I've written before about my tribulations with a Roomba battery. Last week I had an important new development that took a few hours to track down, so I want to share what I've learned.
Shortly after using my Roomba Discovery, and after I hooked it to its charger, I noticed that the power light was flashing red. (Normally it glows red while charging, this was a distinct flash.)
I turned to the iRobot tech support site, exchanged several emails with tech support, and called them once. I'll save you the gory details and cut to the chase.
Flashing red indicates a problem with battery charging. Either the charger is bad, or the charging circuit in your Roomba is bad. In my case, the green light on the charger apparently indicated it was the internal circuit in the Roomba. The worst possible scenario, in other words.
I solved this problem by buying an external rapid-charger for Roomba batteries. They're discontinued by iRobot, but the one I ordered arrived in brand-new condition and works like a champ. There's a minor hassle-factor with having to remove the battery to charge it, but it keeps my robot working and doesn't cost much, so I'm happy.
My experience with iRobot over this matter wasn't as good as I'd hoped:
iRobot won't repair a broken Roomba, but they did offer me a discount on a discontinued model, without any accessories. The prices were disappointingly high, and I wasn't eager to shell out that much for an obsolete model. Instead, I asked for a discount on a current model. The offered 20% on their current intro robot, but this was still more expensive than a mid-line robot at Costco.
Via email, tech support told me that I'd have to replace the robot but didn't offer any explanation at all, which made me doubt their diagnosis. When I called, the rep I spoke with insisted that a flashing power light is normal, and that nothing was wrong with my robot. This is clearly not the case, and it was frustrating that he had to talk to a higher-level person to confirm such a simple fact.
I believe the flashing red charge light is normal. When I first received my roomba and plugged it in, I got a flashing red power light. The next morning it had switched to the regular pulsing charge light. That night it was green, and roomba has been working a treat since.
Posted by: Ryan | March 18, 2008 at 11:15 PM
Sorry, Ryan, I've had 3 Roombas. None of which flash the charge light. The tech support documents at Roomba.com also agree that a flashing light is a sign of a problem. Glad that it worked out for you, though, and thanks for your comment.
Posted by: Gordon | March 19, 2008 at 08:16 AM
My mom gave me her old Roomba Discovery and said that if I could figure out what was wrong with it, I could keep it. The problem was that there was a flashing red light when it charged, and it would not keep a charge. I now know what I need to do to fix it. Thanks!
Posted by: Jessica Karels | February 02, 2009 at 06:56 PM
Well I wish mine had worked but the first time I pluged the darn thing it I got the red flashing light and to date have owned the stupid thing for 3 years and still not goten it to sweep my floor once. Finaly thought of going on line to find out why the red flahsing light wich isnt in the book was happening. There tech help sight was no help and Wife bought it through HSN and had not kept the papers from the purchas so I just threw the darn thing in a closet. Thank you for your idea maybe I can make it work would be nice. Thanks
Jay
Posted by: Jay | June 02, 2009 at 08:18 PM
What roomba battery model are you using with the rapid charger described above. I want to make sure it will work properly with our unit. Thanks.
Posted by: Ben Lozada | September 04, 2009 at 05:11 PM
Have another read. The second paragraph says I'm using a Roomba Discovery.
Posted by: Gordon Meyer | September 05, 2009 at 11:25 AM
Our roomba will not hold a charge all of a sudden. It is plugged in all the time. It works about 5 minutes then dies. We looked on line and it was suggested to take the battery out, and hold the power button for 30 seconds, replace the battery and charge for 72 hours. WE did this and it blinked red for about an hour then went green.Not sure if it will work
Posted by: Donna Tatum | September 10, 2009 at 08:20 PM
Ms. Tatum's post was very helpful. My roomba had the same problem. Ms. Tatums solution seems to have worked.
Posted by: twitter.com/pigbotx | October 14, 2009 at 10:28 PM
I will try Ms. Tatum's suggestion. I have the same problem and REFUSE to contact Roomba or HSN - both were horrible experiences after I first purchased the Roomba and things were breaking immediately = (
For such a wonderful concept, the quality is exremely poor and the service is even worse!
Posted by: C. Lou | November 24, 2009 at 09:04 AM
My Roomba sat on the base/charger for several weeks. When I went to use it, it would not work. I ordered a new battery. It ran for like 3 minutes on the new battery and stopped. I suffered through phone calls and emails with iRobot's support only to be told it was the charging mechnisn and to order a new roomba. I didn't. Now I am condidering the external rapid charger, but I'd like to explain what mine does and see what you think. It takes many hours for it charge on the base but it does turn green. When I turn it on...NOTHING. Then the charging light is red again as if it was never charged and it takes several hours (I leave it for like 16+hours) to turn green again. But again, nothing and it goes to red again. It does this with the new battery and the old battery. Does it sound like a charging problem? I sent the new battery back and got a refund. I only have the old battery now. Think the external charger may be the answer? Or might I need the external charger and a new battery? Again, I left the old battery sitting on the base/charger for a long time (like 2 months). Or might it be something else all together???
Posted by: Sophia Barnes | March 21, 2010 at 03:38 PM
I got a NIB roomba Discovery system for $35 a couple of weeks ago. I hooked up the fast charger. It looked like it charged fully over night. Had the green steady light. When I turn on the power I get the "needs charging" tone. I reset by removing the battery and holding the power button for 30 seconds. Charge for three days. Same result. I checked the battery voltage... barely 12v. I bought a new battery from a vendor... 3300 ma.. exact same design. Long story short... same result. I am a hobbyist and know how to charge NiMH batteries to 14.4V. Roomba never charged the new battery. I was able to put 3300ma into it. I put in the roomba and off it went for the first time. Looks like it has a bad internal charging circuit. I have a message into support but from the looks of it I won't get much help.
Mike
Posted by: MikeH | August 16, 2010 at 08:57 AM
I put my robot aside from the base charger for a few days. Then when I put it back I had a rapid blinking amber light. I removed the battery and pressed the power button for 30 sec. I put the battery back on and placed the robot on it's base. Now the amber light was slow flashing that was the sign of normal charging.
Posted by: M l | November 13, 2010 at 08:08 PM
I too have had an Irobot for a few years and only got to use it for a week or so before it quit working on me. I have reset the battery and everything, to no avail. FOR HOW EXPENSIVE THESE VACUUMS ARE, THEY REALLY SHOULD BE ALOT MORE RELIABLE!!! RIPOFF!! RIPOFF!! RIPOFF!! THE IROBOT MANUFACTURERS ARE CROOOOKS!!! NOBODY BUY AN IROBOT!! THEY'RE CRAP!!!!!!
Posted by: Adam | December 20, 2010 at 01:50 PM
If your problem is that a battery suddenly starts to not hold a charge. and you try the solution mentioned by Ms Tatum, and that does not work, try it again. If still no improvement, it is likely one of two things. The battery has a dead cell in it (note the whole battery is not dead if it runs for a few minutes -- they are nothing but a bunch of C-cells packaged together and one has failed), or the charging system in the Roomba is defective. Two people mentioned they got a new battery, used it once, then same result. In that case, it is almost certainly the internal charging circuit. Search online about this. I don't believe it can be repaired even moderately easily, or I would have done so. That Roomba will keep working 100% fine on a charged battery. But do NOT try to charge a battery with that Roomba - the circuitry will drain it and likely permanently damage the battery (new or old). That's why an external charger (or charging it in another Roomba) will solve the problem. By the way, dead cells in a battery pack can be replaced with some effort (I've done it across the 5 years or so I have been using the Roombas) or new battery packs are available. Info is available online for both.
Posted by: Zinco | January 16, 2011 at 06:00 PM
i have the same exact issue as Sophia Barnes above. i even bought a 2nd battery, but i kept it. it's actually been a yr or so since i've had the issue and decided to get the roomba out and try one more time (we just got a 2nd white cat, so i thought i should try. ha).
i'll try the reset thing and if that doesnt work, i'll try that external charger....if that doesn't work, either i totally killed the batteries by trying to charge them in the roomba or the roomba is just toast.
Posted by: dh | January 24, 2011 at 07:24 AM
My charger on our roomba was blinking green but the device on the the floor had no light at all. I plugged the charger directly into the roomba and nothing.I found a charger from one of my drills or the computer that fit into the charging holes and and has seemed to work. The original charger is bad even though its green light still blinks. I am wondering if the different type charger can damage the machine.
Posted by: R. Bowen | April 16, 2011 at 02:05 PM
I hope you got your Roomba problem fixed. I know it was a frustrating thing for me when mine broke down
Posted by: Roomba Guy | June 27, 2011 at 08:00 AM
I don't understand what Ms. Tatum means by holding the power button after removing the battery. What power button? How will this work if there is no battery? I am having the same problem. My Roomba runs for about 5 minutes and then says that it needs to be charged. So, I am hopeful about Ms. Tatum's fix but I don't know how to do it.
Posted by: Lisa | November 13, 2011 at 10:29 AM
I picked up an abandoned Roomba in the area of my building reserved for people who leave things they don't want for anyone to pick up. Came with the dock, power transformer and two virtual wall adapters. When I plugged it in it flashed red for some time, then it turned green. Apparently flashing red is a special mode triggered by the robot when it hasn't been used in some time. Weird. It works fine.
Posted by: Juan | November 27, 2011 at 04:30 PM
Lisa, pressing power button without baterry discharges memory like a computer.
Posted by: Luis Freitas | January 14, 2012 at 07:02 AM
I have just been given a roomba 500 series. When I first got it and plugged it in nothing happened. then I plugged it in a couple of days later and the green light came on the dock and power unit and all seemed to be charging. Then I moved it - all stopped. I unplugged and replugged it then the green light on the power unit and the green light on the dock started flashing. it isn't charging, there are no lights on on the roomba unit - anyone any ideas?
thank you
Posted by: Pauleen | January 21, 2012 at 11:24 AM