(31 customer reviews)


14.4v NICD 2000MAH Replacement Battery for Roomba 400 Series

Availability: In stock

The ML-RMB400 Replacement Battery by Mighty Max is Designed for for iRobot Roomba APS 400 Series, Its an Ni-Cd Rechargeable battery that keeps Roomba running at peak performance, cleaning up your room in a single charge.  ML-RMB400 can be charged or discharged as needed without loss of capacity.
The ML-RMB400 battery is fully compatible with all Roomba FloorVac models: iRobot Roomba 400 Series, Discovery Series, Create Models and Dirt Dog Models.
Battery Specifications:
Voltage: 14.4V
Amperage: 2000mAh
Chemistry: Ni-Cd
Warranty: 1 Year


Amp Hour







1 Year








2.00 Lbs

31 reviews for 14.4v NICD 2000MAH Replacement Battery for Roomba 400 Series

  1. Angie McElhannon

    Works just as it should


    almost as good as OEM

  3. Customer

    Right out of the package, brand new, the Mighty Max Battery powered our Roomba for at least 30 minutes without having to charge it first. We have a 2007 Roomba that’s been inactive for at least five years and now it’s good as new. So far so good.

  4. Customer

    Perfect fit

  5. cinbugg

    Fits perfectly and works. We will have to see if it continues to work well.

  6. W. M. Murphy

    It looks exactly like the OEM battery and the power output is on par with the original. After having for a month, still running daily like a champ.

  7. Viktor Vaughn

    The battery was going on my 2007 iRobot Dirt Dog and would run for 20 minutes or less. This replacement battery works perfectly and the iRobot runs like new again.

  8. Marco Carmona

    Exactly what I needed

  9. P Fowler

    Snapped right in, charged quick, good response

  10. Darlene Brzoza


  11. Customer

    This has been an excellent replacement battery for our roomba. We have tested it several times to see if it will hold the charge and it has not disappointed so far. Our vacuum is back in business!

  12. Gregory

    My vacuum is back in business!

  13. Leslie C.

    Fit my Discovery and got it back to cleaning. Exactly what I needed!

  14. Customer

    Great! Vacuum works great!

  15. Lassie101

    I hadn’t used my Roomba discovery for about 8. Years and bought the battery and now it works great.

  16. Rommaq

    Awesome! Got it as promised. working like a charm!!

  17. carole wicker

    The replacement battery gave new life to my old I robot.

  18. jATSL

    I have a 2007 IRobot I didn’t think I’d ever be able to use again. My son found this battery replacement & it works like new.I charged the battery overnight & it’s been working perfectly.Never give up on something.Definitely would recommend

  19. Katrina

    Oh to have my machine work again YEA!

  20. Jan

    Works great for my 400 the only issue is it takes over 12 hours to charge.

  21. Customer

    Received when expected and the battery did have a partial charge. I charged fully and my Roomba went to work.

  22. MarcL

    Perfect for my Roomba

  23. DUG

    exactly what was needed

  24. GJ

    Fits perfectly and works just the way it is supposed to.

  25. Maltesefolks

    I am so happy these worked! My roomba is older and I wasn’t sure it would still work. The batteries are perfect and the shipping was great. Thanks so much.

  26. Customer


  27. James

    Works great.

  28. sierra

    i got this for my old roomba, still charging hopes it worksif not i will send it back

  29. Linda Sue Yoder


  30. Customer


  31. gthummer

    I had a older model Romba that was just shelved after the battery would no longer take a charge. I found coming to has saved me $$$ but also several of the projects would have been just thrown out. Either it was to expensive to try and fix or not finding the right part and having to pay for returns. I will update this to let you know how the battery life is.

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