SBH
Heliman
Location: Coralville, IA - USA
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| some of that data dosent look so good. after a single discharge you have a .7v imbalance???? I need 50 flights on my tpx 2070 to get a .1v imbalance.
and it seems to get very hot also in the description.
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Dear Wingman77,
What you have said here actually contradicts the Closing Note in the testing. The tester specifically said "This pack (and cell) remained remarkably cool with extensive discharge." In the single-cell test, the temperature never got above 140°F even after continuous 25C discharge. Two 3S packs were tested. One of the pack is projected to have a temperature of 170°F after continuous 25C discharge while the other is projected to be around 160°F. In real-life situation, 10 to 15C continuous discharge is more of a norm and the temperature of the pack is about 120 to 135°F in the two tests. These are really low temperatures.
Please also note that voltage differential does not equal to cell imbalance. Our packs hold voltage extremely well; more than 85% of the capacity is above 3.3V per cell. All the users we have talked to appreciate the robustness of such discharge characteristic as you get a lot more "usable capacity" compared to other brands. The flip side is that, as MrMel had pointed out, there is not much capacity below 3.2 volts; when the voltage starts to drop, it drops fast. As a result, even the slightest difference in cell capacity can lead to seemingly large voltage difference between cells after a deep discharge. This is why the tester studied the alternative cut-off voltage. If you stop the discharge at 3.2V per cell, the voltage is actually quite balanced. As the tester concluded in the Closing Note: "The cells appeared to be quite closely matched, and tracked within 10’s of mV right up to the ‘knee’ in the discharge curve."
It may seem alarming when you see one cell having a rather low voltage after discharge, and we know for a fact that this poses challenge to some chargers. The LiPo user community has been conditioned to believe voltage balance is everything. That is true for old LiPo technology as over-discharge of a single cell usually proves detrimental to the entire pack. With the low voltage after 15C current draw in the tests, you would have had a puffed pack with many other brands. This just goes to show the robustness of our technology. We have circumvented the over-discharge problem and low voltage in one cell in fact poses no issue at all. In return, you get a longer, stronger flight. I do like to reiterate that it is utmost important to balance-charge our packs to ensure all the cells in the pack "start" balanced.
In fact, our pack held the voltage so well that it caused the testing equipment to over-heat as indicated by the thermal-trip in the first chart in the report. Voltages on many other brands are low and useless after 70% discharge.
All in all, our pack has got to be one of the most scrutinized batteries ever. And I'm proud to say that most if not all tests have proved the merits of our pack. I'm gathering testing data on TP and FP's 25C offering. If anyone know where I can finds them, please let me know.
Thank you for listening.
Barry H.
AirThunder |
The packs have gone through over 40 cycles with absolutely no signs of quiting.
