H Battery Bull S**T

DroneClone · Jun 8, 2016

Couple things, and yes I know how to break a Lipo in !. We have all been back and forth on the "Supposed" correct safe voltage to land at approximately 14.7 v, but something is not correct, or am I seeing things wrong ?
First off I charge 100% to 16.8v, If I fly at hover/or not, down to our supposed 14.7v, I still have according to the 4 green battery level bars 2 bars left= 50% charge left (Yuneec says the bars are accurate?) And then they charge back up to 100% in about one hours, not the 2.5 hours, so that confirms that I am only using about half the battery available.
I do realize that with Lipo's that there is a fast drop off in voltage the last 20%, but **** ! I think we could fly down below 14.7v to get a safe full voltage? What do you all think? Stopping at 14 minutes/14.7v is nowhere near the specs listed by Yuneec !

Dezzzy.D · Jun 8, 2016

Faulty battery?

DroneClone · Jun 8, 2016

Dezzzy.D said:
Faulty battery?

Naw, my batteries are fine!, I am just saying we can get more out of them flying than 14.7 volts, if we have decided that that is the sweet spot to fly em too. Cause at 14.7 v i am seeing about 50% left to use

Dragonflyerthom · Jun 8, 2016

DC I'm thinking fly it to 25% and first buzz. Now I wouldn't leave it there for a long time but over night shouldn't hurt. I agree the 4.7per cell is too high. Get the most out of these batteries.

David Wilson · Jun 8, 2016

It has been clearly determined that is is safe to fly down to 14.3, the initial low warning. This should give you 19-20 minutes of flying which is quite good. Call Yuneec if you need to confirm voltage issues.

Marnix Verschraegen · Jun 8, 2016

Normally if you not go under 3.5V in one cell you should not have a problem.
If you go under 3V in one cell you will damage your battery
i always not go under 3.3V on my DIY multicopters, a lot of ESC's are shutting down around 3.2V in one cell (of course you can change this to 3.0V, but that's dangerous). If a ESC shuts down your bird is becoming a brick falling from the sky.

/\/\ax2206

BobW55 · Jun 8, 2016

The other concern I have is just WHAT will the H do when battery level gets critical.
I red some where it will attempt a RTH. But if you are to far out, will it just shut down and crash, or will it descend where it is and attempt to land.
I need a net and some rope, just tether the thing down and let it hover and see what it does. (who would be crazy enough to do that)

Allan · Jun 8, 2016

I was out about 1000 feet when the ST16 started vibrating and said low voltage. Gauge read 14.3 volts. I flew back (took about 1.5 min) and landed, no problems, no rth kicking in, etc.

SnowRaven · Jun 8, 2016

The harder you are on a quality LIPO the shorter its life span will be 3.5 is reasonable

Dragonflyerthom · Jun 8, 2016

Now according to my calculations 25% of a full battery is 1.0375 per cell on a 4 cell battery. Seems low but math is math. That is 4.15 total volts in it. I wonder if there is any damage if it goes this low.

DroneClone · Jun 8, 2016

Dragonflyerthom said:
Now according to my calculations 25% of a full battery is 1.0375 per cell on a 4 cell battery. Seems low but math is math. That is 4.15 total volts in it. I wonder if there is any damage if it goes this low.

DJI's batteries are a higher quality as Smart Batteries and have 10% as "Critical Warning" and 30% as recommended, so what is the verdict?

Unfaix · Jun 8, 2016

Dragonflyerthom said:
Now according to my calculations 25% of a full battery is 1.0375 per cell on a 4 cell battery. Seems low but math is math. That is 4.15 total volts in it. I wonder if there is any damage if it goes this low.

It would actually be 3.15v per cell.

Normally want to fly 80% of your battery, and have 20% left.

So if you have a full 4 cell at 16.8v, times hat by 80% and you'll get 13.44v, which is 80% use with just 20% left.

Same calculations, 4.2v *.8=3.36v

The last 20% of capacity left drops exponentially.

DroneClone · Jun 8, 2016

But many state on here that 14.6 is the "SAFE" voltage, that leaves way to much voltage to be usable in my mind.(After break in). Fly till 1st vibration warning is coming at 14.3 v many state, this is ludicrous !

PRnNJs FINEST · Jun 8, 2016

David Wilson said:
It has been clearly determined that is is safe to fly down to 14.3, the initial low warning. This should give you 19-20 minutes of flying which is quite good. Call Yuneec if you need to confirm voltage issues.

I've flown both of my batteries like this and have not had any issues till this day.

DroneClone · Jun 8, 2016

PRnNJs FINEST said:
I've flown both of my batteries like this and have not had any issues till this day.

Thanks ! PRnNJs, meaning down to first warning or 14.3 v ?

PRnNJs FINEST · Jun 8, 2016

Thats actually when my first warning comes in, right at 14.3v

DroneClone · Jun 8, 2016

Unfaix said:
It would actually be 3.15v per cell.

Normally want to fly 80% of your battery, and have 20% left.

So if you have a full 4 cell at 16.8v, times hat by 80% and you'll get 13.44v, which is 80% use with just 20% left.

Same calculations, 4.2v *.8=3.36v

The last 20% of capacity left drops exponentially.

Don't think it will let us go down that low (13.44v) without warning and then auto land ! Anyone try it ?

Dragonflyerthom · Jun 8, 2016

I just flew mine to the first warning. It was 2 bars I think it was 14 volts then I came home. I'll pay closer attention next time. Way too much fun.giggles

DroneClone · Jun 8, 2016

Dragonflyerthom said:
I just flew mine to the first warning. It was 2 bars I think it was 14 volts then I came home. I'll pay closer attention next time. Way too much fun.giggles

About what I am getting too!