Rv7garage

My Feedback: (10)

I'm getting close to finishing a 1/5 Cub, and have been considering using an 1100 mAh LiFE pack as the onboard power source. My Tx has a "servo test" function, where it will move all the servos through thier full travel. I ran this for 1/2 an hour, twice, and both times put approximately 250 mA back into the pack when charging.

I guess what I'm really trying to say is: I have never used a Lithium chemistry pack as a dedicated receiver power supply. Can I trust this pack? From what testing I have done, it looks like I should safely be able to get 3 flights out of this pack before recharging- does this sound right?


Also, any additional advice on the use of onboard LiFe packs would be appreciated. Thanks!

Goldenduff

I am no expert but the receiver and servos will use more mah when in flight. However 3 flights seems about right.<div>
</div><div>You cannot measure voltage to check life.</div><div>
</div><div>I would fly once then recharge to see how much you've used. If its a maiden you may only want one flight before adjusting servo rod lengths etc </div>

KW_Counter

Your test is semi-valid.
As Dope Fiend stated, you will use more power in flight.
This is due to the wind resistance and engine vibrations.
I assume this is just a receiver/servo pack.
You should get many flights on an 1100 pack.
Keep an eye on the voltage with a loading meter.
Remember, LiFe batteries drop quickly when you
as you get nearer their nominal voltage.

Good Luck,
KW_Counter

tomfiorentino

ill agree with that and add that if you use a voltmagic or similar on board voltage monitoring device its really compliments and adds to the management of life systems in my opinion. When you swash both sticks simultaneously, the rapid change in direction of all servos simulates flight loads. When you do that with the voltmagic on board, any slight and momentary voltage dip will be picked up as voltage is sampled thousands of times per second.

Outside of that Goldenduff is giving you good advice especially with a new airframe. Once you get used to how to manage life batteries...by basically throwing out almost everything you used to do with your airborne packs, you will never go back. They are absolutely wonderful. I have said it before, best thing that happened to the hobby next to 2.4 systems.

Good luck with your bird...have fun with it!

Tom

P-40 DRIVER

Assuming your using standard servos and you don't stay up all day, you will use about 50 to 100 mil amps per flight as I have observed personally. LIFE batteries work great if you treat them properly. There is a big difference between genuine A123 cells and a Hobbico LIFE battery as far as how much abuse they will take though. Do some research and avoid the stupid mistakes people make.

Goldenduff

50-100mah per flight? Seems a little conservative?

tomfiorentino

50cc Extra with 6 high torque digitals and ignition: 570mah per flight.
Tiger 60 with 5 standard digitals: 75mah per flight.
Kadet 40 trainer with 5 JR sport servos: 25mah per flight.

Plus minus flying, number of servos style etc. etc. results will vary slightly.

Tom

Goldenduff

Fair enough! Good info, thanks