I have a 2.5Ah 80V battery from Kobalt for a weedwacker and am looking to get a mower. I see some good used Kobalt 80V mowers but it's not always clear if it was originally sold with a 2.5Ah battery, or a 4Ah battery or what. Are these mowers fit to specific capacity batteries?

On Lowe's website there are Kobalt 80V mowers sold with different amp-hour batteries:

The 4Ah and 5Ah 80V battery looks the same as my 2.5Ah 80V battery but I'm not sure if that capacity difference would matter somehow. The difference in price for those pages further confuses matters to me.

  • 2
    The amp-hour rating of a battery is not really a factor in compatibility, so long as it's not vastly different from the original battery. If one battery's amp-hour rating is within a factor of 2 of the alternative battery then there should be no problem (other than operating duration), provided the voltages are (nearly) identical.
    – Hot Licks
    Jul 20, 2022 at 0:09
  • 1
    Car battery $100, DC-DC converter (80 V output) $30 = 20 Amp hours
    – Traveler
    Jul 20, 2022 at 4:19
  • 1
    I have more than a dozen DeWALT 20v batteries ranging from 2 to 8Ah. They will all work in any of my DeWALT tools. I get more run time from the higher Ah rated batteries. I'm pretty sure it'll be the same for Kobalt brand tools and, actually for <insert brand name here> tools.
    – FreeMan
    Jul 20, 2022 at 11:41
  • 1
    @FreeMan Hand tools are a different ballgame compared to a lawnmower. My toolset is Ridgid and most tools feel about the same regardless of Ah rating. The one handtool where I can notice a difference is in their Jobsite Blower. The engine revs audibly higher with a 4 Ah as opposed to the 2 Ah; the 9 Ah sounds the same as the 4 Ah. Read protoolreviews.com/battery-amp-hours-affect-power for more info.
    – MonkeyZeus
    Jul 20, 2022 at 11:48
  • 1
    TBF, @MonkeyZeus, the 8Ah battery is their "XR" or "Plus" (or something) and came with the 7-1/4" circular saw. The saw will run on any of the smaller batteries, but not nearly as well. Even no-load, it doesn't sound like it spins up as quickly. Other tools do sound like the run a little faster with that 8Ah battery, but it's heavy enough I really don't use it except for cutting (circular, jig, sometimes grinder).
    – FreeMan
    Jul 20, 2022 at 12:00

1 Answer 1


The ampere-hour rating for a battery is a rough approximation of run time, also approximately equivalent to fuel capacity. I was temporarily confused by the disparity in prices, but then noted that the two more expensive units provide two batteries and operate on two batteries, while the lowest price one uses a single battery.

This means the $600 unit has 5 Ah capacity, the $750 unit has 8 Ah capacity. The lowest price one appears to be a better deal in that it's a 5 Ah battery priced one hundred dollars less than the two battery version.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.