbv_OytlatRD7j0eqrfQM8Cqw91OSKCjRVC5NvEx9DZkmA-w3FlGcSohYLsqbSTp3FV-ms-8wz59vj4sgMnlz0mvnsgv9SKSDoh69T86W3PPDhpiri6zAlBx0uN6WnPC6bGB7cc697PRngP-aEVuC7ZUi8ekGszxXe2PeHPtVzfw9xpsybaQyoFrLFC-Wl9IalHaCLY37eoHQIucSBKdWeyvhqt5vu74nbkmpM38rzkzEn1jHhNu0owEuP8JgGaYtz8c.QCCDM5UoYCd8-RvZ-UJIIebxRdiNnoi9jINA18RQcYQ&dib_tag=se&keywords=multimeter&qid=1716031001&sprefix=multim%2Caps%2C82&sr=8-5&th=1

I'll have a look at some videos on YouTube on how to use a multimeter

We all had to pick up a meter for the first time.. Check out you tube for ebike battery voltage testing too

That meter will be fine for dc voltage testing, Not much to it, select DC Voltage (V=) on the meter dial, use the red probe to probe the positive battery terminal and the black probe to probe the negative battery terminal, and read the voltage off the display, test out with a few aa cells if unsure..

the ebike battery is Much more powerful so just take care not to short it out (do not connect its + and - terminals directly under any circumstances!!)

To test a battery just charge it fully, and when fully charged, Disconnect from the charger and turn off the charger. Once disconnected you can test the battery voltage. A voltage of 41-42v would indicate a very healthy battery.
If significantly lower, it may just need balancing? but it could also be 'used up'

Youtube may tell you Balancing the battery is 'simply' leaving it plugged into power after fully charged.. HOWEVER While this can fix an imbalanced battery, It can also make matters significantly worse for a number of other issues and in the worst case if left unchecked FIRE!!!

So.. report back here if you have a low voltage first..

 

[Zoradzo]

We all had to pick up a meter for the first time.. Check out you tube for ebike battery voltage testing too

That meter will be fine for dc voltage testing, Not much to it, select DC Voltage (V=) on the meter dial, use the red probe to probe the positive battery terminal and the black probe to probe the negative battery terminal, and read the voltage off the display, test out with a few aa cells if unsure..

the ebike battery is Much more powerful so just take care not to short it out (do not connect its + and - terminals directly under any circumstances!!)

To test a battery just charge it fully, and when fully charged, Disconnect from the charger and turn off the charger. Once disconnected you can test the battery voltage. A voltage of 41-42v would indicate a very healthy battery.
If significantly lower, it may just need balancing? but it could also be 'used up'

Youtube may tell you Balancing the battery is 'simply' leaving it plugged into power after fully charged.. HOWEVER While this can fix an imbalanced battery, It can also make matters significantly worse for a number of other issues and in the worst case if left unchecked FIRE!!!

So.. report back here if you have a low voltage first..

thanks for this. And what do you mean by this statement:

"do not connect its + and - terminals directly under any circumstances!!"

thanks for all the help guys. I'm enjoying learning all this new info

 

[saneagle]

thank you. Would this do?

https://www.amazon.co.uk/ULTRICS%C3%82-Digital-Multimeter-Voltmeter-Ammeter/dp/B00TM0W8ZY/ref=sr_1_5?crid=1KIWWNOFF8S92&dib=eyJ2IjoiMSJ9.X6o1VlX0vIhkRUDEM-oSfMpHjwf6kX23q50RHzTjbv_OytlatRD7j0eqrfQM8Cqw91OSKCjRVC5NvEx9DZkmA-w3FlGcSohYLsqbSTp3FV-ms-8wz59vj4sgMnlz0mvnsgv9SKSDoh69T86W3PPDhpiri6zAlBx0uN6WnPC6bGB7cc697PRngP-aEVuC7ZUi8ekGszxXe2PeHPtVzfw9xpsybaQyoFrLFC-Wl9IalHaCLY37eoHQIucSBKdWeyvhqt5vu74nbkmpM38rzkzEn1jHhNu0owEuP8JgGaYtz8c.QCCDM5UoYCd8-RvZ-UJIIebxRdiNnoi9jINA18RQcYQ&dib_tag=se&keywords=multimeter&qid=1716031001&sprefix=multim%2Caps%2C82&sr=8-5&th=1

I'll have a look at some videos on YouTube on how to use a multimeter

Perfect. No self-respecting ebike owner should be without one. When you have your battery, we'll show you how to test it. It's very easy. Nothing to worry about because you can't get a shock from it unless you drop it and it lands on your big toe.

 

[thelarkbox]

thanks for this. And what do you mean by this statement:

"do not connect its + and - terminals directly under any circumstances!!"

thanks for all the help guys. I'm enjoying learning all this new info

The battery connection points are its 'terminals' one labeled Positive (+) the other Negative(-) a wire or metal tool or any other conductor of electricity touching both terminals simultaneously would 'short out' the battery, this could be very bad.

I am not suggesting you would do this intentionally, but could accidentally if unaware of the hazards.
And while your battery should have pcb fuses to stop things getting out of hand putting the fuses to test could possibly blow them requiring more work replacing them.

Ebike batteries contain a BMS (battery management system) a Pcb with electronics to charge balance and protect the batteries cells. Fuses to protect against short circuits are part of the protection. And most accidental shorts are accompanied with a few sparks and possibly a bang making the person responsible jump breaking the short before any fuse has had the chance to blow etc.. (yes, experience talking)

And there is the potential for worse, so .. here is a vid of the worst encouraged to happen..

 

[Zoradzo]

Perfect. No self-respecting ebike owner should be without one. When you have your battery, we'll show you how to test it. It's very easy. Nothing to worry about because you can't get a shock from it unless you drop it and it lands on your big toe.

Thanks saneagle

 

[Zoradzo]

The battery connection points are its 'terminals' one labeled Positive (+) the other Negative(-) a wire or metal tool or any other conductor of electricity touching both terminals simultaneously would 'short out' the battery, this could be very bad.

I am not suggesting you would do this intentionally, but could accidentally if unaware of the hazards.
And while your battery should have pcb fuses to stop things getting out of hand putting the fuses to test could possibly blow them requiring more work replacing them.

Ebike batteries contain a BMS (battery management system) a Pcb with electronics to charge balance and protect the batteries cells. Fuses to protect against short circuits are part of the protection. And most accidental shorts are accompanied with a few sparks and possibly a bang making the person responsible jump breaking the short before any fuse has had the chance to blow etc.. (yes, experience talking)

And there is the potential for worse, so .. here is a vid of the worst encouraged to happen..

brilliant. Thank you for all the info