two 109s on 1 dc power suply
10-12-2005, 10:47 PM
#1
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two 109s on 1 dc power suply
hi,I am getting into glo to electric conversions with big lipos for big airplanes,QUESTION:got an astro flight 12v power suply,can I run 2 109s chargers at the same time with this power suply.?if not what power suply do you recomen,Thanks a lot for your help.
10-13-2005, 05:28 AM
#2
RE: two 109s on 1 dc power suply
People run two chargers from the same power supply all the time. The question is what is the current rating of your power supply?
Use wattage of the largest batteries you will be charging to help determine the power supply requirements. Multiply the voltage and the current ratings of the largest packs you will ever use. 7.2 * 4000 mA = 28800 or 28.8 watts. If the power supply puts out 20 amps at 13.8 volts it is 20 * 13.8 or 276 watts. Adding and subtracting wattage will give you the answer. Leave a little fudge factor as the power supply and chargers are not 100% efficient, but usually run around 80%. So for the power supply use 80% of 276 watts as the power available to charge batteries.
John
Use wattage of the largest batteries you will be charging to help determine the power supply requirements. Multiply the voltage and the current ratings of the largest packs you will ever use. 7.2 * 4000 mA = 28800 or 28.8 watts. If the power supply puts out 20 amps at 13.8 volts it is 20 * 13.8 or 276 watts. Adding and subtracting wattage will give you the answer. Leave a little fudge factor as the power supply and chargers are not 100% efficient, but usually run around 80%. So for the power supply use 80% of 276 watts as the power available to charge batteries.
John
