How many flights should I be getting out of this RX LIFE Pack?

[Stevin]

I use a 3800mah 6.6 LiFe pack on my velo 50 to power my servos and vbar, it is a hyperion pack how many flights should I be getting before having to charge? I notice after a flight or so it will drop to 6.6 and stay there for a bit. Im wondering how many 7:30 minute flights I can have before charging again

[Lottomunch]

You really need to fly it 2-3 flights and then see what you put back into the pack. Then....at the end of the day...(if you safely think you have room) fly it 4-5 flights and then put it on a discharger and see what you have left in it. That way you're developing REAL confidence in what your pack will give you and how you and your heli use the power.

Just for starters though.....and don't trust these verify it yourself.....I fly aggressive sport wanna be 3D and I use 115-150 mAh on a Trex 550. A buddy flies very aggressive on a 90 and pulls closer to 300 mAh on a flight.

[jdwelch]

Originally Posted by Lottomunch

You really need to fly it 2-3 flights and then see what you put back into the pack. Then....at the end of the day...(if you safely think you have room) fly it 4-5 flights and then put it on a discharger and see what you have left in it.

+1

You cannot depend on a voltage reading on a LiFe pack. Look at the discharge curve for LiFe batteries. They hold their voltage very flat following the initial drop until they are exhausted and then fall off rapidly. Unlike a Lipo, their state of charge cannot be determined by their voltage.

[Down Low]

+1 to all the above. After monitoring my own 2080mah Hyperion LiFe packs I get 4 flights out of one pack and put back about 1700mah. This is on a 600 size FBL nitro with Futaba cyclicks and a JR tail servo and on board glo igniter.

[Adventurer]

Yep, check it out yourself. Different servos pull widely differing amounts of power. My KDS N680 cyclics can suck an 1800 mAh Life pack dry in 4 light sport flights.

I've just changed to Align DS610, but have not flown them yet. I'm hoping that they will use way less power.

Fly one or two flights - recharge and work-out how much was used per flight, work-out how many flights you can get applying the 80% rule. Then add a safety margin on top of that.

Then do a capacity test on your LiFe pack to verify the claimed capacity and repeat this at least once a year and adjust your number of flights accordingly.

I've decided that 3 flights is my limit, so I have 3 main packs, and when they're empty then all the packs get charged. 3 main (parallel) and the LiFe pack on a dedicated charger.