Hello guest, if you read this it means you are not registered. Click here to register in a few simple steps, you will enjoy all features of our Forum.
This forum uses cookies
This forum makes use of cookies to store your login information if you are registered, and your last visit if you are not. Cookies are small text documents stored on your computer; the cookies set by this forum can only be used on this website and pose no security risk. Cookies on this forum also track the specific topics you have read and when you last read them. Please confirm whether you accept or reject these cookies being set.

A cookie will be stored in your browser regardless of choice to prevent you being asked this question again. You will be able to change your cookie settings at any time using the link in the footer.

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Lipo Battery Question
#1
How do you guys figure out when to stop flying your quad because the battery is getting to low? If my goggles have a 7.4V 2200mAh at what voltage should I recharge the battery? 
Also if I am flying with a 1300 mAh 4s 15.2 V battery when would you guys decide it is time to bring it home?
Reply
Login to remove this ad | Register Here
#2
You should never discharge a lipo lower than 3 volts per cell, but to keep my batteries happy I never go lower than 3.2 volts. There are different ways to monitor your battery level, a lot of flight controllers now have Betaflight OSD so that you can monitor your levels, or you can use a simple low voltage alarm that plugs into the balance plug of your battery

https://www.ebay.ca/itm/RC-Lipo-Battery-...Swg8taOkBR
[-] The following 1 user Likes RENOV8R's post:
  • kaitylynn
Reply
#3
For KT-210 using 1300mah 4s packs, I set a flight timer on my radio for 4 minutes. At that point I start watching my average cell voltage and I land when the the FC guesses them to be about 3.4v. I have not over discharged my 4s packs, but I have a 3s pack on KT-125 that I landed because there was not enough power to keep the craft aloft. That ruined the pack, so I now figure better safe than sorry!
SoCal Kaity :D
OMG, no one told me it would be this much fun!  Addicted :)
Reply
#4
You have many choices to monitor your battery.
For me at begining was the buzzer with low voltage alarm.

And about batteries if im remeber this correct

at 100% you have 4,2V
if you get to 3,8 you consumed 65% of battery
3,7 is 87% of capacity consumed
3,6 is 97% of capacity consumed

So for me 3,6 is best to stop because you used maximum power without damaging the battery.
Reply
#5
I have warning go off around 3.4v. And try to land around 3. 2-3.3V. I found that my high C-rate quickly drops voltage below that. I don't fly on time because sometimes I very aggressively and other times I just cruise.
Reply
#6
My craft hovers at about 50% throttle. When it starts to need 60% and it's over 5 mins on the timer, I tend to bring it in.
Reply
#7
With a 2s I'd land at about 6.5 - 6.6v, remember though, that voltage sags quickly at high throttle and then rises again. If you can properly calibrate mAh draw that is the most accurate way gauge how much of the battery's capacity you have used.
Windless fields and smokeless builds
[-] The following 1 user Likes Tom BD Bad's post:
  • unseen
Reply
#8
> How do you guys figure out when to stop flying your quad because the battery is getting to low?

1. My onboard buzzer starts beeping. (via FC VBAT - Configured via Betaflight)
2. My Taranis warns me using a voice prompt. (using X4RSB telemetry)
3. The voltage value in my OSD starts flashing.

All 3 are set up to warn me at 3.6v per cell or 14.4v (4S) total. That way, I figured, I've got every scenario covered. Should the quad be to far away to hear and I happen to miss the OSD warning my Taranis will shout out a warning.

I havn't gotten around to calibrating my mAh draw yet, but that would probably be the safer bet.
If my post helped you...hit the RATE button.
Reply
#9
A properly calibrated current sensor is the best way to answer the 'when should I land?' question.

Once you have used 80% of your battery's capacity, it's time to land. This should leave your battery at a resting voltage of about 3.7V after it has recovered for a few minutes.

It's also a good way to see if a battery is starting to get old. As batteries age, their capacity starts to reduce, so if a battery that could previously deliver 80% of its capacity and recover to 3.7V only recovers to 3.5V, it's time to think about retiring it.
[-] The following 3 users Like unseen's post:
  • kaitylynn, Esy, Tom BD Bad
Reply
#10
you might find this useful:
https://oscarliang.com/monitor-measure-b...arm-drone/
Don't be a LOS'er, be an FPV'er :)  My Gear - Facebook - Instagram - Twitter
Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Best Battery Option for Build - Begginer Arkadius27 7 150 19-Mar-2024, 04:40 PM
Last Post: Pathfinder075
  Smoke, Fire, and Sparks when I plug in battery NickyWicker 7 1,571 06-Mar-2024, 09:39 AM
Last Post: home003
  Soldering question Hummus 8 248 05-Mar-2024, 02:09 AM
Last Post: Pathfinder075
Wink Stupid question: Eyes.fpv 4 164 03-Mar-2024, 05:44 PM
Last Post: husafreak
Exclamation Noob Question..... "VTX/ESC" Boards.... Coleon 12 267 02-Mar-2024, 12:35 PM
Last Post: Luk5569


Login to remove this ad | Register Here