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Running a lead acid battery lawn mower on lithium ion

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  • Running a lead acid battery lawn mower on lithium ion

    Firstly forgive me as this question does not involve solar panels. I joined this forum as I have panels and intend to use them more. This question is specifically about batteries.
    I have an enviromower lawn mower at uses 2x12 volt 10 ah batteries in series so a 24 volt machine. I had a brain wave of using a 24 volt 10ah lithium ion instead of lead acid. The price was comparable and the unit came with its own charger so I could not see any issues.
    It seemed to work fine for about 5 minutes and then smoke and a heavy electrical burning smell came from the battery. The 18650 batteries that make up the battery unit seemed fine but the circuit board had some burnt components that look like transistors. I assumed the charge circuitry was independent and managed to recharge the batteries successfully. Now I want to use them again in the lawn mower. I'm not sure what circuitry has blown. Maybe it was protection to stop over drawing the battery or thermal protection I'm not sure.
    Can anyone suggest what I need to do to use these batteries? Can I even use these batteries in the mower? The battery was brand new so it may have been a quality issue in the first place.
    I've attached a photograph of the burnt battery for your information and here is a link to the original battery I purchasedIMG_20191023_152221.jpg
    Attached Files

  • #2
    Well the batteries are OK, but the BMS is toasted. Will the vendor replace it ?

    My guess as to what happened, the motor drive circuit, generated some electrical noise that upset the circuit in the battery and fried it. Motors generate electrical noise and voltage spikes and that's what fried the board.
    Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister

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    • #3
      Originally posted by Mike90250 View Post
      Well the batteries are OK, but the BMS is toasted. Will the vendor replace it ?

      My guess as to what happened, the motor drive circuit, generated some electrical noise that upset the circuit in the battery and fried it. Motors generate electrical noise and voltage spikes and that's what fried the board.
      Yes brush motors do things like that. I have seen (very short) 300V spikes from my
      12V starter motor. Bruce Roe

      Comment


      • #4
        Originally posted by Mike90250 View Post
        Well the batteries are OK, but the BMS is toasted. Will the vendor replace it ?

        My guess as to what happened, the motor drive circuit, generated some electrical noise that upset the circuit in the battery and fried it. Motors generate electrical noise and voltage spikes and that's what fried the board.
        Ok thanks, so what can I do? Do I need the BMS (presumably the stands for battery management system)? Can I bypass the BMS and plug the batteries directly into the mower? Maybe I could put some capacitors across to smooth the current? Can I buy an aftermarket BMS that will do the trick? My other option is going back to lead acid batteries and storing these li-Ions on a shelf some place.

        Replacing the battery doesn't seem to be an option as I expect the same thing will happen. Due to the difference in freight charges (from China to New Zealand and here to China) it's not worth getting the warranty replacement...

        Thanks in advance.

        Comment


        • #5
          I am not an expert in gardening but I know how difficult it is to maintain a nice garden. I had a type of grass that was too thick for my lawn and because of that my lawnmower broke. I went online and found out that it broke because it was not strong enough to cut the grass. I then bought another one from growgarden dot com and have been using it since. I suggest you contact them if you have issues with your equipment because they will surely be able to help you with that.

          Please don't include links to advertising of equipment in your post.
          Last edited by SunEagle; 10-05-2021, 08:29 AM. Reason: removed link and added warning

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          • #6
            That spammer is not going to read your warning or even care what it says.

            Why even allow the name of the company to remain in his post? He 100% came here to spam and place commercial links about lawnmowers. Just delete the post and ban him.
            Dave W. Gilbert AZ
            6.63kW grid-tie owner

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            • #7
              Lithium batteries do not outperform lead acid batteries in certain circumstances. Lithium cells with a higher C rate will be able do the job, but may just be easier to replace to a lead acid battery.

              Usually the BMS limits the batteries to perform within specs and you don’t want to exceed that. I’ve looked at lithium ion cells that are supposed to discharge up to 6C, which I thought were 18650s. Maybe that’s just the casing size.

              I don’t know if that pack has a BMD, but looking at it I don’t think so. So, I with no BMS there is no way for the battery to shut down. So IMO, it’s not a quality issue. There’s times you don’t want a BMS, like perhaps when the battery powers a wheel chair and you don’t want he BMS shutting down in the middle of a crosswalk when accelerating to miss a car.

              There’s another thread on a different forum of someone starting todo an Lithium battery swap on an electric mower, but he never found cells rated for it.

              Comment


              • #8
                Originally posted by azdave View Post
                That spammer is not going to read your warning or even care what it says.

                Why even allow the name of the company to remain in his post? He 100% came here to spam and place commercial links about lawnmowers. Just delete the post and ban him.
                Maybe you are correct. But if I banned everyone that I thought was a spammer there would be a lot less members on the forum.

                I believe in giving someone a chance first to prove themselves and see if they can become a good source of info before I jump to the conclusion that they just want to cause harm. But then again I have been called a softy before.

                Comment


                • #9
                  It was actually, an answer ( but not a really useful one) to a question. I too would have munged the link, and let the text stand
                  Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
                  || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
                  || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

                  solar: http://tinyurl.com/LMR-Solar
                  gen: http://tinyurl.com/LMR-Lister

                  Comment

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