Shipment arrived quickly. The packs arrived well balanced and at storage charge.I flew these in an EFlite twin 64mm A-10 Thunderbolt 2 for 3 cycles each before charge/discharge testing them. My throttle settings were between 1/2 and 3/4, using normal kinetic energy management for scale flying. The packs came down mildly warm, discharged to 3.8V/cell. In RC aircraft, it is advisable to allow for go arounds on missed approaches/landings. Also, I prefer to land at storage charge; it simplifies battery storage/management. Flight times were around 4 minutes, 50 seconds. This was perfectly acceptable performance for me, given what I paid. Your mileage may vary...After flight cycling, the packs were once again balance charged, using an ISDT SC-620 balance charger with internal resistance measurement capability, then discharged on a Maynuo programmable DC load with a mAH totalizer built in.Controlled charge/discharge test results:- Internal Resistance/cell averaged 6.5 milliOhm- Charge Voltage 4.20V/cell- Discharge voltage cutoff 19.2V, or 3.2V/cell- Discharge current 4.95A (unbalanced)- Recovery voltage after discharge was 20.05V, or 3.34V/cell- 4320 mAH flowed during discharge testing to 3.2V. This was reasonably close to the claimed 4500mAH capacity at 3.2V/cell. However, other pack brands I have tested perform better, having 80% or more of the stated capacity when discharged to 3.6V/cell. This is probably the reason these are cheaper than other brands. You get what you pay for, but Youme Power didn't lie.