F210 LIPO battery charging multiple battery's

Discussion in 'Walkera F210' started by Shadow636, Dec 8, 2016.

  1. Shadow636
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    Shadow636 New Member

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    The standard GA009 balance charger you get with the F210 has an output of 3.3A to charge the 14.8v 1300mah 4s battery.
    I have an overlander RC 100 dual balance charger with 2 balance boards so I can charge 12 battery's at one time. I have 6 battery's and charge 3 battery's of each board so my question is what Amp should I set the charger too is it as simple as 3.3A x 3 or is this to high or to low.
    Thanks for your help.
     
  2. bjr981s
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    I don't believe those number are correct. Our even close for the stock charger.

    You should only charge at 1C. So a 1300mah Battery should be charged at 1.3 Amps Max the number of cells are irrelevant. Some batteries will take a greater than 1C charge but that would written on the battery.

    If you are using a normal battery charger. And by normal I mean it charges through the main discharge plug and drains through the balance plug to balance. Then if you charge via a multi charge extension. Use the amp factor of [1C times the number of batteries - 1C]. In your case 1.3 x 3 - 1.3 = 2.6 Amps.

    The reason for this is you must charge in parallel slower than you do for a single battery.

    As soon as you attach the three batteries to the replicated JST XH balance socket the three batteries will start to cross charge at the cell level.

    The cell with the highest charge will discharge into the cell with the lowest charge. If these batteries are reasonable quality they should have the same internal resistance.

    The major charge is going through the main discharge plug and the current is the same for all cells in the battery.

    The balance circuit in the charger is not a high current discharge circuit but a slow drain.

    The upshot of this is that If you try and charge too fast the Cell with the highest voltage will get the same charge rate as the cell with the lowest.

    This makes balancing the battery a real problem. So charge slower and allow the balance circuit to drain correctly. Not doing so will cause the Cell with the highest charge to become damaged. (LiPos cannot be floated)

    Charging batteries in parallel is no big deal unless you forget this. Some LiPos are already configured in parallel but they self balance prior to being put on the charger.

    You can always play it safe and connect up the batteries ready for charging but not start the charge. They will slowly self balance and can be safely charged at 1C times the number of cells.



    Cheers
     
  3. Shadow636
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    Shadow636 New Member

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    I got the charger information about the output from the F210 manual on page 17, I get way you say about the 1C times the number of cells I've copied this next bit from dronetest.com

    To convert your battery C charge rate to Amps you simply need to multiply the battery capacity by the C rating. So lets say we have a 2200mAh battery with a charge rate of 2C. So the maximum current we can charge this battery at is 2.2Ah x 2 = 4.4A. Similarly lets say we want to charge a 5100mAh battery at 1C, the max current we will need to set on our charger is 5.1Ah x 1 = 5.1A

    I was under the impression from their site that it would be 1.3 x 4c
    I think the reason the output current on the standard balance charger is set to 3.3A is because it can also charge 3c (11.1) as well

    You mention 2.6A is this per battery?
    Sorry for this but I'm totally confused at charging multiple battery's as their is so much misleading information about and the last thing I want is to blow up an LIPO battery
     
  4. bjr981s
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    This is a Max Spec number. Its a 60Watt charger so it will not catch fire if you put a load that draws 3.3 Amps from it. It does not mean that the battery charger is charging at 3.3A.

    3.3 Amps is the over the max recommendation for their Voyager 3, Tali and Scout 6 and 8S batteries of 3A max.

    Its a 4S battery not a 4C charge battery. Meaning it has 4 Cells.

    No. When you use a parallel charge board you set the Max charge current on the Charger. So set the Charger to 2.6A max. Remember that this is a max charge rate, the charge rate will fall off as it approaches max charge on the batteries to assist in the final balance process.

    Don't be sorry these are good valid questions and some people do blow up or at least damage their batteries by overcharging and by over discharging.

    Charging on a parallel charge board is complex. You can charge different capacity batteries at different levels of discharge if you know what you are doing.

    If you stick to the formula I quoted and only charge identical spec batteries you should be fine.

    So on Discharging do not Discharge below 3.6V per cell. So on a 4S thats 14.4V. max charge is 16.8V the quoted number for a battery is its nominal value. that is 3.7V per cell or 14.8 on a 4S Discharging below 3.6V per cell has an exponentially deleterious effect on the lifetime and number of cycles of the battery.

    Cheers
     
  5. Shadow636
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    Shadow636 New Member

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    Ah right that makes sense I don't intend to discharge the battery as such I'll put all 6 into storage mode on the charger and then once that's finished it's charging cycle I'll store them over the winter or until the weather gets dryer at least. Before I set the charger to the 2.6 how come it's 1.3x3 but then -1.3 giving you the 2.6 and many thanks for your help and explaining this what seems to be a grey area
     
  6. bjr981s
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    The max that you should charge the batteries is 1.3A per single battery alone.

    So if you set it to 1.3 x 3 for the 3 batteries they would all be charging at their maximum rate.

    But if one battery has a higher charge than another. It will also start to charge the lower charged battery simultaneously.

    So the charger is charging at max and the higher charged battery is pushing more current through so you get a greater than 1.8 Amps through the lowest charged battery.

    By reducing the max current from the charger you provide a margin for the cross charge of different level discharged batteries. (within Reason)

    Don't have a almost fully charged and a completely discharged cell in the mix. This is based on you flying the 3 batteries and then recharging them from approximately the same discharge level.


    Does that make sense and explain it well enough?

    If you are going to store them for quite a while make sure that they are charged well over the 3.8V per cel. (3.81V to 3.85V) make sure you buy a good lipo cell monitor.

    They will slowly discharge in storage. I check all my lips in storage very 4 to 6 months and re storage charge them.

    I have over 300 Amp hours of LiPos in storage.

    Cheers
     
  7. Shadow636
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    Shadow636 New Member

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    Thank you so much for the explanation I understand now, when I fly I keep my flown batteries separate so they are always charged at the same rate and time. I have a monitor it's a small one that tells me the battery voltage and each individual cell voltage within the battery will this suffice or should Invest in a more expensive one or should I ask what type of monitor do you use?
     
  8. bjr981s
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    I have many.

    If you want real accuracy on a lipo meter you need the Futaba BR-3000. It is super accurate to 3 decimal places.

    I like the Turnigy Dlux or the original Sky-RC versions the Turnigy is a clone. Its nice and small quite accurate and auto-balances.

    I also like the Generic brand Checkers that do the 150 W battery discharge. They are handy if you go out for a days flying and have a bunch of fully charged batteries left over and you want to take the edge off them.

    The other key tool is an IR meter. If your charger does not contain that functionality.

    An IR meter measures the internal resistance of the individual battery cells. Not only does it tell you the quality of the battery.(Lowest is best)

    It also tells you if one cell has gone bad If a cells internal resistance has gone high compared to other cells in the pack. Its about to expire. Throw it away it will cost you a model.

    Most people just blame the model manufacturer for their battery problems of their own making.

    Cheers Brian
    .
     
  9. Shadow636
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    Shadow636 New Member

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    Fantastic I shall look into these thanks for all your help now I can charge my batteries safe in knowledge I won't blow them up up putting to much ampage in them.
    Thanks again
     

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