Roomba Charging Errors: What to Check for Battery, Dock, Contacts, and Temperature

Read the full spoken or app message, including the word “Charging.” iRobot’s charging chart treats charging as a system involving the robot, battery, and dock. The same number without that context can mean something else.

Match the code to its app route

The iRobot charging chart routes its legacy codes to the iRobot HOME App and its listed 100-series codes to the Roomba Home App. These number groups identify an app route, not a product-family restriction. The chart does not say that every code applies to every model in its opening family list, so confirm your exact robot and follow its current app and support instructions.

The “Charging Error 11” row is a battery hardware alert while the robot is charging. An operating Error 11 on named Roomba 800 and 900 Series models means the vacuum in the bin is not functioning properly; see Roomba Error 11 while operating. Use the full wording and context to choose the right support path.

Charging Error 121: docked but losing charge

iRobot’s Error 121 page says dirty charging contacts are the most common cause, not the only possible cause. Unplug the dock for 60 seconds, remove the robot, and clean the robot and dock contacts with lightly dampened melamine foam or a cloth. The contacts should have a visible shine. Green or copper-colored contacts are described as damaged; contact iRobot about the robot or dock containing the damaged contact rather than scraping or repairing it.

If the error remains, check both power-cord connections. iRobot then says to reseat the battery, but battery removal is model-dependent: follow the exact Roomba’s approved procedure and do not force a sealed assembly. Contact Customer Care if the alert persists. Error 121 does not identify a defective component by itself.

Check the dock and contacts without guessing

First confirm the cord is firmly connected and the outlet works. Some models or docks do not have an indicator light; iRobot specifically says Roomba 100/1000 on a standard charge dock, 200/2000, and Essentials 1 docks may not show one. A dark dock is not enough to diagnose a failure.

For Error 4 or 5, iRobot says insufficient current can come from the robot, battery, Home/Clean Base, or power cord. It directs owners to secure the cord at both ends and clean accessible contacts. Green, copper-colored, or stuck contacts are described by iRobot as damaged; contact support instead of scraping or trying to repair them.

Use recovery steps only for the listed models

For a Roomba 100/1000, 200/2000, Plus 400, Plus 500, or Max 700 that shuts down after leaving the dock, does not gain battery percentage, or is unresponsive, iRobot documents a ship/sleep-mode procedure: remove the robot from the dock, place it on a level surface, hold POWER for at least 30 seconds, release it, confirm no lights appear, and return it to the dock within four minutes. The robot may take more than 30 seconds to boot. This is not a general reset for every Roomba.

iRobot’s reboot instructions vary by family and app. A reboot is different from a factory reset; the latter erases saved data. Do not use a button sequence from another series.

Battery and service boundary

iRobot recommends using batteries it identifies as genuine and warns about aftermarket batteries in its charging materials. That is the manufacturer’s policy, not a complete compatibility guide. Equal battery capacity does not prove interchangeability: iRobot’s battery information says the 100/1000 and 200/2000 families use same-capacity batteries with different shapes.

Do not open, puncture, or repair a battery. Stop using and charging a battery that is hot, swollen, leaking, or damaged. If the error persists after the exact model’s documented checks, contact iRobot with the full alert, robot and dock model, and steps already tried. A charging error is not by itself proof that a battery or dock should be replaced.