iRobot Roomba Battery pack rebuild

Roomba Battery mod
Rebuilding iRobot Roomba NiMH battery pack
This page is about rebuilding Roomba’s battery pack.
After about 90.5-2 years of regular use and charge, Roomba will gradually start decreasing its working time till a point it will stop working in a middle of its cleaning cycle. This is the point where you should start consider replacing the battery pack.
You may purchase a new genuine iRobot 3000mAh battery pack for ~US$70 (July 2014), a 3rd party pack for a little less, OR you can rebuild your own pack for half the price and get better capacity.

This page describes Roomba 560 but it is the same for all 5xx 6xx 7xx 8xx series models that uses the shown type of battery pack
DISCLAIMER - Important!
Suggested tools and materials:
Hand tools such as pliers, screwdrivers, x-acto knife etc.
- Solder iron and related soldering tools and materials / Spot welder
Note: Since this article was first published, I improved the batteries tab soldering and instead of soldering, I now use “Spot-Welder“. There are many DIY guides on how to build a cheap mini spot welder for this job using a super-capacitor. The results are cleaner, flatter and faster to perform than those made by soldering.
- Hot-air gun.
- Hot-glue gun
- A multimeter / multitester / VOM.
- 12x Sub-C NiMH batteries with/without tabs. 3400mAh or higher
- Metal tabs in case the batteries are without tabs.
- 70mm diameter heat shrinkable tube.
it is 110mm width when flat!
You’ll need 180mm (7″) in length for 1x pack. - Some kind of thin adhesive tape in case you don’t have a Hot-glue gun.
Roomba’s battery pack is made of 12x Sub-C 1.2V batteries connected in-series to produce 14.4V.
Batteries are packed in a shrinkable sleeve and includes a special connection part that incorporates a thermistor which protects from excessive heat.
Rebuilding a new pack make use of new batteries and the connection part taken from the fault pack.
You may build a whole new pack using 12x new batteries OR repair a damaged pack by replacing defective batteries.


Note: Image shows 3400mAH NiMH batteries, any mAh may be used based on how much you want to increase working time/battery cost, however, all batteries should be identical.
(-) side has a larger area that makes it easy for the soldering.
Remove contact’s sticker and scratch the metal surface a bit to help the soldering. See note about soldering/spot welding
When done, check voltage on center + and – contacts to verify ~14.4-15.5DCV
Have fun and enjoy your Roomba, Avi
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iRobot Roomba DIY Guides by Avi
9-beep fix | power-supply conversion | speaker fix
5xx-7xx CHM cleaning | 8xx-9xx CHM cleaning
Red CHM mod | Gray CHM mod | battery rebuild
Copyright © Schneor Design. All rights reserved. Do not copy without written consent from the author.
Do you think it would be safe to charge spare batteries outside of the unit?
I have a few that I would like to keep charged and on hand when needed. If I build a rig that charges them outside of the robot, do you think there would be an issue?
NO, if you know what you’re doing and know how to build this rig while keeping all the requirement for charging those batteries.
This is not a simple wiring job, it has to do with a lot more, so do it only if you know your way around.
Good luck