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Likorall 200 Ceiling Hoist - Lithium battery conversion

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    Likorall 200 Ceiling Hoist - Lithium battery conversion

    I am considering a Lithium battery conversion for our Likorall 200 Ceiling Hoist as it is about at the end of its current set of batteries but I was wondering if there are any considerations I need to think about such as voltage regulation.

    It is used for powered transfers of a disabled person from chair to bed a few times a day in a private household. It is our own property and is 6 years old.

    ===

    It is fitted with a pair of Yuasa 12V 2.4Ah AGM batteries in series for a 24V system. The batteries are the long thin type with the terminals on one end connected via 4.8mm spade connectors.

    The charger in the UK 3-pin socket is a Pb battery charger rated at 100-240V, 50-60Hz AC outputting 24V DC at up to 0.5A with model number FW7218M/24. It ends in a standard 5525 barrel jack.

    The free-floating hoist has a handset with two buttons and an LED indicator on a curly cable that docks in a cradle. When the handset is docked the hoist is electronically prevented from operating while the batteries are on charge.

    The Pb charger has an LED indicator showing charging/charged. The handset has a bright yellow LED to show it is connected to the charger.

    It spends almost all of its time connected to the charger for battery management so any Li cells would have to be of a type that tolerate being fully charged very well.

    When the handset is removed from the charger the indicator LED dims and goes green to presumably show "good charge". It will either change to yellow or start blinking to indicate "low charge" but we have never used the hoist that much in one day to trigger that condition.

    I suspect that if I was to change the wall charger to one which supported Lithium cells (that could be connected to the charger long term) and replace the pair of Yuasa cells with a single Lithium pack of around 24V with the appropriate connectors we would be good to go apart from voltage regulation.

    Would I need to consider the voltage range of a 24V Pb sytem between 100% down to about 50% and make sure the Lithium pack was operating at the same sort of voltage? I have not examined the ceiling hoist to see if there is any regulation circuit on its main board yet but I could certainly do so.

    Before I start drawing up a shopping list, what else should I be thinking about? So far I know I need a Lithium charger and a suitable battery around 24V, probably LiFePO4.

    Thank you.

    #2
    Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

    you cant constant charge lithiums.
    not even at low current.

    Comment


      #3
      Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

      I assumed some sort of BMS in conjunction with the charger would take care of that? How is it handled with consumer devices that have Lithium batteries then?

      Comment


        #4
        Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

        They are "smart" chargers so you'll need to locate one of these too. Ideally you need to locate a charger that was meant to be continually connected but only charge when it needs to charge - and all portions of the original lead charging circuit need to be modified to deal with lithium ion as well especially if they split it poorly for lithium ion. Sometimes it's nontrivial to modify -- unless if you don't care about things like charge status etc.
        Last edited by eccerr0r; 03-05-2023, 11:47 AM.

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          #5
          Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

          I had assumed I would have to completely replace the old charger completely. It is just a main socket external supply with some Pb-specific controls anyway. The equivalent Lithium charger/BCM configured for 24V would be fine.

          The lead AGM batteries are internal to the hoist body and there would be plenty of room for a Lithium pack in their space. I could even change the connectors to something more suitable for hobby Lithium packs.

          It seems from the datasheet that the AGM batteries have a voltage range of 12.25V at 50% to 13.00V at 100% so the pair range between 24.5V to 26V.

          Comment


            #6
            Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

            Originally posted by DanielCoffey View Post
            I had assumed I would have to completely replace the old charger completely. It is just a main socket external supply with some Pb-specific controls anyway. The equivalent Lithium charger/BCM configured for 24V would be fine.

            The lead AGM batteries are internal to the hoist body and there would be plenty of room for a Lithium pack in their space. I could even change the connectors to something more suitable for hobby Lithium packs.

            It seems from the datasheet that the AGM batteries have a voltage range of 12.25V at 50% to 13.00V at 100% so the pair range between 24.5V to 26V.
            Not exactly correct 13.4 to 13.8 which is more like 26.6 to 27.6 volts

            Not necessarily it depends on what type of lithium batteries if you use Life-po-4

            ( when fully charged voltage is 3.6 ) (but when battery are discharged 2.5 volts but the roll of voltage is a little higher than this ) ( if you try to go with regular lithium when fully charged voltage 4.2 volts and discharged voltage is around 3.4 which might work depending on the charge on the device )

            with the right BMS board and the charger for the battery pack is the right voltage for this type of battery you should be able to do 8 X3.3 = 25.9 ( with no power connected to it ) 7 X 3.6 = 25.8 when charging at the maximum voltage

            Now if you use regular lithium batteries that 4.2 fully charged 6 X 4.2 = 25.6 fully charged and discharged around 19.0 or so

            You will have to know how the battery charger on this device works before you can decide whether or not you could use lithium ion batteries or not low state of charge / high state of charge from the device and see what type of setup would work the best this will be very important to know for this to work correctly or not

            I have a UPS battery back up that I did this on the only issue I had is if you let the UPS drain completely out it would not recharge by it self because of the BMS protection board was the type that did not reset it self automatically you had to put it on a charge external from the UPS battery backup but once you reset it then it would recharge correctly again
            Last edited by sam_sam_sam; 03-06-2023, 06:59 PM.
            9 PC LCD Monitor
            6 LCD Flat Screen TV
            30 Desk Top Switching Power Supply
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            6 18v Lithium Battery Power Boards for Tool Battery Packs
            1 XBox 360 Switching Power Supply and M Board
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            6 De-soldering Station Switching Power Supply 1 Power Supply
            1 Dell Mother Board
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            1 HP Printer Supply & Control Board * lighting finished it *


            These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

            1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
            2 Hem Saw Computer Stack Board

            All of these had CAPs POOF
            All of the mosfet that are taken out by bad caps

            Comment


              #7
              Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

              Thank you for the reply. I will test the current AGM battery voltage when it is freshly charged as I take the handset off the cradle as well as when it has had a time to settle to rest.

              I would appreciate knowing whether LiFePO4 or Li-Ion are able to be maintained at a full state of charge since this hoist tends to be docked most of the time for readiness.

              I presume there would be an option in either the Lithium charger or the BMS to set a user defined maximum voltage so that I could choose to hold at a lower state of charge? Given the low usage of the hoist each day I would be prepared to budget for a larger battery capacity but not charge to 100%.

              Comment


                #8
                Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                A couple of 12V 2.4Ah AGM’s in that seems a bit smallish for my taste. How long did this battery last in there? My bet is that the constant voltage charger is cooking the batteries. Those Li-Ion type batteries don’t like to be constantly plugged in. While it does work for quite a while, soon enough they bulge and could create a fire hazard.

                I think in your case your better off putting in a different size AGM’s check the charging voltage on the charger to not cook the batteries all the time and periodically water the AGMs a bit and if you got, put them on a desulfator at the same time. I run many AGM”s this way and batteries last from 5 to 8 years no problem.

                SLA’s are so easy to charge and they do last quite a while, if you take care of them. For me I couldn’t sleep well knowing a Li-Ion is plugged in 24/7/365 next to a disabled person. I had a Walkie-Talkie with a Li-Ion in my car always plugged in and it charged the battery.each time I drove the car. After a year the batteries were bulging. While these Li-Ion’s are good, they aren’t that good for what you are trying to do, specifically if the device sits on a charger all the time. Anyway, that’s my take on it.

                Comment


                  #9
                  Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                  The original AGMs supplied by the manufacturer struggled after three years and were very expensive to replace with the same brand since they were labelled exlusively for this application and priced accordingly.

                  I replaced them with Yuasa medical grade AGMs that have just passed three years and are just beginning to struggle when lifting hence why I am considering my Lithium options rather than simply replacing the AGMs again.

                  There is definitely some intelligence build into the Pb charger as it has a "yellow - still charging" and "green - full" indicator but I suspect it keeps them on a very low trickle all the time.

                  There are two things of note - no more room inside the unit for bigger AGMs and due to extremely short cabling the manufacturer chose to mount the existing AGMs upside down in the unit! Yes, I know AGMs can be operated upside down but they all advise not charging in this oirientation. When challenged about this, the manufacturer stated that the charging current was so slow that it was not an issue.

                  There simply isn't room for a bigger AGM but if I did replace them again with new AGMs I would certainly alter the cables to allow correct mounting although this would also require preventing a short from the terminals into the aluminium housing they are in.

                  Comment


                    #10
                    Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                    I’d take the lid off the batteries and put 2ml of distilled water, or used battery acid from a car battery in each cell. Reseal the lid and desulfate the battery. That should keep it going for a while. I water my SLA’s every 2-3 years, desulfate them afterwards and put ‘em back in. I do so until a cell fails. Since I have so many of them (mostly 12V 7Ah) and spend a day or two fixing old batteries, I still save tons of money.

                    Comment


                      #11
                      Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                      The batteries are discharged at quite high current during a lift, 12A which is hard on them and why I think they have a short life. They are on the small side. You would have to use high-discharge rate AGM, like for UPS.
                      It could be more than most lithium cells can supply, and for longer time so they'd heat up. I wonder about rigging a cordless drill pack to plug in.

                      You can check the float voltage but ~28.0V for the pack, and the smart charger can be missing an equalization phase which is not needed for AGM/gel- but in reality the two packs would get imbalanced which kills them fast due to the high discharge rate.

                      Likorall overhead lift Service Manual no electronics details though.
                      Attached Files

                      Comment


                        #12
                        Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                        best place in the u.k. to hunt lead-gell batteries is probably Rapid Electronics
                        https://www.rapidonline.com/lead-acid-batteries

                        Comment


                          #13
                          Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                          Hmm… why not getting rid of the battery all together and just put a heavy 24VDC PSU in there?

                          Comment


                            #14
                            Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                            power failure could be an issue if the person needs to take a piss

                            Comment


                              #15
                              Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                              Originally posted by CapLeaker View Post
                              Hmm… why not getting rid of the battery all together and just put a heavy 24VDC PSU in there?
                              Because the hoist floats on a pair of ceiling tracks to cover an area about 3m by 4m. There is no permanent power coupling to the hoist - just the handset whenever it is docked.

                              Comment


                                #16
                                Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                                Originally posted by stj View Post
                                power failure could be an issue if the person needs to take a piss
                                Doesn’t matter that much… it will dry after a while! It becomes problematic if it’s #2. I don’t think this little battery can hold out for more than 2hrs in a power outage situation and being used once. That thing gotta be flat.

                                Originally posted by DanielCoffey View Post
                                Because the hoist floats on a pair of ceiling tracks to cover an area about 3m by 4m. There is no permanent power coupling to the hoist - just the handset whenever it is docked.
                                Aah! That’s how they get around having a “clean install” an no hanging wires from the ceiling.
                                Hmm… I can get 2 SLA batteries for 40$ tax incl?
                                I think your problem with the expensive battery pack is you are using YUASA. While they are good, I find them overpriced a lot, specifically since the hoist isn’t using a more common battery size like a 12V 7Ah one. Check if you can’t modify something in order to fit.a different style SLA and while you at it, check the charging voltage too.
                                Last edited by CapLeaker; 03-08-2023, 05:40 AM.

                                Comment


                                  #17
                                  Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                                  I have just had a look inside the hoist again and there is absolutely no more room for any larger cells. Not one dimension has any room in it at all.

                                  The reason for upside down mounting seems to be because of the risk of short circuit to the aluminium housing (although there is actually clearance) but the cynical side of me thinks that cutting 5cm off the wiring harness was a bigger saving than the longer wires and a bit of tape. I will get some 4.8mm 14AWG Faston M-F extensions with enclosed ends and see about flipping the cells next time I have to change them.

                                  I measured the fresh off the charger voltages today and they are as follows...

                                  Across the pair : 26.77V
                                  Cell 1 : 13.38V
                                  Cell 2 : 13.39V

                                  They are surprisingly well balanced.

                                  I agree that a LiFePO4 cell may have difficulty delivering the amount of grunt that is needed as the hoist is lifting an adult straight upwards without any significant gearing.

                                  I will stick to SLA cells for now but perhaps invest in a smart SLA tender for a once a year recondition. I can't find a good 24V smart tender to replace the existing dumb charger because the 2.4Ah capacity is off the bottom of many of the available chargers. This is a shame as the good ones have a periodic check once charged which would prevent the batteries having to stay on charge all the time.

                                  Comment


                                    #18
                                    Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                                    why not put a box on the floor and run long thick cables up to the original box.
                                    then use BIG batteries?

                                    Comment


                                      #19
                                      Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                                      As I said above... the hoist that contains the batteries floats on rails around the entire room. It only ever connects to the walls when the handset is placed in the charging cradle.

                                      Comment


                                        #20
                                        Re: Likorall 200 Ceiling Hoist - Lithium battery conversion

                                        How about modifying the box on top, cut it open and make a bracket to fit the new battery size to hold it in place?

                                        Comment

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