opjose

We've been running Giant Big Stiks as trainers with 3300mAh 3S LiFe Packs driving 7 high torque 13KG servos and one standard standard servo though a voltage regulator. The gas DLE-20 gas engines we use also use 2S 2000LiFe packs to drive the ignition.

On an given training day, each plane sees 20 plus 15 minute flights without recharging, pausing only to refuel.

We used to fly the planes for 24 minutes per flight, but this was tiring out the instructors.

Average current returned to the battery packs is consistently in the 1100mA to 1300mA range for BOTH the electronics and ignitition.

Now we are stepping down from a higher voltage ( a good thing as this is more efficient for a regulator ) than you propose to, but you SHOULD be OK.


That said, to be sure, your best bet is to fly your plane for 15 minutes of hard flying then recharge the packs and see how much you put back in.

Lightspeed1551

My Feedback: (4)

If you are nervous use a 5200mAh fromeco li-ion pack. 6.6oz and none of the dangerous poof and blow that li-po's are famous for.

http://www.fromeco.org/categories/Lithium_Ion

bjr_93tz

Interesting point I discovered was when I was looking into repacking the TX batteries for my 14MZ was one website showed a Fromeco "re-lion" pack (3600mAh form memory?) being used for the cells. The particular cells in that particular pack needed to be charged to 4.3V/cell to get anywhere near the rated capacity as indicated in the manufacturers data sheet for that particular cell and according to the manufacturers discharge data only charging to 4.2V/cell you struggle to get 2/3rd rated capacity.

It was an eye opener to me because unlike li-po's which we charge to 4.2V/cell, I believed all Li-ion cells could only take 4.1V/cell like in my cordless drill. I ended up going for a panasonic cell designed to be charged at 4.2V/cell for the TX battery.

jetmech05

Never take the days of flying without a recharge to heart. Always check your batteries with a loaded voltmeter at the start of the day.
Here's what I do. I'm running 9 servos I know that I can probably get 2 days of flying with a cushion on a charge. Check the batteries with a 1 amp load recharge at 7.1 volts.
now if it's the beginning of the day I'm going to recharge before I fly. But if I check it at the end of the day and I'm at 7.1 I'll fly that last flight but keep it short.... You'll get the hang of it. Once you go gas you never go back.....good luck