Hi, I'm having a little trouble with the battery pack in my roomba. As a self respecting EV advocate I like the idea of a self propelled EV that cleans the floor for me ;-)
It's been a few months since I last used the Roomba. I don't remember whether the charger has been plugged in the whole time or not. When I went to use it this morning the charger was unplugged and the power indicator did not respond. So I plugged the charger in, the red charging light started blinking, and after awhile it turned green.
It gets maybe 2 minutes run time once the light is green. I've gone through this twice now, charge it to where the light is green and set it going and get 2 minutes of run time.
In the past it would do maybe 20 minutes of run time.
If this were an e-bicyclist or e-scooterist reporting a similar problem I'd be thinking "uh oh, it's likely by leaving the battery off the charger that the battery self-drained and is now damaged and will never hold a charge again". e.g. lead acid batteries if left discharged for awhile don't hold a charge. On the other hand if it's a lithium or NiMH pack then leaving it partly discharged doesn't cause damage.
My question is -- maybe someone knows what kind of battery is in the Roomba battery pack?
Maybe someone knows something about the charging behavior of the Roomba? Like, if the light turns green that should mean its fully charged but maybe it's lying and I'm really supposed to leave it for a long time.
Someone tore into the pack found that it's a 12 cell NiMH pack using C sized cells, and built a replacement pack using ordinary NiMH cells.
http://www.robotreviews.com/chat/viewtopic.php?t=231
Instructions for proper care of the pack ... such as ... Frequent use - Rechargeable nickel-based batteries do best when used frequently. The worst thing for batteries like these is infrequent light use. The Roomba was designed to be used frequently; this will keep the battery healthy. Hmm, I don't remember an admonition like that about NiMH packs for bicycles. I'm not sure if that's truly required for a NiMH pack. It gives me an idea though, that I have a pair of SubC NiMH packs which I could connect in parallel and velcro to the top...
http://www.robotreviews.com/chat/viewtopic.php?t=2901
http://www.gordonmeyer.com/2006/10/roomba_battery_.html -- "Do not leave your robot uncharged, ever....When you do this you destroy the battery and it won't ever hold a charge again. "
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Yes, right. The cells in it are NI-MH or NI-CD cells. You also can buy them at http://www.powerworldhk.com/product.asp?cid=106 , good quality and low price .
Somewhere I saw a reset procedure -- unplug the battery for a few seconds, put it back in, and put it on the charger and leave it there. That worked and I got a 20 minute runtime like normal. This sounds a little bit like one of the things I've read the Vectrix owners having to do..
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Yes, I guess the Roomba Vacuum Cleaner Robot travels at about the same speed as a Vectrix in "Resynchronise the charger with the failing cells" - mode!
But you should not complain, at least you don't have to wear a helmet when you revive your Roomba...!
Don't fall off, though!
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I have the same problem. Went to use the Roomba and it lasted like 5minutes. Yes, it had been a long time since I had last used it, but still. The thing is less than a year old!....
I will try this charger trick. I am also curious: Is it possible to drop some Lithium batteries in there? I am very impressed with my LifePO4's on the ebike... Hmm...overvolt the Roomba?!?
There's a whole underculture of roomba hackers. As I'm sure you're already aware the slot the batteries go into is proprietary, the case the cells go into has weird screws, etc .. I would think it'd be easier to drill a hole in the top of the case, snake wires into the case, solder/connect to the place where their battery pack would plug in, and velcro a pack to the top of the case.
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
I hadn't really investigated the actual hacking of it..but I'm going to try the battery/recharge trick tonight. Hey reikiman, if you have a link to a good Roomba forum, let me know. Thanks!
As for the battery backpack, the only downside I see with that idea is that the Roomba won't have as low of clearance under furniture, etc, and may be more prone to getting stuck...keep us posted if you attempt a mod...
Uh Oh... I see a small battery trailer in someone's future... :)
Chortle...
Uh, but.. the Roomba likes to spin in place so a trailer might not work too well. Still...
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Well I have a I-Robot Roomba Discovery Model 4100 I bought as a factory refurb for $129.00 and it works great, even on my deep pile rugs. It came with the white Discovery Roomba, a yellow advanced NiMH battery pack, the 3 hour quick charger, 2 virtual walls and 3 spare filters. The only thing not included is the recharge dock for unattended recharging. But I do not mind having to manually plugging in the charger. Because I clean the robot up after every use plugging it in is not a problem. It was well worth what I paid for it.
Thanks,
Ken Finch