Hovering current

To get more flight time for my “Tarot-680-Pro Pixhawk-2-4-7”, I am planning to change its battery from “6S Lithium Polymer” to High Capacity “Lithium Ion”.

I have log of my hex, fly in worst case (high wind) Please find below log.

Can anyone check current required to hover from log? so that we can see whether “Lithium Ion” feasible for my hex.

The tuning looks quite OK at first glance, so that’s a good start. However you dont have current monitoring working, which would be first on the list of things to set up when considering battery performance.
It may be as simple as changing
since everything else seems pretty standard. Be prepared to try and do some voltage and current calibration work.

There’s both advantages and disadvantages to using LiIon packs too, just off the top of my head:

  • magnetic interference - packs must always be positioned exactly the same or compass will need recalibration, even if changing back to LiPo
  • weight
  • hotspots build up in amongst the cells, depends how they are packed and current draw

LiIon seems to be a lot easier to implement with fixed wing aircraft, the weight doesn’t seem to matter as much and it’s easy to extend flight time.
You might be better off just going with a lighter weight/good quality LiPo that’s not so overrated as the cheap ones. We’ve been getting good performance out of the Turnigy Graphene batteries. They are a little lighter that the equivalent standard lipo, and we get at least 10Ah usable or more out of a 10Ahr battery.

You could play around in ecalc with cell weights (ecalc uses individual cell weights ! ) and do a spreadsheet to compare a whole lot of batteries performance and prices. Look for $ per flight minutes and things like that :slight_smile:
It really depends on actual requirements - do you really just NEED more absolute flight time regardless of cost?? Or just a bit more will be fine, but cost is a consideration.


First I thanks a lot for taking time for this detailed reply.
I am using two Orange 6S LiPo 4200mA, one of batter’s 1st cell damaged in fist week, then I converted both battery from 6S to 5S, now after a month again 1st cell of one battery not working,if this continues one day i shall have 1S battery from 6S.

I am frustrated, and want rock solid solution for battery.

Try to get a single battery pack to fit requirements - using 2 packs together is doubling up some of the overheads like connectors and wire. It’s not much but every gram counts.

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yes, but now i lost trust on LiPo, what do you think of building own 6s from Lithium Ion cells

How low did the cell voltages get?
LiPo packs can usually handle large current draws better than a Li-Ion pack of similar capacity.

Make sure you use an alarm/meter on each of your packs. These pay for themselves very quickly.


Every LiPo pack in use should have one of these plugged into the balance lead. Just don’t leave them on the packs when you are done flying or the meter will slowly drain your pack.

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I’ve had some LiPos that couldn’t handle the C rating that was printed on the side (puffed up), older Turnigy. I think Shawn has the right idea with finding a high quality LiPo.

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You are barking up the wrong tree.

The optimum setup for a 680 Pro is 740Kv Motors, 1355 Props, and a 4S 10000mAh battery. Every thing else is a waste of time. BTDT

Here are some general rules of thumb:

  1. Prop size determines battery cell count and motor KV.
  2. Large props on “low” Kv motors are more efficient than small props on “high” Kv motors.
  3. Adding a “larger” battery does not equate to a linear increase if flight time.

Tarot 680 Pro

Take Off Weight (g) 3157

Battery Capacity (mAh) 10000
Number of Cells 4
Battery Weight (g) 815
Battery Energy Density (Wh/kg) 181.5950920245
Number of Motors 6
Hover Thrust per Motor (g) 526.1666666667
Watts Per Motor 65.33
Motor Efficiency (g/W) 8.053982346
Expected Flight Time (min) 22.6542170519
Flight Time with 20% Reserve (min) 18.1233736415

680 Pro Bare Weight (No LiPo) 2342
Tarot 4006-620Kv Motors
13" x 4.3" Woden Props
X-Rotor 40A OPTO ESCs
Pixhawk Flight Controller
915mHz Telemetry
FrSky X8R
Tarot ‘Small’ Retracts
SJ4000 ‘clone’ camera
2 Axis Gimbal w/8bit SBGC
MultiStar 4S 10000mAh 10C
Craft&Theory Telemetry
OLED Display

Tarot 680 Pro

Take Off Weight (g) 3248
Battery Capacity (mAh) 10400 Motor Efficiency (g/W) 8
Number of Cells 4
Battery Weight (g) 895
Battery Energy Density (Wh/kg) 171.9776536313
Number of Motors 6
Watts Per Motor 67
Hover Thrust per Motor (g) 541.3333333333
Motor Efficiency (g/W) 8
Expected Flight Time (min) 22.7467980296
Flight Time with 20% Reserve (min) 18.1974384236

680 Pro Bare Weight (No LiPo) 2353
Turnigy 4006-740Kv
13" x 5.5" CF Props
X-Rotor 40A OPTO ESCs
Pixhawk Flight Controller
915mHz Telemetry
FrSky X8R
Tarot ‘Small’ Retracts
SJ4000 ‘clone’ camera
2 Axis Gimbal w/8bit SBGC
Tattu 4S 10400 15C (2 5200mAh in parallel)
Craft&Theory Telemetry
OLED Display

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Hi Shawn,
Sharing log with parameter BATT_MONITOR=4

Please check when you get time and see if we can use li ion batteries?

Sharing exact configuration of my Hexacopter
1)Frame:Tarot 680 PRO Folding Hexacopter Frame
2)Motors:6x Tarot 4108 High Power Brushless Motor (380kv)
3)Propeller:3x Tarot 1355 Carbon Propellers (Two Holes / CW and CCW)
4)ESC (Electronic Speed Controls):6x Hobbywing XRotor 40A-OPTO ESC
5)Flight Controller:PIXHAWK PX4 2.4.7
6)Radio Transmitter:FrSky Taranis Q X7 Access 2.4GHz 24CH Mode2 Transmitter with R9M 2019 Long Range Module
7)Radio Receiver:FrSky R9 SX ACCESS OTA 6/16CH PWM/SBUS Long Range Enhanced RC Receiver Support S.Port/F.Port for RC Drone - 915MHZ
8)Battery:2xOrange 4200mAh 6S 35C/70C Lithium polymer battery Pack (LiPo)
9)Charger:ToolkitRC M8S 400W 18A Color Screen Balance Charger Discharger for 1-8S Lipo LiHV Life Lion NiMh Pb Battery
10)Charging Board:Parallel charging Board for 6 packs 2~6S (XT-60)
11)Power Supply:LRS-350-24 Mean Well SMPS - 24V 14.6A - 350.4W Metal Power Supply
12)FPV Camera:Foxeer Micro Falkor 2 1200TVL FPV Camera PAL/NTSC 16:9/4:3 GWDR No Freeze
13)Audio/Video Transmitter:TS832 48Ch 5.8G 600mW Wireless Audio/Video Transmitter for FPV RC
14)Audio/Video Receiver:5.8G FPV Receiver for Android Phones or computer OTG
15)Camera Gimbal:2 Axis Brushless Action Camera Gimbal with Controller Support Remote Control for GoPro FPV Racing RC Drone
16)Radio Transmitter Battery:2xSanyo NCR18650GA 3500mAh 10A Battery

That is all well and good.

How much does the aircraft weigh with the battery installed?

Hate to say this but your log files are useless. It is obvious the Battery Monitor is not calibrated. There is no way 6 motors only draw 1.5 amps.

Assuming the aircraft weighs 3 kilograms, and using the data on the motor test chart, on 6S each motor should be drawing at least 2.5 amps for a total current draw of 15Amps.

Also, either those batteries are crap, or you are doing something wrong. Cells don’t fail for no reason…

Just a heads up that Li-Ion batteries probably require more care than Li-Pos. So - if you are having cells fail on Li-Pos don’t expect the issue to go away with a swap to Li-Ion.

Properly dispose of your damaged 6S batteries and buy One (1) new LiPo battery with the capacity you need.

This is comical.

May be Orange brand is not good for lipo then.
But liion will give me long flight find right?

I remember Turnigy Graphene lipos were recommended around here. I think you really want to stick with lipo technology. The quality of lipos varies considerably. I’ve had great and bad batteries from the same mfg. The product line seems to be the most important

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Don’t you just love it when you are ignored?


Some packs have a build-in Battery Management System (BMS) which should help balance all the cells but they are costly. In addition, stating the obvious do not store them at full capacity.

Not to make an AD but consider using ChinaHobbyLine Lipo batteries you can also find some coupons around in forms.

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@MrNams from looking at your replies you should really think about why is your current LiPo battery pack failing? Once you figure that out, are happy with the performance, and learn a bit more about LiPo vs Li-Ion care, dangers, etc then think about Li-Ion.

LI-Ion are for advanced users! There is a lot more work to use them safely.

Why is your current battery failing? And how are you determining a cell has failed?

  • Just a cheap battery?
  • Mechanical failure? Example: one cell is bulging
  • Electrical failure?: Example one cell is much lower in voltage than others after discharge
  • Are you short circuiting just the battery somehow?

Also from your questions taking apart batteries with a failing cell, and flying the “fixed” now 1S smaller battery is not something you should be doing yet.

Why fly something that has already failed you before?? Maybe do what you describe for a rover or power ground station equipment, but even then … fire…

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and to add to what Josh posted, for best performance, tune after doing anything to the battery besides charging (moving it a little, swapping for a slightly bigger battery…). AP is quite robust and could probably handle any changes but you’re moving further from an optimal setup. I leave my lipo pretty much permanently fixed to the multirotor so as to not cause any changes to balance or EMI (the mags are sensitive).

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Thanks a lot all.
@hendjosh Josh, My battery never had mechanical failure,no short circuit at all, looks you first point is valid i.e. Orange LiPo are cheap batteries.

@Derek Derek, I did same, I never take out batteries for charge, i charge them over my hex.

Surprisingly even after battery calibration in mission planner, my log shows current drawn from 0-5Amp only? Is there any more accurate tool to measure current drawn, may be some portable tool to measure only current and connect them in series while take off and let it save max current?