Can We Agree On A Battery Level?

PatR · May 23, 2016

DroneClone said:
What the **** ? ! WHAT ARTICLE ARE YOU TALKING ABOUT? I did not do an article on a ammo can! or anything on discharging in any device. Please get the names right so you can disagree with the right person my friend! LOL I was telling him to call Yuneec or learn on this forum to learn more about the "Yuneec" battery!

The article you quoted from DeMarco. I didn't say you wrote it or approved it, it's just where I first saw the reference. Sorry you took it in a way it wasn't intended.

DroneClone · May 23, 2016

No offence M8, Just the thingy about a ammo can and right above it you started with DroneClone, . If you read it, it sure looks like you are disagreeing with me ! Sorry if I jumped in your face, but I am having a bad drone day ! Mushroom antenna came broken and Yuneec wants me to send the whole **** ST16 in to replace a screw on antenna! Just send me a new screw on and I'll send the broken, it took me 30 minutes to explain the logic and I was speaking to Spock! LOL, Sorry Pat ! Please forgive meee!

Buy the way I do appreciate your information! P.S, I don't even see anything posted about an ammo can? Is it on another post?

deMARCOman · May 23, 2016

DroneClone said:
P.S, I don't even see anything posted about an ammo can? Is it on another post?

@ DroneClone Read the article I posted. That stupid suggestion re: ammo can is in there --->. The Ultimate LiPo Drone Battery Care Guide

PS and thanks for going to distance by gathering Yuneec's battery voltage info. It will help out a lot of people. And maybe save a house or two. lol. Or at least lengthen the life of a few batteries.

KBflyer · May 23, 2016

HarveyC · May 23, 2016

DC, did Yuneed tell you anything yet about battery voltage levels?
1. From what I've seen, ST16 gives first low battery warning when it shows 14.3v (once motors turned off, ST16 shows reading of 14.6v), this seems less 10% remaining and damages cells?
2. At what level does ST16 give second warning?
3. Can we adjust these level settings?

Tecneek · May 24, 2016

DroneClone said:
Have we flown and studied enough to come to agreement as to a safe battery level to land at? Since we do not have flight battery %'s! lets's say 14 V? Any comments!

Maybe it would always be different based on the distance the bird is away..

Tecneek · May 24, 2016

Tecneek said:
Maybe it would always be different based on the distance the bird is away..

I would question what is half of the capacity, and so if I am 2000 feet out I figure it would take at least the other half to get me back.. Traveling at the same speed

PatR · May 24, 2016

DroneClone said:
No offence M8, Just the thingy about a ammo can and right above it you started with DroneClone, . If you read it, it sure looks like you are disagreeing with me ! Sorry if I jumped in your face, but I am having a bad drone day ! Mushroom antenna came broken and Yuneec wants me to send the whole **** ST16 in to replace a screw on antenna! Just send me a new screw on and I'll send the broken, it took me 30 minutes to explain the logic and I was speaking to Spock! LOL, Sorry Pat ! Please forgive meee! Buy the way I do appreciate your information! P.S, I don't even see anything posted about an ammo can? Is it on another post?

No worries mate, I could have written that better as well. The ammo can thing was in the linked article from DeMarco.

PatR · May 24, 2016

HarveyC said:
DC, did Yuneed tell you anything yet about battery voltage levels?
1. From what I've seen, ST16 gives first low battery warning when it shows 14.3v (once motors turned off, ST16 shows reading of 14.6v), this seems less 10% remaining and damages cells?
2. At what level does ST16 give second warning?
3. Can we adjust these level settings?

Harvey,

The table that Typhoon Charlie posted on page 1 is a great piece of information to have and follow. Because winds change and how we fly the aircraft changes battery use time is not predictable. If we fly the same way every time we can, over a series of flights, develop a rough idea of how long we can fly on a charge. But that will always be an estimate, and estimates should always have some buffer built into them to stay on the safe side. The low voltage values Yuneec is providing will be quite good for them. They'll sell a lot more parts, aircraft, and batteries if people run their batteries down that low all the time. All lipo's work the same where voltage is concerned. We are not buying some newly developed super lipo's stuffed into a Yuneec plastic shell.

Personally, my voltage floor will be 15v, at which point I'll have already landed and be pushing the power off button. Keeping my equipment is more important to me than a couple minutes of flight time. I handle all my batteries the same way, and it's paid off in long battery life, lots of flights, and no crashed aircraft because of low batteries.

HarveyC · May 24, 2016

Pat, don't really understand why you quoted my post when you didn't answer anything in that post.

I'm thinking of using 14.7v as my threshold with battery voltage returning to 14.9-15.0v once the motors are turned off. I don't think at the present time we can adjust the alarm settings, however, so it's just something to keep track of. The only time I've dropped below 14.7 was when I hovered to test when the alarm would go off.

MDHughes · May 25, 2016

So, Y'all know about the 10 - 10 rule for new LiPo batteries right?
(first ten flights, only fly for 10 minutes)
It gradually breaks in new batteries and makes 'em last longer!

I acknowledge that there is some controversy on this subject, but I figure it can't hurt and may also alert you to a bad battery before it causes a crash...

PatR · May 25, 2016

I use something similar when breaking in a new battery.

Harvey,
Up to now Yuneec hasn't permitted much adjustment of things like alarm settings and RTH altitudes. Without having the H in my hands, that's supposed to be tomorrow, my guess is nothing has changed in that regard. What I intended to reference from your post was the Yuneec battery voltage levels. 14.6/14.3, under load, are a probably a bit lower on a per cell basis than we should take these batteries. At 14.3v that's 3.575v/cell with 14.6 at 3.65v/cell. Both are under the normally recognized safe 3.7v/cell floor. Sure, we can go below that, but how many times before accumulated damage from the previous dips combine to bite us on the butt?

HarveyC · May 25, 2016

PatR said:
I use something similar when breaking in a new battery.

Harvey,
Up to now Yuneec hasn't permitted much adjustment of things like alarm settings and RTH altitudes. Without having the H in my hands, that's supposed to be tomorrow, my guess is nothing has changed in that regard. What I intended to reference from your post was the Yuneec battery voltage levels. 14.6/14.3, under load, are a probably a bit lower on a per cell basis than we should take these batteries. At 14.3v that's 3.575v/cell with 14.6 at 3.65v/cell. Both are under the normally recognized safe 3.7v/cell floor. Sure, we can go below that, but how many times before accumulated damage from the previous dips combine to bite us on the butt?

I don't know but probably at least once. My test was to see when the alarm would go off and I think most of us now know because of that test that we should be watching voltage level on the monitor rather than wait for the alarm. I brought that up with Yuneec today and the support staff did not seem to understand there was a problem with voltage dropping down to 14.3/14.6. I wish I had tested that drained battery on my multimeter right after the flight. I don't know that my multimeter is accurate but I believe it is fairly accurate and immediately after charging a battery I usually see a reading of something like 16.72 but as soon as it is put into the H and the monitor is turn on and the H is turned on the display shows 16.6. So maybe (just maybe) battery voltage after the alarm could be closer to 14.7 which is getting closer.

DroneClone · May 25, 2016

I will, as stated before, be on the ground or fairly close to landing at 14.9-15 v, till Yuneec can give a intelligent, warranty honoring landing voltage!

HarveyC · May 25, 2016

Today when coming back home from a distance test with my new FPVLR antenna I had a strong headwind (20-22 MPH) and my low battery warning came on while I was still about 2,000' from home. I checked and the display showed voltage at 14.6v which is odd because the other day the warning came on while hovering near home at 14.3v. I was not in a good landing location so came down low and continued flying home at a slower speed (something like 6-7 MPH, if I recall correctly), while continually watching the voltage reading. Oddly, the voltage did not drop any further than 14.6v over the next few minutes and I then landed about 100' from where I was standing as I didn't want to use battery power to climb over some trees between me and that landing spot. After I shut down the motors voltage reading was 14.9V which I think is an okay level for battery life.

Based on this experience, it seems that the low battery warning will come on at a higher voltage reading when flying hard vs. hovering.

I chatted with Tim at Yuneec about battery voltage readings earlier. I'll address some things he shared (all consistently in 4 cells so that it's clearer):
1. Should not store battery fully charged for more than 72 hours. Best to store at 15.4v.
2. Over discharging repeated to 13.6v-14.0v will decrease battery life
3. Operating drone and draining battery down to 14.6v "is not bad" but 15.2v "is preferred"

Since there is some voltage sag with motors running, I think I'll target somewhere around 14.7v-14.9v with motors running when landing. Not advice for others, make your own judgement.call on this.

DroneClone · May 25, 2016

HarveyC said:
Today when coming back home from a distance test with my new FPVLR antenna I had a strong headwind (20-22 MPH) and my low battery warning came on while I was still about 2,000' from home. I checked and the display showed voltage at 14.6v which is odd because the other day the warning came on while hovering near home at 14.3v. I was not in a good landing location so came down low and continued flying home at a slower speed (something like 6-7 MPH, if I recall correctly), while continually watching the voltage reading. Oddly, the voltage did not drop any further than 14.6v over the next few minutes and I then landed about 100' from where I was standing as I didn't want to use battery power to climb over some trees between me and that landing spot. After I shut down the motors voltage reading was 14.9V which I think is an okay level for battery life.

Based on this experience, it seems that the low battery warning will come on at a higher voltage reading when flying hard vs. hovering.

I chatted with Tim at Yuneec about battery voltage readings earlier. I'll address some things he shared (all consistently in 4 cells so that it's clearer):
1. Should not store battery fully charged for more than 72 hours. Best to store at 15.4v.
2. Over discharging repeated to 13.6v-14.0v will decrease battery life
3. Operating drone and draining battery down to 14.6v "is not bad" but 15.2v "is preferred"

Since there is some voltage sag with motors running, I think I'll target somewhere around 14.7v-14.9v with motors running when landing. Not advice for others, make your own judgement.call on this.

Good Job !

Typhoon Charlie · May 25, 2016

The typical Lipo has a discharge curve similar to the graph bellow. As you can see when the voltage gets to a certain level the drop off is quite steep. This means that you can find yourself on the ground before you even know it. Discharging a Lipo to 3.5V per cell is not really bad, just as long as you let it get to room temperature before recharging. The worst you can do to a Lipo is charging it while hot, charging at a rate higher than 1C ( 1X rated discharge capacity) and drawing more than it's maximum discharge rate longer than the rated time. Now, I have stored Lipos fully charged for months at a time without adverse effect. I never storage charge my Lipos, I regularly discharge them to their minimum and some times bellow. In a few occasions, I have run a pack flat which I have brought back to life by doing NiCad charge until the voltage is above 3V then switching to Lipo balance.Most Lipo cgargers will not charge if cells are bellow 3V. I don't know the quality of the H batteries so I can't comment,I am basing my experience with Venom battery brand which are very tough and take abuse well. So , what you need to do is find the curve on your Lipos by trial and error so that you know exactly when to land and still get as much out of them as you can. Keep in mind that Yuneec does not make batteries, they purchase them from vendors, put them in their case and brand them. So there is no way to know where they come from and how consistent they are, so not all your batteries are going to behave the same. Hope this helps some.

HarveyC · May 25, 2016

Good info Charlie, thanks

GlenT · May 26, 2016

Personally, I would be on the ground at 14Volts (3.5 Volts/cell) This is an "under load" measurement. So obviously that would climb without load.
I have always used voltages on my OSD's rather than percentage, so for my current 6s packs I make sure I'm on the ground at no lower than 21Volts.
Of course, every pack is different and these proprietary units for the H have little real world use yet. C rating effects voltage readings under load. Does anyone know the C rating of these packs yet?