Cyclotricity Battery Issues.

[Nealh]

Bms are not expensive plenty on ali.
https://www.aliexpress.com/item/36V-BMS-3-7V-Cell-10S-PCM-Wholesale-and-Retail-Used-For-36V-Lithium-Battery-Assembly/1339108032.html?spm=2114.search0104.3.74.YnhrfT&ws_ab_test=searchweb0_0,searchweb201602_1_10152_10065_10151_10130_10068_10344_10345_10342_10343_10340_10341_10192_10540_10190_10307_10301_10303_10060_10155_10154_10056_10055_10054_10539_10538_10537_10059_10536_10534_10533_100031_10099_10338_10103_10102_10052_10053_10107_10050_10142_10051_10324_10325_10084_10083_10080_10082_10081_10110_10111_10112_10113_10114_10179_10312_10313_10314_10184_10078_10079_10073,searchweb201603_25,ppcSwitch_3&btsid=a8119887-0f7e-4939-b51e-89eafa47e513&algo_expid=fc9a3d4e-67ef-46c6-b6d8-fd1f2ff96b5b-9&algo_pvid=fc9a3d4e-67ef-46c6-b6d8-fd1f2ff96b5b
https://www.aliexpress.com/item/10S-25A-bms-2017-new-Li-ion-42V-25A-BMS-PCM-with-balance-for-electric-bike/32821307716.html?spm=2114.search0104.3.285.YnhrfT&ws_ab_test=searchweb0_0,searchweb201602_1_10152_10065_10151_10130_10068_10344_10345_10342_10343_10340_10341_10192_10540_10190_10307_10301_10303_10060_10155_10154_10056_10055_10054_10539_10538_10537_10059_10536_10534_10533_100031_10099_10338_10103_10102_10052_10053_10107_10050_10142_10051_10324_10325_10084_10083_10080_10082_10081_10110_10111_10112_10113_10114_10179_10312_10313_10314_10184_10078_10079_10073,searchweb201603_25,ppcSwitch_3&btsid=a8119887-0f7e-4939-b51e-89eafa47e513&algo_expid=fc9a3d4e-67ef-46c6-b6d8-fd1f2ff96b5b-37&algo_pvid=fc9a3d4e-67ef-46c6-b6d8-fd1f2ff96b5b

Though if your Bms is charging ok and full charge is 41.5 - 42v, I would suspect cells are crashing if power cuts off when a decent load is being asked.

 

[Annie B]

I have this exact problem.what was your conclusion and how did you decide to solve the issue?

 

[Annie B]

I haven t managed to sort it. Cyclotricity refuse to answer any of my emails.It seems a common problem.Anybody out there which might know? I've tried a long charge and its static now around 37 v. After a charge.and doesn't lose volts over time unless in use and then drops .it will restart happily when on the flat.

 

[Annie B]

Who not which

 

[Nealh]

Check the charger output voltage one should see 41.5 - 42v, if it is ok then open the battery and measure 10 cell group readings via the sense wire connector which you wil have to unplug.
If all are pretty much the same and balanced then either the cells are shagged or the BMS doesn't allow more charge as 37v is very poor.
One can try to manually charge the cell groups bypassing the BMS to see if they:
1. Charge higher.
2. Hold that charge without self discharging.
If they do both of the above replace the BMS.

 

[Annie B]

I'm having issues with my ebike battery. I am only getting around 10 miles out of it before it die's before 40-50 miles wasnt uncommon. I spoke to Cyclotricity that suggested that I run it compleaty flat and then do a 12hr charge on it 3 times and that will sort it out.

Does that sound true or compleat bull too get me off the phone. Iv'e not found there tech support to be much use in the past so its got me thinking. Bike is around 13 months old and battery has done 2k miles. I had the rear motor changed out around 1500 miles as it kept cutting out.

 

[Annie B]

Did the rear motor change sort the problem out?

 

[D C]

Did the rear motor change sort the problem out?

I doubt you'll get a reply as it's an old thread and he's last seen over two years back.
Dave.