best high power charger

Discussion in 'Batteries & Power' started by Michael Izquierdo, Mar 19, 2017.

  1. Michael Izquierdo

    Michael Izquierdo New Member

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  2. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Michael:
    I'm not quite sure what you mean by "better." Are you looking some specific features?
    The Graupner Polaron is certainly a "good" charger.

    Do bear in mind that the more current you pump into a LiPo when you are charging it, then (a) the less total charge the LiPo is likely to take and give back when you use it, and (b) the more you are stressing the LiPo so it's useful life is likely to be shorter. And, of course, if you charge a LiPo with way too much current you will discover it goes into "sustained ignition" (i.e. catches fire).

    For those 10,000 mAH, the optimal charging rate would be 10 Amps. (Otherwise known as 1C where C is the Capacity of the LiPo in Amp/Hours (so the C for the 10,000 milliamp/Hour batter is 10).

    I certainly know that folks charge at faster than 1C, but personally, i wouldn't go above 2C (20 Amps).

    Other forum members may well have different experiences and opinions (or even "alternative facts" :rolleyes:), so I could well be wrong.

    Personally, I use the Hyperion 720i https://www.maxamps.com/hp-eos720id...ual-20a-500w?gclid=CIGtg_3559ICFQZbfgodSpoGXA with eFuel DC power supply https://www.amazon.com/SKYRC-Efuel-1200W-Power-Supply/dp/B00UCB0XKY

    I have four chargers and four DC power supplies so I can charge up to eight LiPos at the same time.

    Hope this is helpful.
    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
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  3. Michael Izquierdo

    Michael Izquierdo New Member

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    I really appreciate your input. I guess what i am looking for is the ability to charge more then 2 batteries at once.... yea and id like to push the c charging rate when possible at the right moments. Im not as concerned with battery life and more concerned with the ability of getting batteries charged quickly if in the field and I need to.

    Are there any chargers that do 8 batteries ?
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    The short answer to your question is: none that I am aware of.

    The long answer is that the limiting factor is usually the DC power supply. So, for example, imagine that you had a Giant-o-Matic charger that could charge eight 10,000 mAH Lipos at once at 2C (20 Amps), then you would need a DC power supply feeding that charger that could deliver 8 x 20 Amps -- 160 Amps!

    At full charge, each of six cells in a single LiPo would be at 4.2 volts, so just as an approximation that means 6 x 4.2 or 25.2 volts. The charger would probably need to output, oh, say, 27 volts in order actually charge the LiPo (I'm guessing on that number, but bear with me).

    That means that the charger itself is going to have be able to inject 27 volts at 20 Amps. That's 540 Watts.
    And there are going to be eight such batteries so thats 8 x 540 Watts, or 4.3 Kilowatts.

    Just for comparison a typical electric kettle (that use to boil water for tea) takes about 1.2 Kilowatts.

    I've not yet seen a Giant-o-Matic charger (in case it wasn't obvious!)

    As far as I know, everyone goes for a pretty big DC supply (the eFuel is 1.2 Kilowatts I believe), and then feeds two chargers from each one of those (I misspoke when I wrote above that I have four chargers and four DC supplies -- I have four chargers but only two DC supplies). But each "half" of the charger can only supply 10 Amps as I recall.

    I may well be wrong (but it never holds me back!) but I think most folks just use numerous batteries, chargers, and DC supplies so that they can be charging up batteries on set faster than they can discharge them while they're flying.

    On set I presume the gaffers let you suck large quantities of electrons to power your equipment. But when I've operated off the grid, the field generator that I use is a Honda 2000i, which is max. rated for 2 KW (but I don't believe it, so I assume around 1.6 KW).

    You can (and I have) ganged two of them together to get 4 KW (which is probably around 3.2 *real* KW). http://www.electricgeneratordepot.c...107152781531&gclid=CMCU4pXZ6NICFQ5EfgodWJcNFw

    Hope this helps.
    Andy
     
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