fly times

[spankey]

hi all,

what sort of flying times can I expect from the Titan E325 with a plus 3S1P 2200mAh 25C LiPo XP, this is my fist heli and still waiting for it to arrive, so remember I wont be pushing things yet :)

[mkoutnik]

You'll first want to cycle your new battery 5-10 times only running it for about 3 minutes, let it cool, charge/balance, repeat. This will prevent any battery puffing that may ocuur if you push it too hard right away.

After break-in, I use the rule of thumb to run the battery down to about 80% of its original capacity (this prevents any possibility of discharging the battery too low)...e.g. 11.1 V, 2200 mAh, 3S battery is made up of 3 cells wired in series and will charge up to about 12.6 V. So, 12.6 x 80% = 10.08 V. You definitely don't want to run the cells below 3.0 V per cell or 9.0 V total! Be sure to set your ESC for the proper cut off voltage.

This should help...http://thunderpowerrc.com/PDF/THPSafetyWarnings.pdf

With all of that said, you can probably expect 6-7 minutes of good flying time per battery. Of course, this also depends on pinion/gear ratio used, and type of flying. I use the stock 13-tooth pinion on my mini titan.

[henrik04]

As it is your first heli, I would definitely add a battery Lipo warning of some sort.

Timer don't really help as depending of the kind of flying, flying time change drastically.

As you'll try to concentrate on many other thing while learning, battery will be completely out of your mind while successfully hovering.

In turn you'll probably completely forget the "battery 80% rules" and damaged your Lipo.

If you go for it, insure that you buy a Lipo warning which check each cell and not the "el-chippo" which looks only at the total battery voltage.

I get 10 minutes easy with 2,500 mAH in hovering and circuit flying.

Happy flying.

[cmb2003svt]

henrik04,
Do you mean something like below? I only have one of those annoying refrigerator voltage detector. It makes perfect since about monitoring each cell. I am in the hover and circuit stages of learning and would like to concentrate more on flying than "AM i at the 80% mark yet?"

http://www.helidirect.com/product_info.php?cPath=31&products_id=4535

[henrik04]

Yep this one looks very good! (I dign't use it personally but looks ok while looking at the short video)

The only thing I'm not really sure is what exactly do they mean by "soft cut off?" (Hopefully they won't turn off completely the motor..

Looks simple and user friendly.

Happy flying.

[comeflywithme]

Hi,

I think there is a little bit of confusion over the whole 80% rule as this refers to capacity and not voltage. What this means is that with a 2200mah lipo, it is wise no to discharge more than 2200x0.8= 1760mah. The relationship of voltage vs capacity is key here as and it follows 3 stages (often seen illustrates on Graphs as a type of 'S' curve on its side):

1. Rapid drop of voltage from 4.2V/cell down to the nominal 3.7V/cell over the first <5% of the lipos capacity (first 10secs or so of flight)

2. Very slow decrease of Voltage over the following 85-90% of the capacity (voltage will drop depending on the loading on the motor but the average should undergo very little decrease)

3. Rapid drop of Voltage from nominal ~3.7V/cell down to 0V/cell over the final 5% of capacity.

It is this 3'd stage that you want to avoid coming into. If a lipo is discharged untill a loss of power is detected then its very likely that you are already entering this final stage and the lipo will suffer. Thats where the 80% rule comes in as it prevents us from enetering this final stage of voltage drop.

Personally I only use my esc's voltage cut of set to normal and limit my timer to 5mins. I fly in idle up 3000rpm and 3D/Aerobatics for the entire duration and it takes out about 1500mah. Therefore no matter what your level of flying is, you wont risk over discharging the lipo if you set it to 5-6mins. Just set the timer, then concentrate on flying and land when it beeps - simple :-).

Sorry if I'm stating the plain obvious but I thought it might be useful to some beginners.

Good luck with your first flights!

[henrik04]

I agree completely with your statement (S curve).
However as you mentioned very justly the third stage, you do not want to have one unbalanced cell entering this stage on its own.
Using the ESC alone which look at the total voltage may miss completely a single unbalanced cell. In turn when your ESC will give you the 'global warning' this unbalanced cell will be discharged beyond normal usage.

So using a Lipo warning looking at all the cells works as per your 'ESC warning' but on a cell by cell basis.

Happy flying

[EricW]

Mkoutnik gives a good advice Imo.
Best thing is to time your flights (on the Tx), and always monitor how much you charge back in the pack and measure the cell voltages.
I never use the cutoff function on the Ace ESC, it cuts the head speed drastically (pulsing) and that can be annoying in some situations, especially when your not experienced yet.
With my current flight style I can fly 6:30 (2800-2900 governor head speed) and charge back 1750 Mah (3,7V p/cell) of 2200 Mah total.
Brake-in new batteries by hovering 4-5 minutes, a couple of times.

Eric