Want to make a 12VDC charger

Discussion in 'General Electronics Chat' started by sh3r, Jul 27, 2014.

  1. sh3r

    Thread Starter New Member

    Jan 8, 2014
    2
    0
    Hello all!!:)

    Its my first post on this fourm so if i do something wrong sorry in advance.

    i have a 220VAC--->24VDC transformer. is it possible that i can make a 12VDC charger with it? Also i want to measure with multimeter about the Amps of this transformer. i search from google many time but never find any method or tut that i can understand

    any advice idea will be welcome thanks in advance.
     
  2. Lestraveled

    Well-Known Member

    May 19, 2014
    1,957
    1,215
    - What kind of 12 volt battery do you want to charge?
    - Do you know how many amps the transformer is rated for?
    - What is your skill level as far as building electronics?
    - Do you have a good source for parts?

    Mark
     
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  3. sh3r

    Thread Starter New Member

    Jan 8, 2014
    2
    0
    thanks for your reply .
    about battery its 12Vdc
    about Amps i already ask how to measure with multimeter.
    about skill level i read too many tuts on google but no practical.
    Yup i have a market near to me .

    and yes i was soldring from last many years
     
  4. AlphaDesign888

    New Member

    Jul 27, 2014
    189
    10
    You are going to need to current limit the charging. You want 20mA trickle charger?
    Or you prefer fast charger?
     
  5. ian field

    Distinguished Member

    Oct 27, 2012
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    784
    The question asked by the other contributor was more likely as to what battery chemistry? For instance if you charge lithium cells without the correct end of charge cut-off; it will vent with flaming gas and burn your house down. Nickel batteries are a bit less dangerous - but they can still burst if you overcharge them enough to gas. Overcharging can warp the plates and cause shorted cells in a wet lead-acid, and its generally best not to gas off all the electrolyte from a sealed lead acid.
     
  6. MikeML

    AAC Fanatic!

    Oct 2, 2009
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  7. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Does your transformer have any markings on it to indicate its input or output rating?
    What is the mAh rating of the battery?
     
  8. AlphaDesign888

    New Member

    Jul 27, 2014
    189
    10
    Nice. And that is all you really need for an no frills cheap SLA charger that could be built in an couple of hours using common parts.
     
  9. AlphaDesign888

    New Member

    Jul 27, 2014
    189
    10
    Current flow positive to negative but electrons go the other way from negative to positive, yet textbooks define current as (n) quantity of electrons. Confused?
     
  10. wayneh

    Expert

    Sep 9, 2010
    12,151
    3,058
    Nope. Not about that, at least. ;)

    Now if you want to talk about some tax forms, that's a different story. :eek:
     
  11. wayneh

    Expert

    Sep 9, 2010
    12,151
    3,058
    Welcome, and so far you've done nothing "wrong" except not supply enough detail. We're patient.

    Yes, you can absolutely make one. But the details requested by others will determine whether it is practical, and whether the project might be too much for a beginner. (No offense, but I have to assume you are a beginner.) Lead acid batteries are relatively easy, lithium batteries are difficult.
    It's difficult and the MUCH preferred approach would be to find the labelled specifications from the manufacturer. If that is impossible, start by measuring the DC resistance of both sides of the transformer using your multimeter. That will give a rough idea to folks here what you have. A photo would help as well, but be sure to include a guide to the SIZE of the transformer and any information about where it came from.

    The question is, how much current can I draw from the transformer secondary without the transformer overheating and destroying itself? Is that level of current useful for charging my battery?
     
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