The battery is the one part that wears out and is not a consumable. Whether you can buy a new one depends entirely on which badge is on the robot - and not in the way you would guess.
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iRobot, eufy and Shark all sell first-party replacement batteries for their robots, priced from about $40 to $170 when we checked on 2026-09-21. Roborock and ECOVACS list none in their US accessories stores. Only eufy publishes a capacity figure. Replace the battery when a pack costs well under half a comparable new robot.
Every other part of a robot vacuum is a consumable with a shelf next to it. Brushes, filters, side brushes, pads and bags are all sold openly, priced in the tens of dollars, and covered in our replacement parts guide. The battery is different. It wears out on the same predictable schedule as everything else, and whether you can buy a new one is a question with a completely different answer depending on the badge.
We went and checked. Six manufacturers, their own US parts and accessories stores, on 2026-09-21. The result is the most surprising thing we have found while writing this site, because it runs exactly opposite to how these brands behave everywhere else.
Before anything else: confirm it is the battery
A robot that returns to the dock early, or dies mid-room, is not necessarily telling you the pack is finished. A clogged filter, a wound-up brush or a robot working harder on a dirty floor all shorten a run, and all of them are free to fix.
We are not going to repeat that diagnosis here because it already has its own page. Work through runtime and battery life first, which covers how a lithium pack ages, what a normal drop after two to three years looks like, and how to tell a tired battery from a tired brush. If the robot will not charge at all rather than running short, start at when a robot vacuum will not charge instead. Come back here once you are confident the pack is genuinely done.
Who will actually sell you a battery
This is the table we could not find anywhere else, which is why we built it. Every entry was read off the manufacturer's own US store or support pages on the date shown.
First-party robot vacuum batteries, manufacturers' own US stores, checked 2026-09-21
Brand
Sells a first-party battery?
Price when checked
Capacity published?
iRobot
Yes - a dedicated Batteries category, packs listed per series
About $100 to $170
No
eufy
Yes - model-specific packs with long compatibility lists
From about $40
Yes - 5200mAh
Shark
Yes - Li-ion battery, part RVBAT850A
About $66
No
Roborock
Not found in its US accessories store
-
No
ECOVACS
Not found in its US accessories shop
-
No
Dreame
Could not confirm - its accessories collection would not load for us
-
No
Sources are listed at the foot of this page. "Not found" means we read the maker's accessories store and did not see a robot battery listed - it is not proof that no channel exists, and a support request may still get you one. Part prices are not rendered live like the product prices elsewhere on this site, so treat them as a snapshot and check before buying.
Now read that table against everything else on this site. Roborock is the brand we praise constantly for publishing - it states a suction figure for all seven models it sells, where most rivals state none. Shark is the brand we mark down hardest for publishing nothing - no suction figure on any model, no climb height, no mop lift. And yet Shark will sell you a battery with a part number and a compatibility list ninety models long, while we could not find one from Roborock at all.
What almost nobody publishes
Three figures would let you plan for this properly, and they are missing nearly everywhere.
Capacity. Only eufy states one on the pack we found - a 5200mAh Li-ion battery, described as cleaning up to 180 minutes per charge. No other maker here puts a mAh figure on a robot battery product page.
Cycle life. Not one of the six publishes how many charge cycles the pack is rated for. This is the single most useful number for working out whether a three-year-old robot is halfway through its life or nearly done, and it does not exist publicly.
A parts support window. Roborock's repair policy states only that availability "may vary by product model, production year, and inventory", with no period attached. Nobody else commits to a number of years either. When you buy a robot, nobody is telling you how long it will be serviceable.
Roborock's own repair page does at least set out the route: for products outside the warranty period it says paid repair services may be available and that its support team will give service options and estimated costs on request. That is a real path, but it is a phone call rather than a part in a basket, and you will not know the price until you ask.
The arithmetic that actually decides it
Strip away the sentiment about a machine that has served you well and this is a straightforward calculation with three inputs.
What the pack costs. From the table above, somewhere between about forty and a hundred and seventy dollars if your brand sells one at all.
What a comparable new robot costs today. Not what you paid. Robot vacuum prices fall steeply, and the machine you bought three years ago is frequently matched by something cheaper now.
What the new robot would fix that a battery will not. This is the input people forget, and it is usually the one that decides the answer.
As a rule of thumb: if the pack costs comfortably under a third of a comparable new machine and the robot still does everything you need, replace the battery. If the pack is approaching half the price of a new robot - which is the case for some of the iRobot packs against some of today's prices - you are paying a large fraction of a new machine to restore an old one to exactly the state it was already in.
What a new robot fixes that a battery does not
A three to five year old robot is not merely a current robot with a tired battery. The category moved, and it moved in ways that are easy to list.
Anti-tangle brushes. Described mechanisms like Roborock's DuoDivide and JawScrapers Comb, or a self-cleaning brushroll, are now available at the bottom of the market. If you are still cutting hair off a roller with scissors, that is the upgrade - see rubber vs bristle brushes.
A self-emptying dock. The cheapest Roborock that empties itself now states up to seven weeks into a 2.7L bag. Ten years ago this was flagship-only hardware. See self-emptying robots.
Real LiDAR mapping. Rows instead of random, saved floorplans, no-go zones, room selection. Available now at prices where robots used to simply bounce off walls.
Published climb heights. If your old robot gets stuck on the same threshold every week, a battery will not help. A machine with a stated climb figure might - check our threshold table.
A newer battery in a newer chassis. The replacement pack in an old robot is still going into a machine whose brushes, wheels, bearings and sensors are the same age as the battery you are replacing.
How we picked
Criteria first, products second. These are the things we ranked on, stated before anything is recommended.
We checked each maker's own US parts store, not a marketplace. A third-party pack on a marketplace listing tells you nothing about whether the manufacturer supports the repair.
An absence is reported as an absence, not as a negative. Where we could not find a first-party battery we say we could not find one and name the pages we looked at. That is not the same as proving none exists.
Part prices are quoted with the date they were read. They move, they are not rendered live like the product prices on this site, and you should check before buying.
Picks are ranked on what an ageing robot lacks, not on being the best machine at any price - a self-emptying dock, an anti-tangle brush, real mapping and published figures.
We have not opened any of these machines. Nothing here is a repair tutorial and we do not test - see how we pick.
What we did not do: test any of these machines. We do not own one, we do not have a lab, and nothing on this page is written as though we did. The full method.
Quick picks
Ranked on the published specifications below. Tap a row to jump to the full write-up.
#
Product
Best for
Dock
Price
1
Roborock Q7 M5+The Q7 M5's LiDAR and anti-tangle hardware, plus the self-emptying dock the plain M5 does not come with — and a stated bag capacity to go with it.
The cheapest self-emptying dock with real mapping
Auto-empty dock with a 2.7L dust bag, stated at up to 7 weeks
iRobot Roomba Max 715 PetDual rubber anti-tangle brushes and a 90-day allergen-sealed dock — and the one place iRobot has printed an actual suction number instead of a multiple.
The only Roomba with a stated Pa figure
AutoEmpty dock with a sealed AllergenLock bag, stated at 90 days and 0.7 microns
Dual rubber anti-tangle brushes and a 90-day allergen-sealed dock — and the one place iRobot has printed an actual suction number instead of a multiple.
It is on our budget list and it deserves to be - it is thin, simple and cheap. It is the skip specifically as a replacement for a robot whose battery has died, because almost anything you are replacing will have had mapping and this does not. Going from a robot that cleaned in rows and remembered your floorplan to one that bumps around in a random pattern is a downgrade you will notice daily, and the money saved is not large. Buy it as a first robot, not as a second one.
Questions people actually ask
+ Can you replace a robot vacuum battery?
It depends on the brand. iRobot, eufy and Shark all sell first-party replacement packs for their robots through their own US stores, priced from about $40 to $170 when we checked on 2026-09-21. We could not find a robot battery listed in Roborock's or ECOVACS's US accessories stores. Roborock instead directs out-of-warranty owners to contact support for paid repair options and an estimated cost.
+ How much does a robot vacuum battery cost?
On the manufacturers' own stores on 2026-09-21: a eufy RoboVac pack for the X8 series was $39.99, Shark's Li-ion robot battery was $65.99, and iRobot's packs ran from $99.99 for the e, i and select j series up to $169.99 for the Combo j9+ and j7+. These are not rendered live like the product prices on this site, so check them before ordering.
+ How long does a robot vacuum battery last?
Nobody publishes a cycle rating, so there is no manufacturer figure to quote - and we will not invent one. What we can say is that a robot running daily cycles its battery daily, and a noticeable drop in runtime after two to three years is ordinary ageing rather than a fault. Our runtime and battery life page covers how to tell ageing from a fixable problem.
+ Is it worth replacing the battery or buying a new robot?
Replace the battery when a pack costs well under a third of a comparable new machine and the robot still does what you need. Buy new when the pack approaches half the price of a current robot, or when the old machine lacks things a battery cannot add - an anti-tangle brush, a self-emptying dock, LiDAR mapping or the climb height to get over the threshold it keeps failing.
+ Are third-party robot vacuum batteries safe?
We have no basis to judge any specific third-party pack and will not pretend otherwise. What is documented is the commercial consequence: iRobot states that using parts it did not manufacture will void your warranty, and the other makers take the same line. A lithium pack is also the one component where a bad one fails in a way that matters, so this is not the part to economize on.
+ Which brands are best if I want to keep a robot for years?
On parts availability alone, iRobot, eufy and Shark all sell a battery openly with a part number, which is more than we could confirm for Roborock, ECOVACS or Dreame. Set against that, none of the six publishes a cycle rating or commits to a support window, so no brand here lets you plan properly. Ask the question before you buy rather than after.
