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Old May 18, 2015, 06:22 PM
Waazzup is online now
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Help!
Battery problems!

Hello everyone! I'm having problems with my battery. When i connect the battery to my quad the KK2 (FC) just light up the backlight and no menu text comes up. And if I am fast enough I can arm it and when I try to throttle up the motors go really slow until they completelly stop. I changed the battery and everything worked just fine.

When i plug this battery (the bad one) at the charger, the display that shows the voltage is now less brighter than it used to be and it tells me that it's almost full, and when I try to charge it the display becomes normal and it tells me that the battery is almost empty. Here is a small video to illustrate what i've just said:

Battery problems (1 min 7 sec)


My question is... can I save this battery? or is it already garbage?

thank you
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Old May 18, 2015, 06:39 PM
kiwihornplayer is offline
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Your battery is nowhere near fully charged - it is nearer to fully discharged. Each cell should be showing 4.18v-4.2v when fully charged with total at 12.5v-12.6v.

When you plug it into your quad there is sufficient current to light up the KK2 but as soon as throttle is advanced and the the motors start drawing serious current ESC decides the battery is flat and stops the motors.
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Old May 18, 2015, 07:06 PM
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That battery is on empty. Charge it to ~4.2 volts/cell.

mw
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Old May 19, 2015, 08:54 AM
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When you say it almost fully charged in your video it's showin a voltage that is lower than you should ever take it. I believe that was a 3 cell pack so fully charged would be 4.2 volts per cell 12.6 volts total.
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Old May 19, 2015, 10:55 AM
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Maybe it's because I am new .... but that is the strangest charger I have ever seen. I have to agree with the others, that battery is no where near charged, it is also way way way out of balance, at least it looked that way before you plugged the DC input in, then it started popping out numbers that scared me ..... what is that 2.5? of cell voltage that is really really bad.

I think a better charger is probably what is needed also.

edit:
After more review .... this is a 30W charger with input voltage of 9-16V and input amperage to 1500mAh.
The supply you are using is the absolute minimum, 9V 1A, that's about 9Watts, that should take it about ..... an eternity to charge that 4000mAh battery. I am really unsure how they can get 30W out of 16V at 1.5A .... must be the new math!

I would grab my $5 harbor freight meter and measure the voltage of the pack on the XT60 jack ... to see what the pack voltage really is, if it is 6.8V as the DC-4S states when you have the power plugged in and it should be charging .... I would get that thing outside and give it a good funeral. If it is really 10.5 volts as shown without the power plugged in, the there is most likely a problem with that charger. The fact that either way the cells are out of balance drastically between highest and lowest leads me to believe it is a bad charger. But check that battery.

And get a much better charger ..... That is a $30-$50 battery .... at least charge it with a good charger, others will recommend a good AC/DC charger from HK, Personally I use a 50W HiTec X1-AC or a iCharger 206B, the latter needs a $50 power supply but I can charge that 3S 4000 pack you have in 1 hour .... and maybe 30 minutes if it is capable of a 2C charge rate or higher - I don't go higher than 2C charge, law of diminishing returns at higher rates doesn't yield as my time saved.
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Last edited by SilverSport; May 19, 2015 at 11:37 AM.
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