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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Paul Taylor on September 02, 2013, 06:51:29 PM
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Can we maybe start a run book so to speak on how to use batteries?
I got a new battery and did a balance charge on it. Took two hours. This is a 4s and did the charge at .1a. Is that the correct setting?
Any way i put three 1 minutes runs on this battery. Thought i could get 5 one minute flights but after third run when I plug the battery up it would give me the normal start up beeps, press the start button and the motor never started and the thing just beeped at me every few seconds. ???
Anyway.
4s Battery:
1. Balance Charge battery
2 Run the battery 5.5 munites
3 charge battery @ x amps
4. Run battery for 5.5 minutes
5 balance charge ???
Repeat?
This is a guess for me.
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The standard charge rate for a lipo is 1C not.1C. If you have a 2200mah battery, you charge it at 2.2 amps.
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Paul,
Was that 3 one minute static runs or 3 one minute flights?
Jason
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Paul, Static runs are extra stressful for your electronics. Make sure that things (ESC, Motor and Battery) are not getting HOT!! If you are just trying to run your new battery through a few new cycles (so called break in cycles), use a smaller prop and lower RPM than you plan for flying. Do not discharge a Lipo battery beyond about 80% of stated capacity (70% is safer). It is almost a kind of deceptive advertising when a battery is labeled as 3300 mah because if you draw that all out you have a dead battery that generally will NOT take a charge!!
Do you have a Watt meter?? If not, that would be a good investment. You can put the meter between the battery and the ESC and determine how many amps you are pulling. Because the wires on my watt meter are fairly long I do NOT leave it in place for a long run. I just check the amps and then remove it from the circuit. Long wires (over 10 to 12 inches) are said to be hard on an ESC.
If you are trying to determine if your setup will give you X number of minutes flight time, do a short flight of say 3 minutes and check how much capacity (how many mah) is returned to the battery when you recharge it. You do this because you will find that the amount of drain is different during flight from that of a static run. Many variables come into play during flight such as unloading of the motor, changes in component temperature, wind etc. So the proof is in flying your setup and checking the battery drain. This is why the "list your setup" sticky thread at the top of the Electric section of the forum is so useful. There you can often find proven combinations of components for the same or a similar airframe to the one you are planning to use.
Hope this helps.
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Paul,
What batteries are you using? and What charger do you have? I don't often do static runs anymore but when I do I always downsize the prop 2 or 3 sizes so I would not overload the power system.
William
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Hello Paul,
Staic runs at the expected RPM, with the flying prop, often draw around 140% of the average flying current.
You can flatten a battery quickly that way.
Unfortunately, testing blind is never a great idea: get an ammeter or Wattmeter and use it during bench tests to avoid frying your new stuff.
I like the clamp-on DC current meter I got at Sears a handful of years back.
take care,
Dean P.
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If you are just trying to run your new battery through a few new cycles (so called break in cycles)
John,
How many times do I have to run or cycle the batteries before I can start to use them for flight?
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John,
How many times do I have to run or cycle the batteries before I can start to use them for flight?
I don't know if there is a set number (some people don't bother to cycle them at ALL). I usually do 5 cycles of charge to full and then return to storage level.
Others will no doubt chime in with what they do or don't do!! ;D