Does the 7.5Ah batter actually provide 50% longer run time than the 5Ah batter?

  • 2
  • Question
  • Updated 7 months ago
  • Answered
Photo of Dracunculus

Dracunculus

  • 90 Points 75 badge 2x thumb

Posted 7 months ago

  • 2
Photo of Prairiedog

Prairiedog

  • 3,542 Points 3k badge 2x thumb
we have both and use both to mow the same areas, and yes, I would say it is about twice as long run time.
Photo of Oregon Mike

Oregon Mike, Champion

  • 37,228 Points 20k badge 2x thumb
Prariedog, twice as long, or half again as long? Say, 45 minutes on 5ah battery, so 90 minutes on 7.5 or more like 1 hr on 7.5? I know I can get close to 1 hr out of my 5ah battery if I ignore the first red flash I see on the mower indicating low battery. I can usually squeeze another 10 minutes of mowing after I see the first red light.
(Edited)
Photo of Prairiedog

Prairiedog

  • 3,542 Points 3k badge 2x thumb
I'm not exactly sure. We base it on what we get mowed on which battery. Using the SP heavily, cause we have hills, a 7.5 will do our big country front, side and back yards, and some of our paths or rough. The 5 only does one yard and the sides for sure. Sometimes we can squeak out a bit of the back if I stop using the SP. I also ignore the first solid red. Mostly cause I try to get mowed closer back to the barn so I don't have to walk so far to make the switch, lol. But because it can take a few hours to do everything, we bought a second so we can work simultaneously. With two of us working we get it done in about an hour, using the two 7.5s.
(Edited)
Photo of Jacob

Jacob

  • 62,158 Points 50k badge 2x thumb
Take the runtime of the 5 ah. And multipy that by 1.5. not 2
Photo of Prairiedog

Prairiedog

  • 3,542 Points 3k badge 2x thumb
I wasn't saying I couldn't do the math, I was just saying, Isn't run time a sorta imaginary measure? It all depends on how you use it, like running in SP or not, and what demands you are making while you are mowing, doesn't it? Mowing thick patches of weedy rough uphill using SP full time will tax the battery faster than trimming a half inch of soft bluegrass in manual push mode. I don't think I ever squeaked an hour out my 5 ampers like Mike does. And I don't ask the 5s to play in the woods anymore, but they sure can do the lawn jobs when I need to call on them. I was saying my 7s do twice the work as the 5s under the same conditions, so I would say the 7.5s, the way we use them, last twice as long.
(Edited)
Photo of szwoopp

szwoopp, Champion

  • 69,072 Points 50k badge 2x thumb
Understood that use/conditions changes run time.  But the OP question and Jacob's response are only saying that under identical conditions a 7.5 battery will run 50% longer or 1.5 times the 5.0 battery.
That is what the Ah is intended to measure and in answer to the OP question it is an accurate number.
(Edited)
Photo of Prairiedog

Prairiedog

  • 3,542 Points 3k badge 2x thumb
Yeah, I get that, but treating the question as if the OP was asking a simple, obvious math problem does not answer what I assumed was the intent of their post. When discussing run time, folks really want to know how much they can get "done" when the tools are running, not just how long they run for, and is there a substantial difference between the two batts? Not just the ratio between the two. They want to know, "will I be able to mow everything on one charge?" I was only trying to give real world experience, which in my case is, despite it only being 1.5x larger, "I" get "2x" as much "done," despite the math implying I should only get 50% more. I was trying to assure them the bigger one is worth it. Not sure why I'm getting schooled here? My guess is the OP already knows that 5 x 1.5 equals 7.5 as well, by the way they phrased the question. I was simply answering, "yes, and it could be more than the simple math implies."
(Edited)
Photo of szwoopp

szwoopp, Champion

  • 69,072 Points 50k badge 2x thumb
I like answering from both angles.  When I first bought my mower and came on this board that simple question was a legitimate one for me because I had no clue what Ah was measuring.  I needed both answers and thus I like giving both.
Photo of Dracunculus

Dracunculus

  • 90 Points 75 badge 2x thumb
Thanks for the responses. I was assuming "all else being equal" when I asked my question - not comparing different running conditions. And yes, the numbers imply 150% runtime but, numbers aren't necessarily real-world. Hence the question.