The safest way to calibrate your Betaflight current sensor

Your current sensor is inaccurate. Your mAh is completely wrong. You need to calibrate your current sensor! You can do it with a clamp meter, spinning your motors on the bench, and risk death and dismemberment from your props. Or you can do it this way, which involves zero personal risk. And just a little bit math.

[@NJ-Tech]

a big high-four to those that learned the hard way!

[@slothFPV]

i get it lol

[@mr.feeshfpv7799]

Same literally just almost chopped my finger tip off

[@DanRichmondFPV]

Lol

[@bento1132]

A big high

[@SunriseWaterMedia]

Ouch 😂

[@supergary]

For quick reference: New scale = Old scale * (Betaflight mAh consumed / Charger current charged)

[@bartsoj]

From what JB says it's more like New scale = Old scale + Old scale * (1 - Charger current charged / Betaflight mAh consumed) If we take the numbers in your formula it is 220 * (5000 / 4485) = 245, which is wrong In my formula it is 220 + 220 * (1 - 4485 / 5000) = 242, which is corrent But maybe JB is wrong and 245 is the correct number

[@MrStevegibb]

@@bartsoj actually thinking about it your adjusting the betalight measurement and therefore you need to know the percentage of the betaflight measurement it needs to be increased not the percentage of the charger measurement. So the the formula above is in fact correct as you are given a correction factor relative to the betaflight measurement and how far it was wrong.

[@Kabab]

I was so confused about this and too lazy to do the research. Thank you. now I'll actually do it.

[@user-cx5no9oi2w]

If you have a charger with power output option like toolkit rc it’s so much easier. Just plug it in and check if they match up. But I didn’t know what settings to change in beta flight. Thanks JB for showing where to find the voltage / amp scale.

[@-sickfast434]

i fell asleep for three vids and still learned something today osmosis lol my wife says your voice puts her to sleep what a soothing tone

[@Deathwish_fpv]

thank you sir. i really like your videos.. lots if info that you have...im still learning all about this hobby.i have been in this about 6 months

[@adamk.3946]

joshua, a different way to calibrate the current sensor that I know of on the betaflight F3 is to measure the resistance of a little resistor towards the outside of the board right by the shunt resistor. I find this method to work spot on every time! for most betaflight F3 it's between 43k-45k. take that value divided by 200 and that is just about perfectly what you need for your calibration value , 220 (ish). I think most other flight controllers use the same method and it's super accurate, just finding the resistor can be a pain on other boards.

[@JoshuaBardwell]

This doesn't take into account the variance in the value of the shunt resistor though.

[@JoshuaBardwell]

It will get you within a few percent, to be fair.

[@adamk.3946]

Joshua Bardwell yeah very true, I usually end up tweaking the value just a tiny bit. I never thought about the shunt and how they all vary, just tweaked the value and went with it. learning something every day! thanks man, great videos as always!

[@jussa101]

This is actually really smart it won't be dead on but nice part is you can always use this as a good baseline.

[@fatal510]

do you got a link to any video resources on this or a rcgroup thread with pictures?

[@helihubby]

Again, I did learn something today. Thanks Joshua.

[@ASJC27]

What timing! I just finished calibrating that way like 5 minutes before you uploaded.

[@1320fastback]

Thank you Sir, I did learn something and got my FC calibrated.

[@richardaffonso]

Another informative video. thanks Josh.

[@tylerwilliams786]

You shld do video on betaflight 4.1 current sensor,and how to set. Theres a calibrate button now down by the save button. I'm still trying to figure it out. Thnk you for all u do. Great help in our hobby👍

[@GregQuillen]

yeah noticed that but havent tried it.. i used isdt batterygo to read voltage and set it

[@deathpvfpv1483]

Im kinda new to all this (2 months) and did it by flying a batt for 100mAh using my momentary switch as a mAh readout, just hovered and disarmed at 100mAh and went n chucked it on charge, tweaked the sensor scale then out again and back in ect till it was equal, now it still stays within 10-20mAh even at 1000mAh used, much better than trying to guess a voltage readout under battery sag, get so much more from my batts now!

[@csabafarkas6738]

Do you charge the batteries fast charge, charge or balance charge?

[@duanneoloughlin9449]

Thank you Mr bardwell. My osd was reading i was using 3000mah+ from a 1300mah battery on my zues f7. All fixed now

[@TheHeliman9]

I recently have had my current sensor stop working after working fine for many months.its the matek f405 It mysteriously stopped working and no sign of damage.is there a way to test and or check this.ive Google searched to no avail.thanks

[@InfinityDrones]

Nice video, very helpful. However I have a question on battery voltage not showing correctly... When I plug my fully charged 4S battery into my quad the voltage used to show 15.6. I've gone into betaflight and in the power & battery tab change the scale up all the way to 152 and now it ready the battery correctly at 16.8v (while the battery checker is plugged in). But I've taken one of my other batteries that are in storage mode 14.8v... and checked again... Voltage still shows at 16.8 even though the plugged-in battery checker displays 14.8... Any ideas as to what I'm doing wrong here?

[@rafayczkowski2757]

I am wondering trying to understand the relation between capacity eaten and cell's voltage. For the 2300 mah battery, does this mean that single flight run should be able to eat this 2300 mah (due to betaflights stats) and then around that I will have ~3.2V cell? Or if I would eat 2300 mah cell voltage will drop to 0V? (question). Currently I am flying at 3S 2300 mah, and after eating 1000 mah my cells are at 3.6V

[@vinnnocc]

hello i’m running 32bit esc using the telemetry for my current. is their a scale i need to adjust? i’m getting 70amps from a burst. with 2300kv fire motors on dal5046c props. chnl 1300mah 4s

[@jaybird6909]

So I'm trying to calibrate mine on my spedix gs35a 4 in 1 and while sitting unarmed it shows that I'm pulling 2.5 to 3 amps. In order to even get the amps down to 1 amp or lower I have to adjust the scale to 1150. I know that's not normal. I've been told not to worry about it and calibrate to what actually happens in flight. But with it pulling at 2.5 amps at all times the mah consumed is going to be off. What would you suggest? I've tried offset -100 and scale 700 and it was at .9 amps but that doesn't seem right at all

[@cooperlile2990]

Hey Joshua, I've built 2 copters now with the betaflight f4, a chameleon and now a rooster. I watched this video and successfully calibrated my current sensor on my first board, my scale value turned out to be pretty accurate around 250, but I can't get it to read anything on my second. I did everything exactly the same in the configurator and can't get the current sensor on my rooster to read anything. I enabled it and selected on-board adc, I'm running betaflight 3.2.2 on the newest version of the configurator 10.1.0. It reads 0 amps and 0 mah after about 3 minutes of flying... any ideas?

[@marcepanb]

I just want to share my way of calibrating current sensor. As you can see there is scale an offset. This mean betaflight is using linear equation to calculate true current flow (current = measurement / scale - offset -> y=ax+b). Built-in current sensor is accurate only for current above ~1Amp. In betaflight you set scale to 10 and offset to 0. Next you measure (without the props and with external current meter) two points, at maximum throttle and 1/3. Every time write down current from current meter (CM) and sensor (CS) (but reading from sensor must be multiplied by 10). Now you must solve system of linear equation {CM_1=CS_1*a+b,CM_2=CS_2*a+b}. If you solve, offset is -b and scale i 1/a.

[@JoshuaBardwell]

+marcepanb why do you start with the assumption that 10 is the correct scale.

[@marcepanb]

Correct value should be 1, but then value is clipped to maximum (for me it's 327.67A). So I set scale to 10 to divide value, but for calculation I multiply this value.

[@Bobby_Strange]

In the OSD, is the current sensor giving overall Amps? So my noob troubleshooting a F440 (40x4=160?), that bumps 39A max (per calibrated HGLRC XT60 sensor with R-Line 1300 75c), is being limited for the brother hobby 1507s I have on there (20Ax4=80 @100% on Lum 3040)? It appears the F440 is 10x4 and is misleading to be called 40A.

[@user-nb7fr9kb8j]

Thanks for the vid. I selected battery in OSD on bf but get a zero, so I don’t get single battery volts just total which is always under which I will now adjust after watching this thanks 👏

[@brandonb86]

Thanks for this video!! I will be doing this calibration shortly, I just completed two build usng the HGLRC v5 pro that you did a video on and is my frist OSD build. Can you help me with the battery voltage settings ? I know batteries sag while flying but I have no idea what to set the limits to. I just always flew with a timer but now that I have the bells and whistles it'd be nice to be safer on my Lipos. Thanks again for all your work!!

[@V8Power5300]

I watched your first unsafe video and did the calibration. I saw the safe video and was like naa. I'm gonna do it in an unsafe way. It worked perfectly fine for me

[@stickboyfpv4742]

Hahahah right🤣

[@furulevi]

My flight controller has barometer, in Betaflight Configurator "Baro" is yellow on the top of the page, but Baro is not showing up on the Modes page. Is there a command to enable it? Thanks!

[@JoshuaBardwell]

I don't think the mode is called Baro. I think it's Altitude Hold. But to be honest I never use that feature so I can't be sure.

[@paulvallejo]

Dude it's almost like you're psychic or something. Thanks for another great video

[@ceecrb1]

I have often thought of just using a dummy load and current meter, before installing the board in quad. Never gotten round to trying it.

[@gazeddy]

ceecrb1 I used a 1amp electronic load hooked up where the esc connects (I use matek pdb's with current sensor) to work it out

[@fpvwing]

Easier calc: new scaling factor= Osd ÷ actual x old scaling factor (edited)

[@LosAngeles234]

How do i calibrate my Mobula7 current sensor? I can't monitor the charged mahs with my charger... I updated Betaflight to 4.2 and now it says I drained 650mah from a 250mah battery :(

[@brandonwoodford579]

i took out 900 on my osd, and put 1300 back in. this is slightly opposite to what you have. i need to go the other direction. mine is reading low.

[@BobCorey]

Nice videos, thank you!

[@Thermal694]

My current I reading backwards. Example: When I throttle up the current goes down with amps. Then I drop the throttle current goes up. I have the kakute f7. Does anyone know how to fix this?

[@alexdij4025]

What about the heat generated in the battery. Heat requires energy. The current sensor doesn't record the energy used when the battery heats up right? That might account for the apx. 100mah per battery.

[@GregQuillen]

This will change blackbox Amp reading too? because my OSD mah reading is always half of what charger puts in... I have 2 different chargers.. 525mah battery going down to 13v still on OSD saying only used 276mah lol

[@DudaZachary]

The voltage regulator on mine seem a bit wonky. battery plugged in on the bench says it burns through 100mah in the matter of seconds. That cant be right. can someone give me a basline number to change it to? I'm using Lumenier 4s 1300's. Thanks

[@blitzvinnigFPV]

Please, can somebody answer this

[@EpicSheepReloaded]

finally :D if you would have told me earlier, my friends would still have all their fingers...

[@JoshuaBardwell]

At least your current sensors are calibrated.

[@EpicSheepReloaded]

not really.. their screams where so annoying, i had to stop before i got it calibrated...

[@gazeddy]

SwissGravityForce that's what ear defenders are for

[@BrassStacks]

SwissGravityForce , Quitter

[@BuzZ.]

SwissGravityForce hello. is in betaflight button to calibrate controller? because I bought fs i6 and one stick is not to middle is just slightly turned to the right :(

[@joel3384]

i have a sp racing f3 fw 3.3.2 betaflight on a mana 285 it flys good pid stock with some tweaking

[@roccofpv2191]

Thanks for the video, I have the Holybro Kakute F7 and a Tekko32 4in1 esc (35A) running Betaflight v4.0.4 I have it configured to work off the ESC Sensor. Ports Tab set to use UART7 for the ESC. In the Configuration Tab, enable “ESC_Sensor“ feature. In the “Power & Battery” tab I selected “ESC Sensor”. I have DShot 1200 as the ESC protocol. How do you adjusted for the mAh usage on the battery? I understand the current sensor calibration procedure on a FC, but is there a way to do it for this type of ESC configuration? the current adjustment is not available in Betaflight v4.0.4 on the power tab. Any help would be great. thanks

[@ThePurpleSnork]

RoccoFPV I have that same ESC along with the Lumenier LUX F7 and dshot600 is my best option. I wonder why...

[@Diggsiii]

Hey Joshua, how do I get Battery to show up in Betaflight? Everything seems fine and well, but i get a blinking 0.00 voltage in my OSD and BF doesn't even pick it up.

[@SPAZit101]

I have one quad thats like waaaay off. It just keeps climbing in the osd up to like 7000 or whatever but its really only drawing something like 700. Process different for something that off or different for 4.1?

[@timreichertyoutube]

I have the same issue, mine starts climbing when I plug in the battery. BF 4.1.4 iFlight Bumblebee

[@mattsupertramp6506]

Yep same...hopefully this works

[@PoJargon]

Joshua, cheers you you! I have learned so much from your videos... you brought me from tinkering and failing to full success. I have a problem with tuning my battery and seeing low voltage warning messages in my osd. I have a 20x20 hglrc f4 stack and just cant seem to get it right. voltage seems correct when testing with a voltmeter, but the battery never hits the voltages to send the message to the osd. Any help would be greatly appreciated. Also, what is your paypal for donations??

[@dominikkammer2478]

Could you: -also check the voltage after flying -Charge it up -discharge to the voltage you got after flying (Difference of charging to discharging mah is around 220mah. Pretty big difference) I think when you discharge it won't have to balance the cells that much -> more accurate?

[@Martin1519]

Will one current sensor setting work accurately when using 4, 5, and 6S batteries, or do I have to recalibrate every time I use a different volt battery?

[@JoshuaBardwell]

The current sensor should be accurate regardless of voltage.

[@sheabutter173]

for me the mah on the osd sensor ...shows the mah rapidly climbing faster than the seconds ...on my Babyhawk 3in with a 550mah it will run up to 500mah used in 2min the voltage is at 12.5 ...plug it in to the D6 charger only 125mah put back in....so obviously something is wrong . i have calibrated current sensor...

[@31carny]

what if you replaced the esc's with a dummy load eg incadecent light buld of a know output and measure overtime?

[@ChaddRainsFPV]

31carny - this is a good idea buddy

[@JoshuaBardwell]

If you are measuring mAh then I don't know why you don't just spin the motors instead.

[@ChaddRainsFPV]

Joshua Bardwell - I think he is saying to use a known load for a specific amount of time and measure the mAh from the osd. What the load should have exerted vs what the osd said would give your percentage the same as spinning props. It's not as fun as flying, but should just the same no?

[@DangerDavefpv]

whats your beta f3 current scale set too?

[@Away907]

Thanks! BTW, lipo battery cycle effectiveness is close to, but not 100%. Some energy dissipated as a heat, some turns into chemistry which kills the battery over time. Different sources are giving numbers 90-98%. To get "true" amp reading during the flight one should add additional coefficient to compensate that. But i primary interested in correct mah reading to know the remaining battery capacity without any kind of math. So my current sensors are calibrated exactly the same way as you mentioned.

[@JoshuaBardwell]

The main source of inaccuracy would be the balance program.

[@romangorchakov]

Hey Josh! In this case the sensor reads higher, but what if it reads lower, do I still divide "mAhs put back in" by "mAhs consumed", or do I divide a smaller mAhs by higher mAhs? Thank you!

[@JoshuaBardwell]

The math is the same. It will produce a multiplier either greater or less than 1 depending on whether the sensor reads higher or lower.

[@archer4922]

Just found this vid. My betafpv 65s on the osd says I used 2134mah on a 230mah battery. It's waaaayyyyyy off.

[@flyinghighoveryou4872]

My mobula 7 is beeping with 2s single battery. Beta flight will only let me put 5 for maximum cell voltage. What am I missing? Thanks for any help.

[@JoshuaBardwell]

The cell voltage is .... the cell voltage. Not the pack voltage. So you just set it to 4.4 or 4.5 if you're charging to HV and that should be fine. If it's beeping with a single battery then maybe it's not auto-detecting the number of cells correctly. Put the Average Cell Voltage in the OSD and see if it thinks the average is equal to the pack voltage or 1/2 of it. This would indicate it mistakenly thought the 1S was a discharged 2S.

[@InFrontOfYourBack1]

Great idea! Much safer and close enough. Question..if you use different size (mah) batteries, once calibrated, will the current sensor be correct across different batteries. What about between 3S to 4S?

[@JoshuaBardwell]

Yes and yes.

[@eddie_Za]

How do i know how much the battery charger put in the battery if im using a eachine 1s charger. It lights when charging n blink when full..

[@JoshuaBardwell]

You would need a charger that reports mAh.

[@CountryMaster16]

so you showed how to do it withj am fc how about calibrating a frsky voltage sensor through the reciever?

[@JoshuaBardwell]

Just adjust voltage scale until it matches a multimeter reading. But the voltage scale is usually pretty close to accurate.

[@PhasedragonWF]

Is there a reason you can't just spin your motors without the props? Obviously it won't draw as much, but it should be enough to get a baseline. 2 data points define a line, you don't need a 3rd way up at 80 amps

[@JoshuaBardwell]

The closer together the two measurement points are, the more precise they have to be to correctly define the line. The further apart the two points are, the less precise they have to be to correctly define the line. The amps drawn are not constant. They're going up and down and you have to guess what the correct average is. If you tried to take a measurement at, say, 3 amps and 5 amps, you would be way off.

[@AndyRial]

My current sensor is way off on my JB F4. I’m showing 1455mah used out of 1300mah pack. Putting back in 950mah. I’ve upped the censor calibration to 280 from stock 250 and I’m still getting the incorrect info. Gonna teat at 300 and see but doesn’t seem right.

[@JoshuaBardwell]

+Hurricane FPV you have to calibrate then from default. The default value is never right. It's normal.

[@AndyRial]

Joshua Bardwell default being 250 have you seen the need to go above 300 in some copters? I edited my original post after realizing I posted my second to last settings in error.

[@beelzelboss]

So what if we have a wiring harness and a fc with a current sensor. For example I run a dis f4 aio with a an extra wire running from the battery positive to all of the positive esc. I fear that the bigger motors will draw too much amperage and fry the aio unit on 6S. Will this methodology still work?

[@JoshuaBardwell]

+beelzelboss if you have run a wire from battery positive to the ESC, I don't think the current sensor should work at all because current isn't passing through the shunt resistor.

[@beelzelboss]

Okay that's what I thought since the electricity will take the path of least resistance which in my mind is not through the resistor but through the wiring harness, since it is on both the positive and negative. Thanks for your reply. You've unlocked a bevy of knowledge for me these past couple of years. If only you could get into the Crossfire game and some 6S!

[@miahndes]

Hey Joshua, This is a bit off topic, but I was wondering if you know how I can calibrate the barometer that comes with my F3 omnibus. I like it but sometimes when I fly the reading says -8 ft when I'm starting at.... Not that I'm needing it to be super accurate, it would just be neat to know it's pretty accurate.

[@JoshuaBardwell]

I don't think baro is ever really accurate on these copters unless it is supplemented with GPS. Have you installed foam over the baro to protect it from changing air pressure due to propwash?

[@andrewdowney760]

Need some help Josh and friends so flew 13 lipos. Got an average of 892mah when bff3 showed 1000. Also is it normal to have such a difference? Got 821 to 945 most were 900ish give or take 20. Anyway what increase should I be putting in?

[@JoshuaBardwell]

I put the exact math in the video. What part of it didn't you understand?

[@andrewdowney760]

Joshua Bardwell Nice comment and great help so if my math is right its 12.5% high for me. So I multiply this by what the setting is at to get a better calibration?

[@TheDarmach]

And how about using something else to put a load on PDB? Like connecting 12V halogen bulb to the PDB output? Wouldn't it be enough to load PDB for calibration?

[@csabafarkas6738]

Yes, sounds better :D

[@rafur9982]

This is a methodology I used since many quads and work fine. This is what we can call an iterative process, and usually after 4 or 5 try, I get the correct number ! Just one comment, because this method didn't take into account the offset of current, which is another BF parameter. By default, the offset is set to 0 in BF, that mean that when the lipo is plugged in, the current seen by BF is 0, but of course it is not, because of flight controller, led, esc and others stuff you put on your quad, always need current even with throttle at 0. So what I usually do for that is that the offset current for a basic configuration is somewhere between 300 and 400mah, so I set the parameter in BF to 35, so as soon as I plug the battery, I see in the osd a current of 350mah. And it work perfectly fine for me :) Happy flying

[@JoshuaBardwell]

I don't think that's how offset works, but I could be wrong. I think that offset is for the case where the current sensor does not output 0 volts at 0 amps.

[@rafur9982]

I just realized that I do that because I use a virtual sensor and not a real current sensor :) I personnaly prefer having the mAh used in addition of Lipo voltage on all my quad, because it's often difficult to see the landing point, as voltage changing a lot during a hard fly... So in case of using a real current sensor, you're absolutely right, no special need to change this parameter in BF ;)

[@BertMaas]

Oh man I have been messing with my current sensor all weekend. If only I looked earlier :')

[@bobbfwed]

In one of your more recent videos, you state that an amperage meter scale of about 250 is correct for your flight controller. My amp readings, and mAh were clearly very high on my latest build using your flight controller, so I did the method stated in this video and the value came out to 374 (using the average of 6 batteries). From my few flights since the calibration, it is clearly way more accurate, but why is there such a wild variation from the 250 you said it should be near? If it changes anything, I did pre-order your board (so I might have an early version), and I am running Betaflight 3.3.1.

[@JoshuaBardwell]

It seems like there may be more variance in the resistor values than you would expect. I'm surprised that value is so high.

[@FPVPreacher]

is there any way to do this from an esc onboard sensor? For example i'm using the Kakute f7 stack that comes with the tekko_32 35amp 4-in-1 esc? I know that esc sensors only show the motor current drawn however i'm seeing a deviation of almost 35% which seems very high. I know its not perfect but 35% over the motors seems like much more than my VTX and FC could possibly be pulling. Any ideas?

[@JoshuaBardwell]

You can calibrate blheli32 current sensors in blhelisuite32

[@FPVPreacher]

@@JoshuaBardwell Thanks ill research how to do that.

[@Paube78]

Hey Joshua thanks for this video but alas my mah count rise very quickly can't seem to slow it down . I'm running 600mah on my whoop and I fly for about 4 mins when I land my battery checker says 3.4 volts but my beatflight said 1300mah. What am I doing wrong "BF settings is wrong on my end ?? Plz 🙏help thx brotha 🤜🤛

[@blitzvinnigFPV]

Please can somebody answer this question

[@terpsquirter7107]

Why will my voltage and per cell voltage appear but my mah just stays at 000 in my goggles?

[@andrewfrater6238]

Can you do this on the new beatflight 4.2.0 there is no section that is labeled current sensor under configuration anymore? I just have the new section labeled battery and there is voltage meter and amperage meter?

[@JoshuaBardwell]

It's in the Power and Battery tab now.

[@andrewfrater6238]

@@JoshuaBardwell Thanks!

[@HB-jf6yq]

Hello, im having problems. I recently bought the spektrum dx6 and the ar610 and ive bound them but i cant see any response on betaflight when i move the sticks. Can anyone tell me what settings i need? Or how i can finally get my quad up in the air?

[@JoshuaBardwell]

kzbin.info/www/bejne/kKG4Z2CAjpuZpM0

[@Olitoni]

HB Designs Hehe

[@HB-jf6yq]

Joshua Bardwell I watched the video fully and it still doesnt work. Any ideas?

[@walterheck7034]

i am using the JBf4 which was reading right on, I just switched to crossfire and now the scale is off. shouldn't the mah draw stay the same? its the same in both quads that I switched to crossfire.

[@JoshuaBardwell]

Yeah the mAh sensor is reported by the FC so switching from SmartPort to Crossfire won't change that. But remember that the Crossfire sensors are totally different than the SmartPort sensors, so you need to either create a new model in your radio, or you need to go to the telemetry screen and "delete all sensors" then "discover sensors". You also may need to change some things, like the battery voltage is reported as rxBat in Crossfire but VFAS in SmartPort, so you need to change the main screen voltage source. This is all covered in my crossfire setup video for what it's worth.

[@walterheck7034]

Joshua Bardwell I went through all the settings. I ran 5 packs and by the math the mah draw is showing 80% of what was actually used. I know you did a video on adjusting for this but I can't seem to find it.

[@SquirrelSings1]

Mr. B I have a problem with fc. I have a built and been flying quad and a new f3 Fb and neither one will connect too beta flight . I get one getting bricked but a brand new one too.? Everything I do nothing will let it connect to make changes

[@clutester]

Not Mr. B but sounds like your computer needs the drivers to recognize the FC. Check the introduction page of Betaflight.

[@SquirrelSings1]

I've been trying to load all them up on my prehistoric pc. But trying everything I can it's throwing me off but thanks a lot

[@clutester]

I had this issue with an older PC, Windows 7 without any updates. On my win10 laptop it worked without issue. Since then I updated to win 10 on the older PC.

[@DUDLEY588]

I have set my scale to 260 and 275 and my amps sit at 0.30 and just go up a hair under load I tried a lot of different numbers in there and I can't figure it out it's a betaflight f4 board my milliamps consumed also count up get slow showing like 14 mah consumed on a 3 minute flight

[@JoshuaBardwell]

+John lepeshko it sounds like your current sensor is not working. Maybe you wired the board wrong. Are you using a 4 in 1 ESC maybe?

[@andylee596]

I 'm wondering if the current coming out equals to the current coming in to the battery? Is there any efficiency issue in these process? See, in 100 out 88 etc...?

[@JoshuaBardwell]

Current through a system is always constant. If energy is lost to efficiency losses, it is lost as voltage.

[@Bidon555]

I wonder what the COP of the LiPo battery is. It is clear that if you convert 1000 mAh electrical energy (charger reading) into chemical energy, then when you convert back you will get LESS mAh. To be precise, if properly calibrated with this method, the OSD tells us not how much energy we have consumed but how much energy we should put back in to recharge. So if the energy meter is perfectly exact it is normal to show less mAh than what we put in while charging. But anyway, that is not so important since we really care for a way to tell how much of the battery we have consumed - the absolute values are not crucial if we simply know that reading of X mAh means it is time to land.

[@joewakeman1250]

What about clamp meter and props off? Will it not draw enough current to get an accurate calibration?

[@JoshuaBardwell]

I don't think so. If you calibrate at 3-5 amps that won't give you accuracy at higher amps.

[@manuelsmeets9392]

Joshua Bardwell I Calibrated my Current sensor the hard way last week. Like you said in your video i turned around the props and switched them so they push the quad down. I got it pretty spot on. My question now is: I know the value i have to put in to betaflight but do i need to callibrate the current sensor everytime i update the firmware? You make great content. Keep doing what you are doing because I Wasnt even Flying now if it wasnt for you!

[@JoshuaBardwell]

You can simply copy the value when you update the firmware.

[@manuelsmeets9392]

Joshua Bardwell Thank you!

[@pabz06]

I fly 1300mah out of my 1550mah and land at 14.9-15.0V. Accurate?

[@JoshuaBardwell]

Sounds good to me.

[@daneyan1985]

Can i use a multimeter to check pack voltage against the voltage shown in betaflight? That's what I've been doing.

[@JoshuaBardwell]

Voltage and current are different.

[@daneyan1985]

Joshua Bardwell Ahh ok.

[@Seaweedaids]

How does the offset setting work and is it safe to assume it's never needed for most boards?

[@JoshuaBardwell]

The assumption is that the current sensor outputs 0 volts at 0 amps, and then scales between 0 and either 3.3v or 5v depending on the type of sensor. There is a gain resistor that sets the maximum end of the scale and the maximum amps the sensor can detect. So by changing the value of the gain resistor, the board designer can choose to have higher max amps with less resolution, or vice versa. The scale is used to calibrate for the gain resistor. It tells how many amps each volt (or fraction of a volt) the current sensor outputs equates to. The offset would be used if you had a scenario where 0 amps did not equal 0 volts for some reason. But I don't know what that reason might be.

[@cheddergetter]

how do you fix a drifting quad, is it the balance of the quad or is it something else

[@JoshuaBardwell]

First, make sure your channels are centered at 1500 in the receiver tab. Be sure your receiver is powered up and your transmitter is bound or all channels will just lock at 1500.

[@ueber30uwe]

Hi Joshua. A total beginner question. My osd in the Goggle show me the aktual voltage and amps. After the flight i see the used mah. But in the betaflight configurator is no tab for the current Sensor showing so i cant calibrate the used mah like in your video. Configurator is 10.4.1 Fw on fc is 3.5.2 Fc: Rharlance F4 Pro+V2 Or have the FC no current sensor and also the configurator cant show this? Hope for help...Uwe

[@JoshuaBardwell]

If you don't see the Power And Battery tab, click on the gear icon in the upper-right corner of the configurator. Enable "expert mode".

[@ueber30uwe]

Must the quad powerd on with the battery😕 I dont see the current sensor calibrate tab😕

[@JoshuaBardwell]

The quad does not need to be plugged in. You need to enable "Expert Mode". Click the gear icon in the upper-right corner of the configurator window and enable the "Permanently Enable Expert Mode" option.

[@ericeman1093]

its like you opening a dimensional portal in your room

[@SemteVruchte]

Does a current sensor need big wires? because i tried to calibrate it multiple times now and I just saw that it keeps at continuous 8.88A, in idle, hover or full punchout, I dont get it. Can somebody please help?

[@JoshuaBardwell]

You've probably got the wrong sensor selected in the Power and Battery tab.

[@SemteVruchte]

I wish I did, both onboard ADC and i'm filling in the scale at current tab and not voltage tab, I don't get it, also if I increase or decrease the scale the continuous current (8.88A) changes depending on the scale.

[@JoshuaBardwell]

The fact that the current value doesn't change when you throttle up or down is a sure indicator that the sensor is not working. The most likely cause is incorrect sensor selected. Such as on CLRACINGF4 where you need to solder bridge to select internal or external sensor. What's your FC?

[@SemteVruchte]

Its a omnibus f4sd, www.banggood.com/BF3_1_5-Omnibus-F4-V2-Flight-Controller-STM32-F405-MCU-Integrated-OSD-Built-in-5V-BEC-Current-Meter-p-1143258.html?cur_warehouse=CN

[@MrMkeup66]

im having this problem with the Kakute/tekko32 combo. my amps on idle is at like 30 and doesnt change. my mah will be like 1000 in a matter of a minute just with my quad armed and sitting ( no throttle)

[@Klawful2011]

This is smarter, but not as much fun. I did it the hard way with a mate holding it (strapped to his hand, wearing a soccer shin guard as arm protection). And it was amazingly accurate.

[@machinedred]

hi josh , why does my mah sprint up as soon as i connect the battery ,even with the motors stationary and why does my ammeter show 26 amps too? if i raise the throttle and spin the motors the amps goes down not up ! whats going on ?

[@JoshuaBardwell]

+machined red if your ammeter shows 36 amps with the motors not running then probably you have a short circuit somewhere.

[@machinedred]

thx josh , ok its got me thinking , my real inline ammeter between batt and pdb says 0.6a and it flies perfect . what do test or check next ?fc has 1 ground wire and 1 vbatt wire , what have i done wrong ?

[@Junker83]

Hi, I have the same problem. Any solution for this issues?

[@19ncook89]

I'm running Betaflight 3.4 on a Bfight 210. I was going to try this but I can only find the "amperage meter"... no current sensor. I am confused... Can I still adjust my current sensor this way?

[@JoshuaBardwell]

"Amperage meter" in the power and battery tab is the current sensor scaling.

[@19ncook89]

Thanks

[@vektr6278]

JB, once current sensor is calibrated, when we change from 4s to 6s battery, is it necessary to re calibrate?

[@JoshuaBardwell]

no

[@LacedLlamanade]

why do you need to end at a specific MAH? can't you just record the value from OSD when you landed and add them to average it without the clean numbers?

[@JoshuaBardwell]

Sure you can do that. It's just easier if you stop several packs at the same mAh so you don't have to write down and remember which pack stopped at which value.

[@Ballistik1]

Let me first thank you for what you do for the community and myself, your videos are very informative and extremely helpful to many of us. Anyways with this method and or any other method to calibrate the current sensor, will the values of one board be the same as the same board on another quad? For example we have run multiple packs through one of my sons race quads and on 5 packs each time we end up putting 99% back into the batteries as what was taken out, so we also have 5 other quads with the same board (dys f4). So can we use the same values from the one quad on all the other quads or is each board regardless being the same board going to be different? Again thanks for all that you do for us!

[@JoshuaBardwell]

No, they won't be exactly the same, but they will be close. The resistor that is used to set the gain of the current sensor has some manufacturing variance. If a good quality resistor is used, the variance should be less than 1%. But it's up to the manufacturer to use a good quality resistor :-)

[@Ballistik1]

so what kind of variance could I expect from one board to the next?

[@gwizzfpv6741]

hi could you help I am trying to do my amp I have a 4500 lipo on my osd it said 179mahbut when I charge its put back in 570mah what should the scale be set at it would be help full for the numbers as my maths are shocking lol

[@JoshuaBardwell]

570 / 179 = 3.18 The number in the osd needs to go up. So the scale needs to go down. Divide the current scale by 3.18

[@gwizzfpv6741]

@@JoshuaBardwell thanks very much

[@serenityfpv]

Joshua Bardwell I am using your latest FC. I'm using the formula from the video, I land at 900mah as from the osd because my voltage is reading low enough that I have to land anyways at that voltage. I'm using RDQ 1500 lipos. At around 900mah from osd my volts are around 14.2 to 14.4 before I land and voltage goes back up when I land like it should. My question though is, I use 4 batteries. So 900 x 4 is 3600. I put back in on the charger around 5200!! So 5200 divide by 3600 is 1.44. So is there a baseline of 100% because yours was 0.894 I think so it's 10% high. If mine is 1.44 does that mean mine is 44% low or is it 54% high? I hope I'm explaining it right or you understand and I'm doing it right. Thanks for your time

[@serenityfpv]

Default value is 250 for your FC, and you increased the scale by 10 percent because osd is reading 10 percent high. In my case, the number I got is 1.44 so do I increase or decrease the scale? I've increased the number to decrease the scale and added 44 percent to 250 and got 360, is that right?

[@JoshuaBardwell]

You put back in 44% more than you took out, so your OSD is reading 44% low. To raise the OSD, lower the voltage scale. Multiply the voltage scale by 0.44.

[@serenityfpv]

@@JoshuaBardwell Thanks Josh, love your channel, and learning, :)

[@ericimtf]

I use the same method too, but i make sure after connecting lipo , i arm and straight away take off so that all mah will be registered. I do one lipo at a time, normally take three lipo to get accurate mah.

[@discord2000]

Dude the current sensing is happening as soon as you plug the battery in...

[@ericimtf]

discord2000 , i use virtual sensor on older quad where there are no current sensor. I can get approximate mah reading also.

[@anastaciapop4117]

What about using a power meter and making the current match the one you see on the power meter ? That's what I've done .

[@JoshuaBardwell]

That is very difficult to do since it requires spinning the motors with props on.

[@alexdalton7290]

Hey josh what would be a reasons for voltage monitoring to not be working seems to be wired correctly vcc Gnd to fc. Fc buzzer port to buzzer

[@JoshuaBardwell]

Is it enabled?

[@alexdalton7290]

Joshua Bardwell yea it is on in betaflight damn bro that's fast

[@JoshuaBardwell]

At the top of the configurator, it will show the current vBat value. What does it show when you plug in to USB and a battery at the same time?

[@pav2k]

Can I calibrate it with the clamps and the props off?

[@MatthewTaylor3]

There should be a documented list of calibration values for each current sensor.

[@JoshuaBardwell]

This info is available from the manufacturer sometimes, but even if you have it, the precision of the resistors is not high enough to guarantee accuracy based on nominal values.

[@taggerung890]

Is the voltage sensor always correct on FC boards?

[@JoshuaBardwell]

No. That's why you have the vbat scale in the Power and Battery tab to let you calibrate it.

[@AbdulAleemShekhani]

Just rewatched this to remind myself as I calibrate a new FC. Complaints: There was no juggling.

[@timsuzuki173]

My flight controller is reading the wrong number of battery cells. Any reasons why, and how to fix it?

[@JoshuaBardwell]

Go to the Power And Battery tab and raise the Max Voltage threshold from 4.3 to like 4.35 or 4.4.

[@RealKushrage]

Very nice method, thank you very much

[@JoshuaBardwell]

That small difference in voltage is probably no big deal. The 130 amp one doesn't necessarily generate more speed and acceleration. It might just be less efficient. For example, if you put a very heavy prop on a motor, and the motor doesn't have enough torque, the amp draw will go up but RPM won't go up.

[@RealKushrage]

Okay nice, thank you very much for your fast answer. I learn so much from you 😊and I appreciate it that you answer any of my dumb questions I probably wouldn’t even get my quad in the air without you🙈😂

[@swugger]

my problem is it doesn't even tell me how much mah I've drawn