Incorrect battery voltage

Well, now the radio is bound… I’m edging closer. BUT Betaflight wont get the battery voltage right. I’ve tried a 3s, it reads 4.8v. AND it doesnt even think anything is connected so I can’t calibrate it.
I stuck a 2cell Li ion on it and it claimed it was a 1 cell, but did at least recognise something was plugged in - I hot part way through the calibration, but the ‘calibrate’ button was unresponsive.
Maybe its a bluetooth thing…?

Don’t know what to do next.

What flight controller are you using?

Ahhhh… should have said! Its a Speedybee V405 v3 50amp.

Maybe i should try somesort of factory reset… I understand I’ll lose the settings I’ve added. But will it retain all the PID settings?

Plug it into BF and change the options in the ‘Power and Battery’ tab. If you fly 3S give it max and min values for a 3S battery. make sure the voltage meter source isn’t set to something random.

Thanks dude, ill try that. What should the voltage meter source be set to?

General rule of thumb is pretty much:

4.2V = 1S
8.4V = 2S
12.6V = 3S
16.8V= 4S

I would set max voltage to 12.6V and min voltage to 10.5V with a warning voltage of 11.1V, which would give (after landing) a resting voltage of about 11.1V - 11.4V.

I tend to always use the 1S average OSD element (it’s easier to work out voltages with 1S values instead of remembering all the different voltages for each size pack) and start at 4.2V and land at 3.5V with the final resting voltage being about 3.7-3.8V, but after watching a Mr Steele video, he says to land at 3.7V for a final resting voltage of 4V (or roundabout that level). The difference is he hammers his Lipos and they last him about six months. For us non-pro pilots, our lipos last a year or two. So I will go with the land at 3.5V for mine. What you do is up to you. The upside of landing at 3.5V is your Lipos will be at storage voltage levels, so no need to balance them to storage voltage.

On 1S whoops I go even lower and land at 3.2V, with a resting voltage of 3.5V.

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Thanks so much for your help. I’ve fiddled with voltage settings, and the scale, multiplier and dividers. Aaaaaand everything works again!

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Just remember if you set the battery voltage manually and say use a different size battery, ie, set to 3S and then plugin a 4S, it will scream low battery or Land Now. It’s really only useful if you have say a 2S or 3S that only ever runs that sort of battery. Or if you use say a 2S 850mAh Lipo always as your battery on a build, then you can set the voltage to 2S and the mAh to 850 to get a pretty accurate idea of usage.

BF recognizes the number of cells (1s/2s/3s…) based on the values you input for a single cell. You should only need to put the values of a single normal cell or HV cell, BF does the rest in regards to the size you are actually using (calculations are based on the values we input).
For a recent reference of this, you can check Bardwell’s “Power and Battery” video on his BF 4.3 series of videos.

Hmmmm… so if I’ve messed around with scales, dividers and multipliers - will it still recognise batteries wirh different voltages?

I would just leave those with the recommended stock values. Usually you can check what those are on the product page of the FC…

Thanks for help everyone. I’ve realised what happened… in a blind Betaflight panic, I just pressed too many buttons, and slid too many sliders. All has now been restored.
Also just successfully fitted and configured a BN220 GPS. Slowly getting there - one day soon this thing will fly!

Thats good news then…
We are always learning, this hobby has so much details that one can easily get lost at times. But nothing better than tinkering away and overcoming the obstacles…

Indeed, the learning curve is steep!

Its really only accessible to those who can focus to obsessive levels, or blow a fortune on a DJI (which is of course a very different beast!)

Very true indeed. This is ideal for the rabbit hole seekers for sure…

On my M75 the mAh displayed is skewed heavily. i still haven’t worked out the correct setting. I also don’t use the mAh or voltage fields. I tend to just use the 1S element on the OSD. but it would be nice if the mAh element was correct, since I know my Lipos are generally 1S 300 or 450 and if it gave me a more accurate readout it would be easier to work out how much juice i’ve used when flying.

To be honest, I dont have the habit of looking the mAh, only voltage, so I have no idea if my values are correct for those. I know that for the voltage they usually since I can check what its shows on the charger when I plug them in.

Having said that, I think that I have read somewhere, at some point , that the betafpv FC for the Meteor (not the latest version with the serial ELRS), might not read the mAh at all… Don’t know, might be mixing up information something else, but might be worth checking if there are any limitations is this regard for this specific FC.