A solution for a Roomba that won't charge

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.

Comments

[Ryan]

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.

[Gordon]

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.

[Jessica Karels]

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!

[Jay]

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

[Ben Lozada]

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.

[Gordon Meyer]

Have another read. The second paragraph says I'm using a Roomba Discovery.

[Donna Tatum]

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

[twitter.com/pigbotx]

Ms. Tatum's post was very helpful. My roomba had the same problem. Ms. Tatums solution seems to have worked.

[C. Lou]

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!

[Sophia Barnes]

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???

[MikeH]

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