I have been flying the s800 on 2 x 5800 turnigy packs and have been only getting around a 5 minute flight time with the gh3. I have the iosd and zenmuse also running on the same batteries. I see people getting like 9 minute flight times. Is there a reason for this or an adjustment I can make? The only thing I am planning on doing is going to a 16,000 mah battery. Any ideas?
S800 EVO Short flight times!?!?
- Thread starter Matto822
- Start date
Benjamin Kenobi
Easy? You call that easy?
It just sounds like your low voltage settings are too high. I use 10,000mah and get ten minutes with a similar setup. Set your low voltage really low for emergencies and use a timer to time your flights. I have my first protection at 21.8v (I think). I like my lipos to be around 3.8v per cell when I land, or at least no lower than 3.75v. The voltage does drop in flight but they bounce back when you land. As long as the drop isn't too much.
Also, new lipos take a bit of breaking in. Treat them nice the first ten flights.
Also, new lipos take a bit of breaking in. Treat them nice the first ten flights.
Benjamin Kenobi
Easy? You call that easy?
Agreed!
And how old are the lipos?
Try setting your first level low voltage to 21.8, same with your alarm.
Lipos are new I have these for the time being until I can get the big 16,000 MAH batteries. So today I did a flight alert preset at 6 cell I land will in flight at 21.9 volts when I land it goes from 20 percent capacity up to 50 percent but to check it I take off again and it drops way down. I am assuming that is the load. What gets me though is when I fly my phantom and the red light hits I land take the batter out and it reads 20 percent those batteries dont go back up like the big ones. I did notice something today I have never paid attention to and that is the "P" rating in the battery. I have 1p rating would a 2p rating give more or less flight time I still dont understand the P rating although I do know it has to do with how they are wired. With these batteries I am getting 5 minutes flight time fully loaded with GH3.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=20639
Would you recommend a different battery?
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=20639
Would you recommend a different battery?
How do you know you are at 20 percent capacity? From the voltage? That's a really bad way to measure capacity.
As I've asked before, how many mAh are you putting back in to your batteries with your charger? That will tell you how much you have used. The voltage isn't a good indication as different batteries behave in different ways.
Ignore the voltage. Just fly for say 5 minutes, land, charge your batteries and see how much you are putting back. Then fly for 6 minutes land and charge etc etc until you are putting back about 80% of the capacity of the batteries. Then you have your approximate max flight time. From then on, just set a timer for your flights. Keep an eye on voltage still because it's a good indication of the health of the battery.
As I've asked before, how many mAh are you putting back in to your batteries with your charger? That will tell you how much you have used. The voltage isn't a good indication as different batteries behave in different ways.
Ignore the voltage. Just fly for say 5 minutes, land, charge your batteries and see how much you are putting back. Then fly for 6 minutes land and charge etc etc until you are putting back about 80% of the capacity of the batteries. Then you have your approximate max flight time. From then on, just set a timer for your flights. Keep an eye on voltage still because it's a good indication of the health of the battery.
Benjamin Kenobi
Easy? You call that easy?
What Rilot said! That's how you do it. Mah not voltage. New lipos voltage will drop during the first few flights. Just have short flight times to begin with.
The P rating is not a rating. P means parallel. So it's basically 6 cells in series providing one parallel lipo. Don't worry about it.
Now the C rating is important! I like 40C and up. C is the discharge rating. Multis don't really use that much amperage but a high C rating ensures you are working well below the maximum of the lipo which means longer life cycles.
What is the C rating of your lipos?
Adding a higher mah lipo won't necessarily give you longer flight times as the pay off is more weight. My sweet spot is 10,000mah for the S800. Adding more mah, and thus weight (unless you use maxamps that are lighter and higher capacity I think) I don't see an increase in flight times.
Voltage varies, that's how it is. The mah your putting back in is the key thing to take away from these replies. Fly for five minutes and charge your lipos and check how much mah goes back in. With 5800mah lipos you shouldn't put back in more than 4640mah (20% rule). I suspect you will find you're putting back in half that.
Thats guys. I am only putting 2220 to 2400 mah back in which is half. I have the the little eos hand battery voltage meter that gives u a percentage reading when u hook up to the balance ports and at 21.9 volts I would land but it would say I still have 50 percent more battery so I keep it hooked up to the battery brought it to a hover and saw it goes back down to 18 percent battery but I am assuming I shouldn't be paying attention to that even if its getting low during flight. Cause I land it bounses back to 50 percent with no load and I charge them and it only takes 2200 mah.
Benjamin Kenobi
Easy? You call that easy?
For new lipos this is normal. A few more short flights and they'll hold their charge a little better. When mine get to 21.9v they usually stay like this for a couple of minutes then drop to 21.8v. Then it's time to land in my opinion, but I could go a little longer as I leave 30% in my lipos. New lipos under load do drop quicker, but not dangerously low. 21.3v would be quite low in my opinion. Dangerously low would be 20v.
It only takes one cell to drop below 3.2v to cause a problem and your voltage monitoring takes an average hence why we leave a large overhead. 21.8v makes 3.6v per cell (under load) which should bounce back to 22.6v or more.
These are my own general guidelines and not a written rule.
It only takes one cell to drop below 3.2v to cause a problem and your voltage monitoring takes an average hence why we leave a large overhead. 21.8v makes 3.6v per cell (under load) which should bounce back to 22.6v or more.
These are my own general guidelines and not a written rule.
Ben, what would u recommend me to set the voltage monitor 1 and 2 in for A2 software?
Will do. Are all new batteries going to be this cycle and if so about how many cycles until they are fairly consistent?
Benjamin Kenobi
Easy? You call that easy?
Once again Rilot 'said it how it is'.
I cycle mine 10 times before I let them rip and consider them flight ready. I also charge and discharge via the charger 3 times from new to check them as they may have been in storage at the shop for a while.
A good 1st level is 21.8v. Second level ummm, 21v?
Cool?
I cycle mine 10 times before I let them rip and consider them flight ready. I also charge and discharge via the charger 3 times from new to check them as they may have been in storage at the shop for a while.
A good 1st level is 21.8v. Second level ummm, 21v?
Cool?
Droider
Drone Enthusiast
Voltage drop is a big factor here. You need to see what the voltage drop is from a fresh pack. So have you got telemetry? Resistance through the whole system is a contributing factor. To know the voltage drop from start up to take of is key. Cheap packs have higher resistances when trying to delver the power, its like kinking a hosepipe. If your voltage recovers quickly after landing then your packs are poor quality I have seen zippys with 1.5v drop. I use Desire Power and only see between .6/.7 of a volt drop. I have GensAce that are about .9/1 volt.
Test your zippys. they are ok on smaller craft not needing so much drawbut on the bigger craft they just dont cut it.
Dave
Test your zippys. they are ok on smaller craft not needing so much drawbut on the bigger craft they just dont cut it.
Dave
Benjamin Kenobi
Easy? You call that easy?
Aye to that.
I use, and have only used, GenAce 40C 5000mah 6S lipos on my S800 so can only speak from experience with those. They do have a low voltage drop as Dave said (less than a volt?) and a less than 2milliohm internal resistance, which is probably why they are so expensive (I have 10 at £100 each, £1000). Naturally I'm very careful with all of them!
Just fly conservatively for short times and get a feel for them.
I use, and have only used, GenAce 40C 5000mah 6S lipos on my S800 so can only speak from experience with those. They do have a low voltage drop as Dave said (less than a volt?) and a less than 2milliohm internal resistance, which is probably why they are so expensive (I have 10 at £100 each, £1000). Naturally I'm very careful with all of them!
Just fly conservatively for short times and get a feel for them.
Not sure I would agree or recommend this. What happens if one lipo fails? Your flight time is going to be halved and if you have no way of monitoring the voltage, the copter is likely to just drop out of the sky after half the normal flight time.
Be very weary of relying solely on flight times and ignoring voltage monitoring; a recipe for disater imho.
Silverburn
Member
Ambient temperature is also a problem.
I have a maxamps 10,900 6S, and I get 60% of the flight time in winter (-5'c to 5'c) that I do in the summer (25-30'c). Lipo's don't like the cold.
Running in new cells at 0'c will display the symptoms you are describing.
I have a maxamps 10,900 6S, and I get 60% of the flight time in winter (-5'c to 5'c) that I do in the summer (25-30'c). Lipo's don't like the cold.
Running in new cells at 0'c will display the symptoms you are describing.
He is talking about in th a2 software. I always run iosd and would never fly without a way to monitor. As for temp not a problemin sunny san Diego lol