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Thread: BATTERIES BATTERRIES BATTERIES!!!!!!!!

  1. #21

    Default battery

    When a battery is recharged at an excessive rate, an explosive gas mixture of hydrogen and oxygen may be produced faster than it can escape from within the walls of the battery, leading to pressure build-up and the possibility of the battery case bursting. In extreme cases, the battery acid may spray violently from the casing of the battery and cause injury.

    ---------------------------
    hesslei.........

    SEO

  2. #22

    Default Don't try to charge Lithium Ion batteries using cheap charge

    Hi all,
    First and foremost Lithium Ion batteries are sensitive and dont take abuse....the result can be catastrophic. By cheap chargers I mean the hacked LM317 circuits. Its simple to build a LI-On charger but use some precision voltage references like TL431 and come current sensing precision resistors and comparators for designing a constant current charger(1C at max) with termination at precise 4.2V followed by constant voltage charging till current drops to 0.2C(take some security margin in this).

    asimov

  3. #23
    Senior Member Cyborg
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    Unhappy How to select suitable Battery for my robot ? -Here are few tips

    How to select suitable Battery for my robot ? -Here are few tips

    First calculate the total current on full load (in running condition of your robot)
    say for example it draws 500mA, then a 700mAH Battery will ideally give backup for 1hrs 15 Min or roughly in practical 1 Hrs, then after it will not stop working immediately but the rated voltage fill fall moderately -fast

    It is very important that the measured current of boat in full load (Running condetion and all associated mechanism in operation)

    Generally any standard geared motor takes 80-100 mA at 12V but in load conditions it may take upto 200-600 mA ,

    Generally battery (lead-acid) comes into 6V 1.3AH (1300mAH)(wight is aprox 160gms),6V 4.5AH (wight is aprox 900gms),12V 1.3AH (wight is aprox 290gms),12V 7.5AH (wight is aprox 2.25KG), 12V-120AH ...... Even More

    NimH battery comes 1.2V -700mAH,1000mAH,1300mAH,2300mAH,2500mAH (wight is aprox 50gms),
    you will need 10 such battery connected in series so that it becomes 12V ,

    Important
    *If you use 700mAH battery in series (say 10 Nos) total will be 12V-700mAH
    *dont mix different mAH battery
    * Never use Nokia or other mobile battery , it may give you bad experiance
    * China made ordinary batteries are not reliable (it may sows you full voltage in no load - but as soon you connect it to your bot or any other load it may show 10-20% of rated voltage -12V become 1.2-2.4 V
    ......
    further study
    http://onlinetps.com/forum/index.php?topic=29.0
    http://www.onlinetps.com/
    Online Component Shoppe
    Microcontrollers and Solar Robotics Stuffs at cheap rates

  4. #24
    Senior Member Cyborg
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    Default

    Very simple Lithium Ion, Lithium Poly Charge Circuit

    http://shdesigns.org/lionchg.html

  5. #25
    Senior Member Cyborg
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    Default

    Quote Originally Posted by Ulhas View Post
    Very simple Lithium Ion, Lithium Poly Charge Circuit

    http://shdesigns.org/lionchg.html
    Good one, nice & simple design
    http://www.onlinetps.com/
    Online Component Shoppe
    Microcontrollers and Solar Robotics Stuffs at cheap rates

  6. #26

    Default

    Why to spend so much money on batteries for micromouse or any other robots, when china mobile batteries works extremely well and are cheaply available? I Have used four such batteries to make a power supply of 16V when fully charged. Few batteries also have very large current capacity, around 6 Amp/hr and I have such batteries. Just go for it, cheaper and yet effective solution.

  7. #27
    Senior Member T-1000
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    Default

    6AH mobile battery??
    .... I didnt do it ! ....

  8. #28

    Default

    yup i still have it....it was quite surprising to me for the frst time but ultimately seeing is believing.

  9. #29
    Super Moderator T-1000 docel's Avatar
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    Default

    Dont fool around with Li-ion / Li-Poly batteries.
    They are quite dangerous and explode with authorized hi-tech ( expensive) chargers itself.
    Cheap / self made chargers should not be used at all.


    Remember this - you may cause damage and physical harm to innocent people because of your stupidity.

    You have no right to do that.
    docel
    ^Anything is possible..
    after YOU prove it!!

    http://bangalorerobotics.tripod.com

  10. #30
    Senior Member Cyborg
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    Default

    Quote Originally Posted by rahulcreations View Post
    Why to spend so much money on batteries for micromouse or any other robots, when china mobile batteries works extremely well and are cheaply available? I Have used four such batteries to make a power supply of 16V when fully charged. Few batteries also have very large current capacity, around 6 Amp/hr and I have such batteries. Just go for it, cheaper and yet effective solution.
    To get 16 V from mobile battery you must connect 4 seperate batteries each 4 VDC in series, In such combination Ah rating of this battery pack still remains unchanged of that of single battery itself or else your single battery must be rated for 4VDC ,6 Ah. 800mAh battery is normally availlable in many nokia handset, i can guess in your case it may be 1500mAh. Comparatively size wise if what you are saying is right then size of your battery pack will be of cosiderably bigger for micromouse

    Is it So?

    Any way what is the cost of your battery?

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