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B&S mower aku instead of batteries - 10.8v li-ion battery on 12v gel battery

jogma 9159 29
This content has been translated » The original version can be found here
  • #1
    jogma
    Level 11  
    Hi to all,

    Equipment:
    lawn mower Stiga 53seq 4 b with engine Briggs & Stratton 775 IS (instart) - electric start
    10.8 V battery 1.45 ah / 15.7 Wh

    Can you replace the set with a 12v gel battery, e.g. 9 Ah for about PLN 100 instead of a 10.8v battery? It is a shame to spend PLN 350 on a battery that will fall after 2 years. What do you think? Could this be done? Will the starter be damaged at higher voltage? What is the best way to go about it?

    I will be very grateful for any tips.
  • Helpful post
    #2
    jarcecz
    Level 17  
    From the voltage point of view, there is no problem (li-po 10.8 is really 10.8 V-12.6V) the question is whether you will get it right. aku li-po certainly had protection whether in the mower or just in the battery I do not know. unless they are battery NI-Cd then it will be easier but if the nap over 12 V will not affect the starter I do not know
  • Helpful post
    #3
    szybki105
    Level 17  
    What technology is the original Li-ion, Li-pol, Nihm battery made of? A 10.8V output voltage would suggest any of the above. Knowing this, you can also consider regeneration, it should be cheaper. There are many companies that do this, or you can do it yourself.
    As for the conversion to a 12V gel battery, it is difficult to say if it would hurt.
    Is only the starter or ignition module powered from the 10.8V battery? Is this battery charged while the mower is running or is it a separate charger?
    The first thing to keep in mind is the higher tension, which Jarcecz has already mentioned
    The voltage of such a freshly charged 12V gel battery can be from 13.8 to about 14.5V (depends on the charger)
    And the voltage of the original charged battery is probably around 12.6V.
    The difference is small, the starter motor itself should withstand such a difference in voltage, unless it is used too intensively, theoretically it can overheat.
  • #4
    jogma
    Level 11  
    Thanks for the answers.

    It is a lithium-ion battery with an external battery, as in e.g. screwdrivers. I was wondering if I would add some L7912 12 V 1.5 A stabilizer, then maybe the problem with higher voltage would be solved, except that I read it because I don't know it, I'm just trying to save some money, the battery costs PLN 50 and this system 350 ... As for overheating, the starter spins max 5 s and fires up so you should not overheat during this time.


    I will add that the battery died a month after the 2-year warranty.
  • Helpful post
    #5
    web69
    Level 30  
    Come on with these stabilizers, do you know what current the starter draws? A charged acid gel battery is 12.3-12.6V instead of 14 ... Connect the iron and check
  • #6
    jogma
    Level 11  
    web69 wrote:
    Come on with these stabilizers, do you know what current the starter draws? A charged acid gel battery is 12.3-12.6V instead of 14 ... Connect the iron and check


    hi, i don't know what current it consumes, there is no sticker and in spare parts unfortunately it is not described. I guess the size of this current does not make much difference whether the battery will be 4Ah or 7Ah?

    Gentlemen ... I'm trying to connect the battery, however, I noticed that the mower is mounted micro switch and that the battery comes out 4 wires ... Please, look at the diagram and hint how to attach it to the battery where there is only plus and minus. Especially, I don't know what kind of cable goes from the battery to the microswitch and how to connect it to the battery.

    1. Picture diagram
    2. picture - picture of the microswitch with 2 plugs coming out - to the ignition key and the battery as in the diagram.

    B&S mower aku instead of batteries - 10.8v li-ion battery on 12v gel battery

    B&S mower aku instead of batteries - 10.8v li-ion battery on 12v gel battery


    Please help
  • #7
    szybki105
    Level 17  
    This micro switch is what the task can be, what is it turned on, any pull cord?
    You could use pictures of the rest of the electrics, this battery with an "external battery" too. Does the battery itself also have four contacts? After the diagram, it can be concluded that there is an additional relay or electronics to switch on the starter. The inrush current should not go on the micro switch.
  • #8
    jogma
    Level 11  
    szybki105 wrote:
    This micro switch is what the task can be, what is it turned on, any pull cord?
    You could use pictures of the rest of the electrics, this battery with an "external battery" too. Does the battery itself also have four contacts? After the diagram, it can be concluded that there is an additional relay or electronics to switch on the starter. The inrush current should not go on the micro switch.


    I was a little vague when talking about the external battery, I already explain:

    this is the battery:
    B&S mower aku instead of batteries - 10.8v li-ion battery on 12v gel battery B&S mower aku instead of batteries - 10.8v li-ion battery on 12v gel battery

    this is the charger:
    B&S mower aku instead of batteries - 10.8v li-ion battery on 12v gel battery B&S mower aku instead of batteries - 10.8v li-ion battery on 12v gel battery

    this is what microswitch looks like:

    B&S mower aku instead of batteries - 10.8v li-ion battery on 12v gel battery

    these are the cables coming from the battery:
    B&S mower aku instead of batteries - 10.8v li-ion battery on 12v gel battery

    1 and 2 are connected and 1 goes to the starter and 2 goes to the ignition
    3 (red) for starter
    4 for microswitch v7-6c37e9-036, exactly like on this page:
    link

    according to information on this page, this switch is max. 15A. I suspect that the microswitch with this metal plate connected in some way to the motor gives current to the coil at the right time.

    here again the diagram:
    B&S mower aku instead of batteries - 10.8v li-ion battery on 12v gel battery

    and I repeat the question of how to connect it through a gel battery without damaging the starter and, above all, a microswitch with these parameters:

    B&S mower aku instead of batteries - 10.8v li-ion battery on 12v gel battery

    please help
  • #9
    szybki105
    Level 17  
    jogma wrote:
    and I repeat the question of how to connect it through a gel battery without damaging the starter and, above all, the microswitch with these parameters

    Connect the battery in accordance with the polarity directly to the starter, through a solid switch or relay, e.g. dedicated to starters in scooters, motorcycles. Maybe a solid switch is enough, it is not known how much current the starter draws.
    That's when it comes to just turning the starter. But it is not known if it is enough for the mower to start. Something else needs to be done with the coil leads, and it is not known what the microswitch is for.
    In the pictures of the original battery, you can see the plus and minus markings and two additional pins, maybe it is a li-ion balancer connector or maybe something else, the diagram does not show where these individual pins are connected, where plus where minus. Microswitch also has a specific arrangement of contacts and the diagram does not show how it is connected. Without this equipment and without distance measurements, it is difficult to advise well.
  • #10
    emdi90
    Level 2  
    The battery comes out with 4 contacts, the two extreme are Plus and Minus (There is, say, 1V on them) to the starter, the circuit is interrupted by a switch that closes when we grab the handle and unblock the chamomile. Now we will start firing, in this case it is solved in the battery, there is a microcontroller there and when the pressed firing (red start) the voltage from the PLUSA battery is given to the connector next to it and then the system will let two MOSFETs (such small relays) opened and a voltage of 10.8V goes on the starter. The starter is like 12Volt and 12V is suitable, but to bypass these system with MOSFETs you will need to add a relay to the firing button. To do, is anyone willing to sell an old battery? It may be broken, in part ?
  • #11
    kris86k
    Level 11  
    Hello. I have a question how to check the battery? Do you need to shorten the two internal pins or give some voltage? I want to charge it with an external source because firing works once and not once.

    The battery is IS12B.
    Pins: - | TH | E | +
  • #12
    dizba
    Level 32  
    jogma wrote:
    this is the battery:

    Enter on the Allegro: 18650 plaques.
    You will replace with an ordinary soldering iron.
  • #13
    kris86k
    Level 11  
    But nobody asked about it and it is not that simple because there are 3.6v cells and high-current ones.
  • #14
    dizba
    Level 32  
    kris86k wrote:
    it is not that simple because there are 3.6v cells and high-current ones.

    Very simple. And on the Allegro you have 20 and 30 amps.
  • #15
    kris86k
    Level 11  
    As I know it, but it's worth mentioning so as not to make yourself a torch from the battery.
    However, I asked for something completely different.
  • #16
    dizba
    Level 32  
    kris86k wrote:
    Do you need to shorten the two internal pins or give some voltage?

    If you don't want to go into space, don't touch them. Any actions are only positive and negative. If they don't have at least 12v after charging, the battery is repairable.
  • #17
    kris86k
    Level 11  
    I see you haven't read the topic from the beginning. This is not a typical battery. The current is "released" only after the signal is sent to the appropriate pin through the internal mosfets in the battery. That's the problem.
    I regenerate my batteries and do not need basic advice. I know the li-ions quite well, I know what their testing, replacement, welding, soldering, etc. is all about.
    It is a pity that such an experienced forum user litter the topic without even getting acquainted with it.
  • #18
    dizba
    Level 32  
    kris86k wrote:
    I regenerate my batteries and do not need basic advice

    With such experience you have not dismantled this battery yet? Show me what's inside.
    If the starter does not turn you sometimes, check if it can be turned by hand. Because it doesn't have to be the fault of the battery at all.
  • #19
    kris86k
    Level 11  
    The equipment does not belong to me, I do not have it in place. I took the battery to check but it came out. The mower itself is under warranty (the warranty is 3 years, more than two years have passed) but the battery is probably over, but I'm not sure about it, so I haven't touched it yet. The equipment would go to the service, but the service requires the mower to be sent to them (another city) and there is a problem to pack because the mower is quite large.
    A colleague of emdi90 wrote that the signal is fed from the plus to the next connector, but I do not fully understand what it means. Plus with the pin next to it is shorted and then the voltage appears on the pins?
    I know that the voltage to the starter is given directly from the batteries marked as + and - but the voltage is not there. There are 3 pins in the mower. Two external and one additional internal at + marked as E.
  • #20
    dizba
    Level 32  
    There is nothing on the internet about this battery. And nothing follows from the pictures above. I would give the mower voltage from a normal car battery and see what will happen. I do not want to believe that there is a relay in the battery. The charger would also have to turn on this relay for charging. Some paranoia. In addition, this battery is without a balancer, so the service life is short.
  • #21
    kris86k
    Level 11  
    The battery may have a built-in balancer, and a separate circuit, as one of my colleagues writes, turns on the voltage with mosfets.
    There are already many batteries so that the balancer with the charger is inside, and only the power supply is connected. Sometimes even an ordinary DC circular "bush-pin" connector.
    Here, the solution is perhaps due to the fear of short circuit and fire. The risk of short-circuiting 3 pins at once is much less than two.
    The charger can turn on the battery in the same way as the lawn mower, unfortunately I do not have it at hand at the moment.
  • #22
    lukaszmi221
    Level 2  
    Hello. I have the same problem with this engine. I bought a mower used without a charger with a discharged or maybe even damaged battery. To quickly check if the mower works, I connected the 12v batteries from the screwdriver to the + and- contacts and it fired, but the starter with this connection is spinning all the time.
  • #23
    kris86k
    Level 11  
    If you get acquainted with the topic, everything will become clear.
    Write what you want to achieve. The easiest way is to buy a new battery, but I guess you want to avoid it.
  • #24
    lukaszmi221
    Level 2  
    At the moment, I wanted to find a way to charge the battery, e.g. using a Devalt charger for 10.8v batteries. I want to avoid both buying a new battery and a charger that is not cheap. If it turns out that the battery is damaged, I will rework the installation in the mower for Devalt batteries because I have some equipment of this brand and it would be the most advantageous for me.
  • #25
    kris86k
    Level 11  
    As far as I remember correctly, there are three pins in the mower. Check if after pressing the start lever and the starter button there is a short circuit between any of the plus or minus pins with the third pin. Press and release the button then you will see a change on the meter because it may show something even without pressing the starter.
    It's best to also open the battery and take photos.
  • #26
    tpieczka
    Level 11  
    For me, this battery is between + and - about 0.1V. The mower went silent today, the LEDs show 100% charged. After inserting it into the charger after 5 minutes, it already showed that the battery was charged.
    How to check this battery, is it dead or maybe a charger, starter, etc.?
    Stiga Twinclip mower
  • #27
    kris86k
    Level 11  
    If you have any electronic experience, try this: set the mower to start (I don't know how it works in your model), probably two people will be needed. On the mower's pins, which are marked as + and - on the battery, connect the power supply directly from a 12v battery with a minimum capacity of 10A, it must be a battery, an ordinary power supply is not enough. It can be a scooter battery, car battery, etc ... Watch out for short circuits and correct polarity connection! The starter should crank without depressing the starter button. If the mower starts up with a fault on the battery or the starter button / system.
    The fact that the battery shows 0.1V does not mean that it is definitely damaged.
    Be sure to let me know how it went.
  • #28
    tpieczka
    Level 11  
    kris86k wrote:
    If you have any electronic experience, try this: set the mower to start (I don't know how it works in your model), probably two people will be needed. On the mower's pins, which are marked as + and - on the battery, connect the power supply directly from a 12v battery with a minimum capacity of 10A, it must be a battery, an ordinary power supply is not enough. It can be a scooter battery, car battery, etc ... Watch out for short circuits and correct polarity connection! The starter should crank without depressing the starter button. If the mower starts up with a fault on the battery or the starter button / system.
    The fact that the battery shows 0.1V does not mean that it is definitely damaged.
    Be sure to let me know how it went.


    The battery is functional, one of the cables in the plug is damaged, which connects to the cable from the starter button.
    I am trying to patch it up because I do not see such cables to buy with such a tubular connector and the cable is probably damaged at the plug itself.
  • #29
    kris86k
    Level 11  
    Then tell me where this conclusion came from. Maybe it will be useful to someone in the future.
  • #30
    tpieczka
    Level 11  
    kris86k wrote:
    Then tell me where this conclusion came from. Maybe it will be useful to someone in the future.

    I checked the batteries (5 years old) in another mower in the store, then found this broken cable.
    I patched it and it works.
    Best regards.