High-wind quick battery drain
- Thread starter KEITH KUHN
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Wouldn't think so Keith - what kind of time are you getting with that battery in normal conditions?
my X very when I usually don't let it get to the low battery warning indicator in good weather usually I would say 10 minutes 12 minutes I'm bringing it back back home.
Yeah something is wrong with that pack if it only does 3 mins. I fly in high wind all the time, and it makes about 2 minutes difference to me in most flights; that is to say I am still getting 12-14 mins even when it's very windy up high as opposed to more like 16 mins if it's calm. In fact I have just sent back a Morpilot battery pack that was only giving me 7 minutes, wind or not, so only 3 minutes suggests something is very wrong.
@KEITH KUHN can you check the internal resistance levels on that battery?
Also, I would do another test flight... nothing crazy... some circles 10 foot altitude... maybe 25 feet distance. Watch the voltage on the ST-16. Does it drop steadily through the flight? Or does the voltage drop quickly, early in the flight... and then level out at a reasonable rate?
I have a battery like that for the H. In my case, one cell had a significantly higher IR in one cell... and in flight, the voltage would drop from the normal ≈16.4V starting voltage to 15.1V in under 30 seconds... then run down normally for the 5-7 minutes it would last, until first warning.
I ended up using that battery exclusively for non-flight operations... FW upgrades, calibrations, letting the bird sit to update the GPS almanac, etc. For non-flight, it's fine... I just don't trust it in the air anymore.
Also, I would do another test flight... nothing crazy... some circles 10 foot altitude... maybe 25 feet distance. Watch the voltage on the ST-16. Does it drop steadily through the flight? Or does the voltage drop quickly, early in the flight... and then level out at a reasonable rate?
I have a battery like that for the H. In my case, one cell had a significantly higher IR in one cell... and in flight, the voltage would drop from the normal ≈16.4V starting voltage to 15.1V in under 30 seconds... then run down normally for the 5-7 minutes it would last, until first warning.
I ended up using that battery exclusively for non-flight operations... FW upgrades, calibrations, letting the bird sit to update the GPS almanac, etc. For non-flight, it's fine... I just don't trust it in the air anymore.
PatR
Premium Pilot
If the winds are high enough and you’re flying full power into the wind, it’s certainly possible. I’ve never had it happen that quick, 6 or 7 minutes the fastest in near 30mph winds, but depending on how you treat your batteries it’s possible. The higher the wind the harder the system has to work, the harder it works the more current it consumes. Just like muscles and calories, gas engines and fuel consumption at high speed.
I am not sure how old this battery is either. I don't normally fly in high winds at all. so I hit return home immediately and it is always great to have a nice flight home and Landing. thanks for your reply I will keep a close eye on my batteries even during good weather flight.
Keith Kuhn
thanks Pat I was just curious I was just telling somebody I'm not sure how old my battery is but I sure will be keeping a close eye on it. I know it is a lot of strain on it just like you say using more power or muscle. I put the batteries on my voltmeter when I got them home they read 15.8
PatR
Premium Pilot
A continuous high current load will pull a battery down quickly on the front end and show a significant bounce back after shut down. Post flight voltage is a poor gauge of condition. Cell internal resistance is a much better means of determining battery state. The higher the IR, the poorer a battery will perform.
Hi all.
Flew my H today for the first time in a little while and had a bit of a fright. I had switched on the H and let it sit Idle for appx 14min, took it out for a quick shoot of some building work some 390m away. Within 3.5min of lifting off I got a battery warning fly below 60 etc. I hit RTH and watched the battery metre empty with a red outline and was anticipating it dropping from the sky. Looking at the footage it came back a high speed, I cancelled RTH as soon as it was over our works yard and hand caught it.
I kept my batteries at appx 15.4v, although this was achieved through using them to run down to this voltage, don't have a charger that can do a storage cycle. I have checked on the voltages in the H periodically.
Conditions of todays flight;
14c/57f
13mph Wind
bright
in 4min I went from 15.9v - 14.6v, hit RTH during the 390m return flight the voltage dropped to 13.9v and recovered to 14.6v while descending and finally 15.4v at switch off, 6min after take off.
Letting it idle to start probably didn't help but the voltage dropped so quick, I might recharge it and do some tests. Can't post telem files, extension not allowed.
Flew my H today for the first time in a little while and had a bit of a fright. I had switched on the H and let it sit Idle for appx 14min, took it out for a quick shoot of some building work some 390m away. Within 3.5min of lifting off I got a battery warning fly below 60 etc. I hit RTH and watched the battery metre empty with a red outline and was anticipating it dropping from the sky. Looking at the footage it came back a high speed, I cancelled RTH as soon as it was over our works yard and hand caught it.
I kept my batteries at appx 15.4v, although this was achieved through using them to run down to this voltage, don't have a charger that can do a storage cycle. I have checked on the voltages in the H periodically.
Conditions of todays flight;
14c/57f
13mph Wind
bright
in 4min I went from 15.9v - 14.6v, hit RTH during the 390m return flight the voltage dropped to 13.9v and recovered to 14.6v while descending and finally 15.4v at switch off, 6min after take off.
Letting it idle to start probably didn't help but the voltage dropped so quick, I might recharge it and do some tests. Can't post telem files, extension not allowed.
good observation glad you did all that I look forward to your next test. keep us posted I'm very interested
PatR
Premium Pilot
You did not mention if the battery had been charged prior to the flight. If it had been sitting for a long time and at 15.9v when you chose to use it the battery would not have been at a good state of charge. Your H should have been landed long before the battery reached 13.9v, regardless of where it was. As you mentioned it was an H I’ll assume the batteries may be old and the lack of a good charger has prevented properly maintaining them. Both combine to reduce battery efficient snd functionality.
Good chargers and associated equipment do cost money but people that think they can save a few bucks by not buying one and dealing with their batteries through other methods won’t save any money in the long run. They’ll end up buying new batteries sooner than they would otherwise have or crash their aircraft. At best they will be guessing at the condition their batteries are in and hoping for the best. Neither guessing or hope are things to be relied on.
Just an info thing, that your battery recovered over 1/2v during descent should make you consider internal resistance might increased since you first got the battery. I’ll suggest visiting www.batteryuniversity.com as has been done for others to learn more about the factors that affect battery performance, and how IR reduces battery efficiency.
Good chargers and associated equipment do cost money but people that think they can save a few bucks by not buying one and dealing with their batteries through other methods won’t save any money in the long run. They’ll end up buying new batteries sooner than they would otherwise have or crash their aircraft. At best they will be guessing at the condition their batteries are in and hoping for the best. Neither guessing or hope are things to be relied on.
Just an info thing, that your battery recovered over 1/2v during descent should make you consider internal resistance might increased since you first got the battery. I’ll suggest visiting www.batteryuniversity.com as has been done for others to learn more about the factors that affect battery performance, and how IR reduces battery efficiency.
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If you add .txt to the extension, your telemetry files will upload correctly.
Hi PatR
Thanks for the reply, the battery was charged fully Saturday evening, it started at 16.6v and was sat idling (not the motors) for some 14min. I appreciate the workings of Lipo but failed to buy a decent charger for my Typhoon as I was in two minds as to keeping it or selling it, I can be a bit fickle with "hobbies". Due to a number of RL issues I have been unable to use it much in the last few months and have favoured my spark due to its portability. I bought the H back in Nov 2016 so I was thinking it's a combination of age, lack of charge cycles and shoddy maintenance on my part, despite trying to store them at appx 15.4v and monitoring them on a regular basis.
As for landing at 13.9v, it happened pretty quick I got the warning at 14.7v so I flipped the switch to RTH but the H had to climb from 40m to 74m (can't recall setting that height as RTH but memory lapses with age!) within a few moments the battery metre was empty.
Don't misunderstand my post, I'm not whining about battery performance in this instance simply sharing an experience, a learning one with a happy ending. My 4 batteries are labelled, I will check them all with some low level flight testing to see if any others are a bit on the duff side.
PatR
Premium Pilot
Thanks for the info expansion. Something to note, an H battery in good condition will not deplete from 16.6v to 15.9v in 14 minutes if the motors are not armed. They should drop only 1/10v or so over a span of about 5 minutes. I’ve done some presentations with an H on a table lasting over half an hour with the gimbal panning and pumping video to a monitor for public display. Voltage drop during that time span was only half a volt.
In essence, that 7/10v drop in voltage over the short 14 minute time span was an indicator the battery is no longer healthy. You might consider obtaining some less expensive tools that will permit accurately assessing battery condition to prevent such an alarming event occurring in the future. As our batteries are our “gas tanks” we really need to know what’s in them, and if the gas is good or old and gone sour.
In essence, that 7/10v drop in voltage over the short 14 minute time span was an indicator the battery is no longer healthy. You might consider obtaining some less expensive tools that will permit accurately assessing battery condition to prevent such an alarming event occurring in the future. As our batteries are our “gas tanks” we really need to know what’s in them, and if the gas is good or old and gone sour.
I will post the tele files tomorrow, they are on my work computer. I shall look into some metres to check my batteries..
KEITH, was your flight on a cold morning? I had a similar issue one morning with a 2-year old battery that had been in the cold car all night. It flew for maybe 30-s when I got the low-battery "land" warning. I brought it back, shut down, re-seated the battery and flew again for several minutes with no problem. I assume that the battery warmed up during the brief flight enough to operate normally. This is fall, and the batteries don't like cold temperatures.
it was not that cold out just pretty darn windy temperatures 57 degrees but the wind I think made it work extremely hard
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