Actions
Forum Thread Details
  • State Not Answered
  • Replies 8 replies
  • Subscribers 304 subscribers
  • Views 2204 views
  • Users 0 members are here
Related
See a helpful answer?

Be sure to click 'more' and select 'suggest as answer'!

If you're the thread creator, be sure to click 'more' then 'Verify as Answer'!

My Vacuum Cleaner Motor Doesn't Work. Could the Battery Management Circuit be the Cause?

jsg

Hello,

I am new in this forum. First of all, I would like send greetings to everybody. I am not a native English person, so I apologize if something is not right written or expressed.

Here is my question:

I have a portable vacuum cleaner that works with a batery that contains 2 cells 18650 Li-on, 2.200 mha each, 7.4V total voltage with BMS included. The device has worked well for some months, but now, when I switch on it (after checking the battery is fully charged) the motor starts turning for less than one second and stops. If I repeat the operation, the result is the same. Seems the BMS is cutting the current to the motor. I checked the connections and dissasembled the motor, cleaned it, but the result is the same. I connected the motor directly to the battery (previously dissassemble the bms) and it works perfect.

I would ask to the community if somebody has experienced this kind of problem and what could be the root cause and, if is possible, what could be the potential solution.

The device data is:

-Portable Vacuum cleaner

-Battery: 2 cells 18650 Li-on, 2.200 mha each, 7.4V serie connected with BMS 20A included

-Total power: 120W

-Power AC adapter (for charging battrty): 8.4V, 1A

 

Thank you in advance!

  • 0

    Welcome. Please, don't concern yourself with mastering English. It is native to my tongue and I am still not very good at it.

    I rolled around you information in my mind and have some questions. My assumption is BMS is AC mains? I'm thinking BMS is an acroymn for building mains supply?

    Before failure confirm the vacuum operated on battery only and AC (with battery)? Would it operate without a battery installed. This may not be something that was checked. Operate, meaning it could be used as a vacuum.

    Now the vacuum operates on battery only and fails on AC(with battery)?

    After operating the vacuum on battery only. The battery can be recharged if plugged into AC. Any attempts to operate the vacuum with AC results in failure.

    Will the vacuum operate without batteries installed? Just running on AC.

  • 0 in reply to colporteur

    I think that BMS is battery management system - the circuit that protects the battery, manages right charging profile, prevents overload and overcharge, ...

  • 0 in reply to Jan Cumps

    OK. That shoots that first trouble shooting sequence to crap. I'll sit on the bench now.

  • 0

    Hello Colporteur.

    Thank you very much for answering my question.

    Let me explain with more detail how works the device:

    BMS means in this case "Battery Management System". It is a small circuit attached to the DC abttery that controls how the DC battery is charged and also give protection to battery life when there is danger of hurting  it. Cuts discharging current to the device when voltage level is too low and also, cuts incoming current to the battery when it is fully charged.

    The vaccum works only with DC current. The battery is charged from an AC/DC charger that is plugged in the domestic electric net of 250V AC and supply to the battery 8.4V 1A DC.

    For some months, the device worked perfect, but now, when I try to use it, only works for one second (more or less) and the power drops or is cut immediatly. I checked the charging process and battery and all works OK. If I disconnect the BMS from the battery and connect directly the motor to it, the vacuum works normally, but I understand the battery should be protected by BMS.

    Let me know if you need any other detail and again, thank you for answering.

    Best Regards

  • 0 in reply to jsg

    Thanks for the response. Can you share make and model? I have (my missus) a battery vacuum, let see if someone doesn't have a similar unit.

  • 0 in reply to jsg

    I hope the link generates some response. According to the Amazon the unit is not available for the Canadian market. For that reason I am out.

  • 0 in reply to colporteur

    Hello,

    I have tried to obtain in English the information about device, but was not possible. I have found it in Spanish. I attach it. Please, let me know if you can read it. Maybe the technical characteristics could be understood enough despite it is in Spanish. If you need additional clarification, let me know.

    Thank you very much!