Directly replacing NiMh cells with Li-Ion cells - bad idea ?

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • stj
    Great Sage 齊天大聖
    • Dec 2009
    • 30965
    • Albion

    #21
    Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

    laptop pulls? those are usually only rated for 2.8A continuous load before bad shit ensues!!

    Comment

    • Dannyx
      CertifiedAxhole
      • Aug 2016
      • 3912
      • Romania

      #22
      Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

      No, they were bought brand new by me personally from a local shop, though I believe some packs may use those indeed...
      Wattevah...

      Comment

      • redwire
        Badcaps Legend
        • Dec 2010
        • 3902
        • Canada

        #23
        Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

        BMS boards are only a few dollars. Look at 4S 30A 14.8V li-ion battery BMS using S-8254AA protection IC. They have pack over-current and over-discharge, over-charge protection.

        Comment

        • stj
          Great Sage 齊天大聖
          • Dec 2009
          • 30965
          • Albion

          #24
          Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

          i suspect this is the type of repair shop that would re-use the solder if they could.

          Comment

          • eccerr0r
            Solder Sloth
            • Nov 2012
            • 8690
            • USA

            #25
            Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

            Alas, even having a BMS board that handles 30A, it doesn't help if the cells themselves can't handle 30A.

            Incidentally, if people saw the few posts I made about one of my HTs that someone swapped 7 NiCd cells for 3 Li-ion with NO protection circuitry... surprisingly the radio still works...and I am still thinking about how to best add protection circuitry as currently there's no good way of charging the pack, either.

            Comment

            • Dannyx
              CertifiedAxhole
              • Aug 2016
              • 3912
              • Romania

              #26
              Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

              Originally posted by stj
              i suspect this is the type of repair shop that would re-use the solder if they could.
              Correct...not so much the shop itself (it certainly could afford A LOT more - even a superficial glance at its budget tells me this !), but this particular chap who I suppose doesn't have the guts to ask the boss for better/new stuff so he makes due with what he has... Remember: used capacitors in clients' stuff - can't get over that ! >_>

              Not sure how much a motor on one of those handheld vacs draws at startup TBH, though I remember a friend of mine had one whose batteries died and he tried hard-wiring it to a 5a power brick and it entered protection upon startup. The only way he was able to get it going was to use a PC power supply. I was thinking of designing an inrush current limiter for him to hopefully keep the load down at least until after the motor has spun up to keep the brick from turning off, but now that I think back, I think the RUN current itself was greater than 5a anyway, so it was no good. I'm surprised at how much current a small motor draws ! :|
              Wattevah...

              Comment

              • stj
                Great Sage 齊天大聖
                • Dec 2009
                • 30965
                • Albion

                #27
                Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                until a motor is moving, it's a dead short.
                and it probably needs the current to start - so inrush limiting has to be done carefully.

                Comment

                • Dannyx
                  CertifiedAxhole
                  • Aug 2016
                  • 3912
                  • Romania

                  #28
                  Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                  I'm still keeping an eye on my colleague who is still working on this vac. Curious to see how it ends up Today he fiddled with it some more and the vac itself actually works, but doesn't charge, at least not properly: the LED on the dock is not coming on, though it does push some voltage into an otherwise low battery, for he tried draining the batteries with the vac itself and then charging it on the dock and it appeared to work...how well is debatable and could very well shorten the lifespan of the batteries...

                  I'm also laughing my ass off because this PERFECTLY reminded me of THIS episode from Dexter's laboratory - I won't spoil it for you, so feel free to watch
                  Wattevah...

                  Comment

                  • stj
                    Great Sage 齊天大聖
                    • Dec 2009
                    • 30965
                    • Albion

                    #29
                    Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                    so is the idiot still using lithiums in it?

                    Comment

                    • Dannyx
                      CertifiedAxhole
                      • Aug 2016
                      • 3912
                      • Romania

                      #30
                      Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                      'fraid so...he even cracked open another laptop pack to score himself some cells to try out Something's gonna pop in his face one day
                      Wattevah...

                      Comment

                      • stj
                        Great Sage 齊天大聖
                        • Dec 2009
                        • 30965
                        • Albion

                        #31
                        Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                        show him this!!!
                        https://www.youtube.com/watch?v=WdDi1haA71Q

                        Comment

                        • budm
                          Badcaps Legend
                          • Feb 2010
                          • 40746
                          • USA

                          #32
                          Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                          He will burn down the house while charging the batteries when he is not at home.
                          Never stop learning
                          Basic LCD TV and Monitor troubleshooting guides.
                          http://www.badcaps.net/forum/showthr...956#post305956

                          Voltage Regulator (LDO) testing:
                          http://www.badcaps.net/forum/showthr...999#post300999

                          Inverter testing using old CFL:
                          http://www.badcaps.net/forum/showthr...er+testing+cfl

                          Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                          http://s807.photobucket.com/user/budm/library/

                          TV Factory reset codes listing:
                          http://www.badcaps.net/forum/showthread.php?t=24809

                          Comment

                          • eccerr0r
                            Solder Sloth
                            • Nov 2012
                            • 8690
                            • USA

                            #33
                            Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                            I've charged my Kenwood's batteries overnight once by mistake... lucky lucky it didn't blow up as there's no protection circuitry...

                            Comment

                            • stj
                              Great Sage 齊天大聖
                              • Dec 2009
                              • 30965
                              • Albion

                              #34
                              Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                              then add some - you get 10 for a $ now!!!

                              Comment

                              • Dannyx
                                CertifiedAxhole
                                • Aug 2016
                                • 3912
                                • Romania

                                #35
                                Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                                Originally posted by budm
                                He will burn down the house while charging the batteries when he is not at home.
                                Worse, since it's not HIS vacuum
                                Wattevah...

                                Comment

                                • eccerr0r
                                  Solder Sloth
                                  • Nov 2012
                                  • 8690
                                  • USA

                                  #36
                                  Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                                  Originally posted by stj
                                  then add some - you get 10 for a $ now!!!
                                  But aren't people supposed to like living on the edge?

                                  Comment

                                  • stj
                                    Great Sage 齊天大聖
                                    • Dec 2009
                                    • 30965
                                    • Albion

                                    #37
                                    Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                                    not like that.

                                    i was testing some used 18650's yesterday and charging them at 1Ah,
                                    one got so hot i pulled it out and threw it into the garden!!!!

                                    Comment

                                    • Dannyx
                                      CertifiedAxhole
                                      • Aug 2016
                                      • 3912
                                      • Romania

                                      #38
                                      Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                                      At least you have a garden
                                      Wattevah...

                                      Comment

                                      • sam_sam_sam
                                        Badcaps Legend
                                        • Jul 2011
                                        • 6030
                                        • USA

                                        #39
                                        Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                                        That is why I charge and discharge these batteries before I use them

                                        I have had some that just do not have the load capacity that they claim to be

                                        I will not use them if they get warm when charging them at 2 amp or at 1 amp

                                        If when discharging then a 2 amp and get warm or at 1 amp I will not use them

                                        I use caution when using Chinese made batteries because either the quality of the cells or that the quality control is very poor ( meaning that no two cells are the same )

                                        That video was some real serious shit
                                        Last edited by sam_sam_sam; 02-05-2019, 04:18 PM.

                                        Comment

                                        • sam_sam_sam
                                          Badcaps Legend
                                          • Jul 2011
                                          • 6030
                                          • USA

                                          #40
                                          Re: Directly replacing NiMh cells with Li-Ion cells - bad idea ?

                                          Originally posted by stj
                                          not like that.

                                          i was testing some used 18650's yesterday and charging them at 1Ah,
                                          one got so hot i pulled it out and threw it into the garden!!!!
                                          What brand of batteries were they

                                          Comment

                                          Related Topics

                                          Collapse

                                          • AlexVG
                                            Replacing the WiFi module on a vacuum cleaner iROBOT i7
                                            by AlexVG
                                            Hi,
                                            I have had an iROBOT i7 with a camera error (error 68) version REV M, year 2018.

                                            I bought a liquid damaged Mainboard with WiFi module, from the same vacuum cleaner, but a different year and a different version (REV G).
                                            (This board does not respond, only the LEDs light up in a circle.
                                            The liquid damage is catastrophic and restoration is impractical).
                                            (I bought this board to get the WiFi module and camera).

                                            The boards are completely different in the installation of elements, even the connector for the WiFi module is different.

                                            If...
                                            10-22-2024, 07:20 AM
                                          • Chaks
                                            The ups takes 3 x 18650 cells in Parallel - Can I extend to 6 x 18650 safely?
                                            by Chaks
                                            I need help to extend the runtime of the ups board (see attached image).
                                            This is ups board for a CM4 which has 3 18650 cells in parallel. Can I extend the 3 cells to 6 cells for a longer runtime? by soldering a wire to each of the battery terminal and connecting it to a separate battery case with 6 cells.
                                            Thanks and kind regards,
                                            chaksindia...
                                            01-21-2025, 11:39 AM
                                          • flat-earther
                                            Hoover FM216LI cordless vacuum refuses to charge
                                            by flat-earther
                                            I have a Hoover FM216LI cordless vacuum which isn't charging its internal battery.

                                            I opened up the unit, and it has 6x Samsung ICR18650-22P cells connected in series.
                                            5 cells were at about 3.3-3.1V. one was at 2.4V, so I assumed this cell was bad that's why the vacuum wasn't charging so I replaced it with another 18650, but after that the problem still persists, the vacuum turns on a bit and then cuts out since the batteries are empty.

                                            So I think the over discharged battery wasn't the culprit, it was a symptom of the unit not being able to charge its batteries....
                                            06-06-2025, 03:14 AM
                                          • Petr0x
                                            Bosch 12V and 18V chargers modification
                                            by Petr0x
                                            Hi, I would like to share with you small modification to your Bosch tool 12V and 18V chargers.

                                            You can use it for almost all Bosch chargers what I have seen, for example part numbers GAL 18V-20, GAL 18V-40, GAL 1880, GAL 18V-160, AL 1820, AL1115CV, AL1130CV.

                                            Bosch (today also other brands using the same system like Wurth, Fein) does not care if you destroy your batteries, because they can sell you new ones. So the marketing is telling you only about speed of the charging, so you will not wait for your batteries to charge too long. Me as a customer want the tools and batteries...
                                            05-24-2024, 01:00 PM
                                          • sam_sam_sam
                                            ZD-915 vacuum pump motor mount service alert
                                            by sam_sam_sam
                                            If you have this Desoldering Gun Station there is something you should be aware of the two screws that hold the motor to mounting for pump can come loose and make raddling noise

                                            One note this unit has been repaired already once because of switching power supply regulator ic chip failure
                                            Now this with the vacuum motor mounting issue yes I give this Desoldering station a very hard work out and use about every weekend to do some type of project

                                            The fix is taking the vacuum pump assembly out and take the metal cover off and you will see the two screws on it
                                            ...
                                            09-19-2021, 02:15 AM
                                          • Loading...
                                          • No more items.
                                          Working...