I am currently testing out how mounting the battery lower affects the flight characteristics of the 9958. It seems like it’s improving the pivot on bank turns…but I need further testing and/or feedback from others.
Alternative Battery Mount Location
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One response to “Alternative Battery Mount Location”
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The charger has a fixed plug for North American otuelts. The input is rated 100-240VAC, 50-60Hz. The output is rated 4.2VDC, 350mA (it’s about 4.6VDC open circuit). There is an LED that lights dark yellow during charge, and green when charge is complete and when no battery is connected.The LED actually starts to become a lighter yellow when the battery reaches 4.1V, a lighter yellow-green at 4.15V, and is green at 4.2V. If you only charge to 4.1V, you will get more cycles; but if you charge to 4.2V, you get a longer flight time it basically averages out.During my testing, this charger only put out its rated output on extremely discharged batteries and just for a minute. It is typically only putting out about 250mA after 5 minutes, with the battery at about 3.87V. The battery will reach 4.1V after about 40 minutes. It takes another 15 minutes to reach 4.2V, which may give you an extra minute flight time.So you can see why I’m a little dubious about people claiming that this charges their battery in 15-20 minutes. If true, I have to assume their batteries are old and only give a couple of minutes flight time. I usually get about 7-8 minutes.Still, this will charge the battery 20-40 minutes faster than the USB cable charger, and the LED gives a reliable indication of when the battery is filly charged. I’m only giving it 3-stars because the output is weak (which is probably good for a single 150mAh battery I use 2 in parallel for 300mAh, with a 1.5 hour charge time, and a 15-16 minute flight time), and it would be nice if the voltage was limited to 4.2V to minimize overcharging the battery.I also measured the USB cable charger. It puts out about 250mA max, and the open circuit voltage is about 4.6V. The battery reaches 4.1V in about 60 minutes, and 4.2V in about 85 minutes. The USB plug will start an occasional dim blink at about 3.93V and 35 minutes; a dim glow/blink at about 3.96V and 40 minutes; and a dim glow at about 3.99V and 45 minutes. The glow will get brighter as the voltage increases. After about 2 hours, the battery voltage is 4.3V and climbing.With either the wall plug charger, or the USB cable charger, since they both have an open circuit voltage of 4.6V, I can only assume the battery will keep increasing in voltage until the safety circuit in the battery cuts off the charge. This may ultimately protect the battery from failure, but is still not good to charge LiPo batteries over 4.2V. Do not leave the battery on either charger for extended periods.
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