Battery Platforms
Ryobi 40V vs Kobalt 80V: two batteries, two completely different strategies
Both mowers come with two packs and publish 80 minutes. What happens to those packs while you mow is the whole comparison.
Affiliate disclosure: we earn a commission if you buy through our links, at no extra cost to you. It never changes which product we rank first — here is how we're funded.
We have not tested these units. Every spec on this page comes from the manufacturer's own documentation and is linked to it. Every computed figure is arithmetic you can redo. Prices are checked daily — last verified January 1, 1970. Here is exactly how we pick.
Two mowers, two batteries each, the same 80-minute claim on both boxes. It looks like a coin toss until you ask where the second pack lives while you are mowing, and then it stops being close.
The short answer
Where the second pack lives
Two things fall out of that. Kobalt carries 160Wh more onto the lawn, and Ryobi is about 25% more frugal per minute. Ryobi buys its 80 minutes with efficiency and a trip back to the machine; Kobalt buys them with capacity.
#ad Check the Kobalt 80V Max 21" Self-Propelled (dual-port) price on Amazon — how we're funded.
The published sheets
| Spec | Ryobi RY40HPLM01B | Kobalt 80V dual bay |
|---|---|---|
| Deck | 21 in | 21 in, steel |
| Batteries in the kit | 2 x 40V 6.0Ah | 2 x 80V 4.0Ah |
| Energy | 480Wh owned, 240Wh live | 640Wh installed |
| Runtime claim | Up to 80 min | Up to 80 min |
| Watt-hours per minute | 6.0 | 8.0 |
| Acreage rating | Not published | Up to 1 acre |
| Drive | Variable-speed RWD self-propel | Self-propelled RWD, 7 speeds |
| Cut height | Not published | Not published |
| Weight | Not published | Not published |
| Recharge | Not published | Approx. 60-90 min |
| Where it sells | Multiple retailers | Lowe's |
From the Ryobi RY40HPLM01B and Kobalt dual-bay listings, checked 3 September 2026.
This is the least-documented pairing in our registry. Neither publishes a weight or a cut-height range, and neither states a warranty on the page we cite. If specification transparency is what you shop on, both of these lose to Greenworks — the audit is in how to read a spec sheet.
What each buys you afterwards
Ryobi 40V is the broader platform of the two in our registry. The same pack that runs the mower runs a 730 CFM blower published at 57 dB and a 17 inch trimmer published at 67 minutes. That is three tool classes on one battery.
| Tool class | Ryobi 40V | Kobalt 80V |
|---|---|---|
| Walk-behind mower | Yes | Yes |
| Handheld blower | Yes, 730 CFM at 57 dB published | Outside our registry |
| String trimmer | Yes, 15-17 in adjustable, 67 min | Outside our registry |
| Retail availability | Multiple retailers | Lowe's only |
| Other line to avoid confusing it with | 18V ONE+ | None in our registry |
"Outside our registry" means we hold no cited manufacturer spec sheet for a Kobalt 80V tool in that class, not that none exists.
Single-retailer supply is the quiet risk on the Kobalt side. It is not a fault in the machine and Lowe's is not going anywhere, but a battery family you can only restock from one chain is a narrower commitment than one you can buy anywhere.
#ad Check the Ryobi 40V HP Brushless 21" Self-Propelled price on Amazon — how we're funded.
Who should buy which
Kobalt if
- Your lot is near an acre and you want it finished without a pack swap
- The mower is the purchase and the rest of the yard is already handled
- You want seven published drive speeds
Ryobi if
- There will be a blower and a trimmer after this
- Quiet matters — the 57 dB Whisper blower is on this platform
- You would rather not tie a decade of packs to one retailer
- Your lawn finishes inside 40 minutes, in which case the swap never happens
What we cannot tell you
Whether the Kobalt bays discharge in parallel or sequence is unstated, so we do not claim it. Neither brand publishes a weight, so we cannot tell you which is harder to push uphill. And neither states a warranty term on the pages we cite, which on a purchase of this size is a genuine gap.
The arithmetic that is available: 640Wh installed against 480Wh owned, 8.0Wh per minute against 6.0, one published acre against no acreage figure, and one retailer against many.
The products discussed
Specs are the manufacturer's own and linked to the page they came from. Prices come from a live daily check; where we have no verified price we say so rather than print a stale one.
Kobalt 80V Max 21" Self-Propelled (dual-port)
Kobalt · Kobalt 80V Max · Our score 8.4/10
#ad No verified live price right now, so we show none rather than a stale one. How we're funded.
Two 4Ah bays, 80 published minutes and an acre rating -- the most runtime per purchase of any 80V walk-behind here.
Published specs
| Deck | 21 in, steel |
|---|---|
| Motor | Brushless |
| Batteries included | 2 x 80V 4.0Ah (dual port) |
| Runtime claim | Up to 80 min |
| Rated for | Up to 1 acre |
| Drive | Self-propelled RWD, 7 speed settings |
| Recharge | Approx. 60-90 min |
Source: Kobalt 80-Volt 21-in Self-propelled Battery Mower (2 batteries), lowes.com
80V x 4.0Ah = 320Wh per pack; two bays = 640Wh installed. Kobalt's listing does not state whether the two ports discharge simultaneously or in sequence, so we do not claim either -- what is verifiable is that 640Wh is on the machine when you start.
What the numbers favor
- 640Wh installed across two bays, the most of any walk-behind on this page
- Rated to 1 acre, twice the Greenworks 80V flagship's half-acre rating
- Seven published speed settings on the self-propel drive
- All Kobalt 80V packs are cross-compatible across the 80V outdoor line
What they don't
- Sold through Lowe's only, so availability and price track one retailer
- The listing does not publish weight, cut-height range or a noise figure
- Kobalt's 80V outdoor range is narrower than EGO's or Ryobi's
you want a platform rather than a mower. Kobalt is a single-retailer house brand -- fine for the tool, thinner as a decade-long ecosystem bet.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Ryobi 40V HP Brushless 21" Self-Propelled
Ryobi · Ryobi 40V · Our score 8.6/10
#ad No verified live price right now, so we show none rather than a stale one. How we're funded.
Two 6Ah packs and the longest published runtime claim on this page, on the platform with the cheapest route to a fourth and fifth tool.
Published specs
| Model | RY40HPLM01B |
|---|---|
| Deck | 21 in |
| Motor | Brushless, 40V HP |
| Batteries included (kit) | 2 x 40V 6.0Ah |
| Drive | Variable-speed rear-wheel self-propel |
| Runtime claim | Up to 80 min on 2 x 6Ah |
Source: 40V HP Brushless 21" Self-Propelled Mower, ryobitools.com
40V x 6.0Ah = 240Wh per pack; the kit ships two, so 480Wh total -- but only 240Wh is available at any moment, because the mower draws one pack at a time.
What the numbers favor
- 480Wh across two packs, the most total energy in any kit here
- Two packs means you swap and keep mowing instead of waiting on a charger
- Ryobi's 40V range is the broadest consumer battery line of the three platforms
What they don't
- Only one 240Wh pack is live at a time -- the 480Wh is sequential, not simultaneous
- Ryobi does not publish a cut-height range or weight on the product page, so both are unknown to us
you own nothing on Ryobi yet and expect to buy heavy tools later. 40V is the lowest voltage of the three platforms, and the ceiling shows on chainsaws and riding gear.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Where to buy the tools on this page
Every link below is an Amazon affiliate link. We show no price we have not verified today, so where there is no live figure the link says "check price" and takes you to the listing to read it there.
Best two-bay runtime
Kobalt 80V Max 21" Self-Propelled (dual-port)
Kobalt · Kobalt 80V Max
Best for a household already on Ryobi
Ryobi 40V HP Brushless 21" Self-Propelled
Ryobi · Ryobi 40V
#ad As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. How we're funded.
Common questions
Is Ryobi 40V or Kobalt 80V better?
Do both mowers really run 80 minutes?
Which carries more energy?
Does Kobalt draw both batteries at once?
Which is the safer platform bet?
Which is rated for a bigger lawn?
Sources
Read next
- Battery Platforms
Pick the system once and the next four tools are decided for you. Start here.
- EGO 56V vs Kobalt 80V Max: more energy now, or more platform later
640Wh installed against 420Wh, and a one-retailer platform against a nine-tool one.
- Greenworks 80V vs Kobalt 80V: same voltage, different bets
Same 80V sticker, double the installed energy on one of them. The comparison is about packs, not volts.
- The Ryobi 40V platform, tool by tool
One outdoor family, two-pack kits, a 57 dB blower -- and the thinnest published specs.
- How many batteries do you actually need?
Lawn size to watt-hours to pack count, plus the sequential-versus-simultaneous distinction.
- Best self-propelled battery lawn mower
Four self-propelled machines on installed watt-hours, drive speed and acreage rating.