Originally Posted by Redfisher

Not sure if it makes a difference but I only fly once a day and do not recharge until the next day with my AC usb port at 300ma. (45 min)

Wow you fly it only ONCE per day! I don't know if I could handle that!

Anyway, I'll be doing flight 40 in the next 2 minutes or so.

Cheers,
Ed

Well I must report that flight #40 was cut short. I went ahead, and had the S107 take off from the top of the book case, and mainly kept flying (mostly hovering with some corrections) within a 4 foot square area of airspace to see how long it could stay in the air before it would start to lose power.

At right around 2 minutes, and 25 seconds, it started to make that sound that tells me it's about to lose power, and altitude. I will correct myself in that the noise is not a "whoosh" but more of a high pitched whine, albeit at a low volume.

I landed the S107 on my hand. Then, I turned it off for a few seconds, reinitialized it, and took off from the bookcase again, but in a few seconds, it started to do the same thing, and lose altitude. That time, I just let it land on the floor in front of me.

Does this sound like a bad battery? Someone mentioned an "under voltage cutoff", which I wonder if that exists in the S107's circuitry.

I now know that if I fly it with frequent take offs, and landings in between, this won't happen. It's almost like the battery can't take a constant, non stop drain for much more than 2 minutes.

What do you all think?

Cheers,
Ed

Sounds like the battery to me, Its not holding voltage under load and its hitting the cutoff.

I think its a battery issue.
The battery has a tiny circuit protection board on it that I suspect controls low voltage protection as well as charging protection.
I'm no expert on Lipo batteries however and its just my gut feel.

I suspect the tiny PCB is 50% of the cost of the copter.

I have never seen SMT devices that small on anything else, and I've assembled F14 avionics.

I guess the general consensus is that the battery could be the problem. Thanks guys!

Flight #41 was fun. I flew the S107 for over 12 minutes by letting it "rest" for 10-15 seconds in between actual time in the air. I didn't allow it to be airborne for no more than 30-45 seconds at the most in between landings.

I realize this may be "cheating" a bit because it's not a non stop flying session, but hey, the purpose is to have fun, right?! This avoids that annoying power loss at the 2 and a half minute mark that effectively terminates the session.

On another note, my flying skills are improving by flying in this fashion. Nothing wrong with that.

I think I will order those batteries that "jtravel" pointed out on eBay.

Cheers,
Ed

Originally Posted by Redfisher

Hey if it works its all good, Another Ontario guy I see.

Hi Red. Yep in Strathroy. BTW, you can get these at Giant Tiger.

Really!!! I was just at GT last week, didn't go down the toy section though. I will go check it out tomorrow on my way to the gym.

Hmm, if the Firebird has the original electronics board I suppose I'll go with that. I don't think this is going to be my biggest investment, anyway . I'd like to build these tiny things (and tinier!) so... thank you and happy flying!

Originally Posted by edwong3

I flew the S107 for over 12 minutes by letting it "rest" for 10-15 seconds in between actual time in the air. I didn't allow it to be airborne for no more than 30-45 seconds at the most in between landings.
Ed

Did alittle research on Lipo Batteries and the tiny board on the battery is
a built-in Low-High voltage protector
circuit which constantly monitors the voltage of each cell during charge-discharge.
This prevents the battery for being over charged above 4.2 volts and possibly exploding.
It also monitors the Drain during use and can reduce the current drain if the voltage drops to 3 volts This is to protect the battery from over discharge and permanent damaged.

When your flying all out your really sucking the current from that battery and once it can't supply that high rate of current drain the voltage starts dropping until the protection kicks in and reduces output current even more.
The board on the battery can fail causing it to trigger LVC prematurely and reduce power even when the battery actually has a healthy charge.
The high voltage circuit can fail allowing your charger to overcharge it and cause permanent damage to it.
So Did the LIPO cell actually fail or is it the electronic protection circuit board on the battery that failed?

The battery that came with my skylark didn't work right out of the box.
2 min flight times that quickly went down to 30 sec after only a couple charges. last flight I drained it and didn't charge it.
Took a meter to the output and read 3.4v This is the unloaded voltage and would drop under load likely triggering LVC protection.
I took the board off and measured 3.8 volts directly on the battery terminal.
My conclusion was the battery was good but the protection circuit was shutting it down by going into LVC prematurely.

We had 2 Syma S107's that had a wire break off of the front motor, right where the wire enter the motor. The wire could not be easily reconnected.

I took the REAR motor from 1 bird, and installed it into the FRONT of the other bird, reversing the polarity on the 2 wires when I soldered them to the circuitboard.

WORKS FINE.

The 2 motors (front & rear) are the same, they just have different color leads. You can substitute the front or rear motors, you simply have to make sure you get the polarity correct as they rotate in opposite directions.

Now, why the wires broke, see my next post!!!!!!!

The upper left metal frame member has 2 tabs on it which hang over the 2 motors, to help hold them in place. If the motors rotate in place the motor wires can hit the tabs and the wires can break off the motors.

Now, we REALLY abuse our birds, they undergo far more physical abuse than they should.... so where we have had our motors rotate into the tabs, you may not.

Keep an eye on the motors, make sure the motor leads are towards the front & rear, and NOT left & right. The frame tabs can sever them!!!

The one S107 we had that displayed the loss of power behavior was not the battery; when swapped out with a new one (along with the PCB protection circuit board) it displayed the same symptom right away. The assumption was the main board caused the issue but never had to verify that as the supplier provided an exchange.

Replacement main boards can be had for $6 or so on some sites (but I have seen as much as $18 as well) but you still have to provide your labor and soldering skills to accomplish the repair (assuming that is the issue which seems inconclusive) - and with KB's picture gallery should make that possible.

The 3 S107s and one Firebird (in my squadron) all fly pretty well so far but all have distinct traits.

My little red S107 just flew it's 45th flight outside in the cool of the night. It's almost surreal to see that little flashing light in the dark. We do have street lamps across the street.

My total time outside lasted about 8 minutes as I did my new intermittent technique of flying for 30-60 seconds and putting her down for a few seconds, and take off again.

We've been having much nicer temperatures here in Central Florida, and that made it all the more pleasant.

I'm now a "fly by night" operator!

Cheers, Ed

Well hopefully, my Rev 3 board is OK. I did order two 3.7V 150 mAH for under $5.00 shipped, on eBay.

I'm willing to go that far if it restores my 107's flying duration, but if it turns out to be the board, too bad. I can just keep flying in intervals to prevent the premature power loss until the thing just gives up completely.

Happy flying,
Ed

Originally Posted by Duck05

The one S107 we had that displayed the loss of power behavior was not the battery; when swapped out with a new one (along with the PCB protection circuit board) it displayed the same symptom right away. The assumption was the main board caused the issue but never had to verify that as the supplier provided an exchange.

Replacement main boards can be had for $6 or so on some sites (but I have seen as much as $18 as well) but you still have to provide your labor and soldering skills to accomplish the repair (assuming that is the issue which seems inconclusive) - and with KB's picture gallery should make that possible.

The 3 S107s and one Firebird (in my squadron) all fly pretty well so far but all have distinct traits.