Solar Battery Charger & Battery

Discussion in 'General Electronics Chat' started by pyother, Mar 10, 2012.

  1. pyother

    Thread Starter New Member

    Mar 10, 2012
    3
    0
    Explanation of the "why"

    Iam a software engineer, not having keen knowledge in electronics..

    I camp often, so i badly needed a solar charging system... i got a 12v 10w panel with the following specification

    Voltage at Pmax (Vmp): 17.2v
    Current at Pmax (Imp) : 0.584A
    Open-Circuit Voltage: 21.2v
    Short Circuit Current: 0.631A
    where as my solar charge controller is 12v 10A

    The details of "what":

    as i have to carry it in my backpack.. i think of reducing the weight of battery instead of using 12v 7ah lead acid battery which itself was 1.5Kg..

    with 12v 2A Lead Acid battery or 12v 2A Li-ion battery... 25w

    Will it work..? or the battery is low in watt hours for the 12v 10A [120 Watt] charge controller..

    Please let me know..
     
  2. k7elp60

    Senior Member

    Nov 4, 2008
    478
    69
    The charging methods are different for the Lead Acid and the Li-on batteries. The Lead-acid has a charge current limit depending upon charge voltage. The Li-on has some similar specs. Weight wise the Li-0n is lighter as you know. The specifications of the charge controller need to be known if we can help you.
     
  3. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,170
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    How much power do you need, more than just light?
     
  4. twister007

    New Member

    Feb 29, 2012
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    You don't need the voltage controller if you be careful and monitor the voltage of the lead acid battery and not let it go over 14 volts for a long period of time. It won't hurt it to go over that voltage if it is not fully charged, it will just make it charge faster. You can tell if it's fully charged by monitoring the voltage after taking the charger off. If it holds around 13 volts, it is fully charged. A new lead acid battery will hold over 13 volts, and an older battery maybe 12.5 volts fully charged. If you take the caps off and see that it is boiling, it is fully charged.
    Someone else can tell you about lithium batteries.
     
  5. pyother

    Thread Starter New Member

    Mar 10, 2012
    3
    0
    Hai all, thanks for the reply...

    So it seems Li battery cant go just like that with the normal charge controller, ok.. bit heavy lead acid then..

    I just need to charge my camera battery "Output 8.4 V and 0.55 A" reads label on the camera adapter..

    My fear is whether it mess up the battery if it had 14v & more current to charge...

    Panel reads 20.1 V at full sun light
    charge regulator reads 13.5-14v at full sunlight [its under safety, Amp threatens me]

    How much Amp is considered safety to charge 12v 2Amp battery..
     
  6. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    What is the input for camera adapter? I would skip lead acid battery & use a voltage regulator, VR, IC to charge camera battery, unless you need to charge at night; then use VR from 12V battery to 8.4V, or for better efficiency[ smaller battery ], use a buck convertor.
     
  7. pyother

    Thread Starter New Member

    Mar 10, 2012
    3
    0
    Thats 220v adapter for camera.. not a 12v charger... all i need to know is whats the safety limit v & Amp to charge 12v 2a battery..
     
  8. Bernard

    AAC Fanatic!

    Aug 7, 2008
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