I've written about the robotic cleaning appliances from i-Robot before ( here, here, and here) but this time I'm writing with an important tip for Roomba and Scooba owners.
Do not leave your robot uncharged, ever.
Lately, whenever I left town, I'd unplug the Roomba's charging unit. When you do this the battery eventually drains, and then it sits uncharged until you plug it back in again, right?
Wrong.
When you do this you destroy the battery and it won't ever hold a charge again.
iRobot tells you this, (here and here) and woe unto you who ignore (or forget) this advice. I can show you the receipt for my $50 replacement battery if you want proof. (I tried resetting the Roomba's power manager to no avail, if you find yourself in this situation, give it a try before replacing the battery.)
If you won't be using your Robot for a while, the correct thing to do is to completely remove the battery, per one of the articles linked to above.
Ugh. But I still loves our Roombas. And the new Scooba is working out well so far. (More about the Scooba after I've used it more.)
Thanks for putting this article together, complete with the iRobot links. It's very helpful!
Posted by: Langley | January 13, 2007 at 11:49 AM
Thanks for the information and links. I just tried the power cycle trick as listed in your links.
Thanks again.
Posted by: Patrick | October 23, 2007 at 09:15 PM
Yes this is true. We left it unplugged for 2 weeks, and now it can only managed 15 mins. It was only 6 months old. Rip off.
Posted by: T | November 14, 2007 at 03:47 PM
You should call iRobot tech support for warranty service.
Posted by: Gordon Meyer | November 14, 2007 at 04:03 PM
I left mine plugged in and that also destroyed the battery.
Posted by: Peggy-Gail Forehand | July 21, 2008 at 10:40 AM
How long should a roomba battery run before it is out of juice? Mine only runs 30-40 min at a time.
Posted by: Trish | July 24, 2008 at 04:51 PM
You can recharge a "dead" Roomba battery as long as there are no shorted or reversed cells. Even then, it may still be possible to recover the majority of its capacity. The Roomba uses 12 NiCad cells in series (nominal 14.4 Vdc). Remove the battery and turn it over. There are 3 slots on the bottom side of the longest extension arm of the case. The slot closest to the pack is negative, the one furthest is positive. I use a DC power supply and set the output voltage at 17.5 and current at 220 maDC and connect the output to the slots indicated above. To clear a short or start a reversed cell back in the right direction, increase the output current to 1000 maDC and monitor the voltage. It should ramp up fairly quick. When it reaches 16, you can be pretty sure it's going well so back down to 220 maDC. That's the optimum rate for 24-48 hours. Check on the battery from time to time to make sure the battery is not hot (a little warm is OK). After 24 hours or so, reinstall in the Roomba and let it dock on it's homebase. It make take another 24 hours until the charge light goes from blinking red to solid green, but the battery will recover. NiCad batteries are different from lead batteries. NiCads store the charge in the plates, not the electrolyte. Therefore they can be stored uncharged. In fact, OEMs receive NiCads in a discharged state. NiCads are also different from NiMh. The NiMh is intended to be used immediately after charge...they don't store or trickle worth a flip! This comes from 45 years of designing battery operated commercial devices...
Posted by: Tom Burnet | September 14, 2008 at 06:02 PM
Ohh, I wish I would have read this before...I could not understand how something only 1 year old could have such a bad battery, but now I know since I did let it uncharged for a about 2 weeks. The batteries are so expensive!!! And, I have not used my Scooba in months (and it's not in the charger), so I can expect to have to buy a new battery for that one too...:( Thanks for the information!!
Posted by: Dania | November 01, 2008 at 05:43 AM
This site has been helpful so maybe you can give feedback on the problem I am having with my roomba. I unplugged the roomba, it discharged and would not hold a full charge so I bought another battery from Irobot. It worked well for about 2 weeks then would not hold a charge. The more I reset the battery the worse it got until it would not charge at all. I ran the roomba with the new battery every couple of days per instructions so it should have been fine.
Irobot sent me another battery and it is doing the same thing. The specific symtoms are the roomba will be fully charged on the docking station, but will only run for less than 1 minute then the battery light turns red and the roomba stops. If I turn off the roomba, remove and reinstall the battery, the battery light will turn green, the roomba will run less than a minute, stop with a red battery light. If I remove the battery and reinstall it, the battery light will turn green again. What is wrong with this roomba. I have cleaned it, all parts appear normal, wheels turn etc. Do you have any idea what is wrong with my roomba?
Posted by: k wayne | December 31, 2008 at 04:49 PM
Is correct that the dock voltage is 4.9Vdc?? I direct connect the plug into my roomba, it has 22vdc, when the current travel to the pin or plug it have 4.9Vdc in the battery terminal. The problem that I have is the roomba don’t charge up.
Omar from Puerto Rico
Posted by: Omar | January 28, 2009 at 07:03 PM
K Wayne said: "the roomba will run less than a minute, stop with a red battery light. If I remove the battery and reinstall it, the battery light will turn green again. What is wrong with this roomba. I have cleaned it, all parts appear normal, wheels turn etc. Do you have any idea what is wrong with my roomba?" I have exactly the same issue with my Roomba 550, I thought the original battery had just died a natural death so I bought a new one, now I am having the same problems as you are. I really don't want to buy yet another new battery only to find out that's not the problem- does anyone have any idea as to what's going on here?
Posted by: Lynne B | February 26, 2009 at 12:12 PM
I am also having the same problem as Lynne B and K Wayne- only with my scooba. Runs a few minutes then stops with red light. I remove the battery and reinstall- green light comes back and and unit runs for a few more minutes before stopping again. Repeat, repeat, repeat until I lose patience. Has anyone figured out a solution?
Posted by: Joetta S | August 17, 2009 at 10:03 PM
I have bought 3 new batteries, all with the same result:
The specific symtoms are the roomba will be fully charged (directly into wall), but will only run for less than 1 minute then the battery light turns red and the roomba stops. If I turn off the roomba, remove and reinstall the battery, the battery light will turn green, the roomba will run less than a minute, stop with a red battery light. If I remove the battery and reinstall it, the battery light will turn green again. What is wrong with this roomba. I have cleaned it, all parts appear normal, wheels turn etc. Do you have any idea what is wrong with my roomba?
Posted by: Kate | October 10, 2009 at 05:15 PM
Same battery probs...green light, hot battery (??) then I turn him on and he shuts down in 4-5 seconds! Battery is new-- about 6 months old, use 15-20 times... Looks like no one has an answer though :-(
Posted by: Sherri | March 28, 2010 at 01:20 PM
I have same problem, battery charged, roomba starts and stopps immediatelly with red light...
How to solve this? Obviously new batery wont solve this.
Posted by: Tom | May 27, 2010 at 03:45 AM
Actually, Tom, that is the symptom of a bad battery. Read the Roomba articles that are linked up.
Posted by: Gordon Meyer | May 27, 2010 at 08:56 AM
I have same problem. Looks like it charges - green light on, but when I start it, it immediately stops with buzz and red light. Before this I did the "reset" trick a few times and battery still worked... Not sure if that has anything to do with this problem just thought I'd mention it.
For this problem, not running at all after charge, I put the charged battery from my 2nd roomba in it and it worked great... The 1st battery, even though 1st roomba indicated it was charged was not actually charged when I tried in my 2nd roomba.
I then "charged" the second battery that worked in the bad roomba and after a long time charging it did go green, but when I said "clean" it did same thing, immediately stopped. I put the battery back in my 2nd roomba and it charged ok. So does not seem to be the battery.
Looks like it is something in the charging circuit to me.
Probably needs to go into iRobot shop, but not sure how much that will cost... anyone? or maybe get a new one - although it still cleans fine and I like having 2 of the same series.
Posted by: Andy | July 05, 2010 at 03:33 PM
Well, Irobot tells me that even if you pull the battery out of the roomba and don't keep it charged, it will eventually drain and kill itself. I've had one in a box for a while, and it appears iRobot is right. It won't hold a charge either. So pulling it from the robot won't help. If you have more batteries than robots, apparently you need to change them out every month or so to keep this from happening. Has the Roomba become more trouble and more expensive than it's worth? Pretty much.
Posted by: Howard Beale | August 23, 2010 at 10:24 AM
OK...here is what I did...3 Roomba batteries....all dead. The Roomba was flashing red then would go green...Roomba would not even power up after charging for 3 days...so...bought a multimeter...cut the end off of the grey Roomba APC charger...added a red and a blue male quick disconnect to each of the wires...the negative wire on my APC was the one with the faint writing on it...the positive was solid black. I then followed the advise "The slot closest to the pack is negative, the one furthest is positive."
and attached the wires...the batteries all charged up to 16.6 VDC and run for an hour or better...I charged them from dead to full in less than 3 hours each. I hope this helps someone else
Posted by: Dari | October 18, 2010 at 04:19 PM
Dari...about the multimeter idea. Isn't a multimeter just a voltage tester? How did you use it.
Does anyone know what voltage should be coming out of the Roomba charger? Is there any way to test the batteries....or the charger itself?
Thanks.
Posted by: Bruce | March 16, 2011 at 01:56 PM
Well my roomba is roughly one year old and it was used approximatelly four times before the charm wore off. We left it on the charger for about 8 months in a closet, and just decided to run it again. It lasted roughly five minutes before demanding recharging. I would have thought an 8 month charge would be sufficient. Laughing here. So, even if you leave the thing on the charger forever, the battery still loses its punch after a year....unused. The Roomba has never been left uncharged the entire time.
Posted by: Cynthia | April 12, 2011 at 11:20 AM
Hi, The two links under "here and here" (above, in the sentence "iRobot tells you this, (here and here)...") are now broken. Do you have replacement sources for this information? Thanks!
Posted by: KA Healy | February 09, 2012 at 04:44 PM