Lipo voltage monitoring in microquads

It’s been 4 months since i started in this hobby. So far i’ve accumulated maybe 20 different 1S batteries between 150 and 720 mah. The problem i found with tiny whoops (the ones i’ve been flying the most) is that i don’t have a way to reliable monitor battery voltage, at least with the beecore boards that i have. Recently i bought a multimeter and started to check voltages right after each flight and some minutes later. Battery voltage can easily drop below 3 volts if you just fly until it falls to the ground, and i know that’s no good. The result of this is that right now i have maybe 9 batteries a little bit puffed.

Many people just set a timer, but i don’t think that’s the best way to leave all batteries in a similar charge in order to charge them together. Now i’m building micros with 8520 motors, and with boards like the f3 evo you have the option to use buzzers for voltage monitoring. That’s the best method that i’ve found so far (at least the most cheap/light/effective method)

So, are there other tiny whoop boards that let you monitor battery voltage? Is there any way to monitor battery voltage in a beecore board? What do you think about? What methods do you use? How many batteries you’ve ruined before starting to use them properly?

After puffing two HVLi, I use a timer on my tx. A few seconds more 5-15 and I’m within .2v. Depending on how that flight went. Balls out, or crashing. I pause timer to right quad then start it again.
My experience with V monitoring was a PITA.
Voltage sag on high throttle was constantly sounding buzzer on larger H frame w Scisky. Wouldn’t waste the weight on anything smaller, and can’t see the lights flashing from FPV.
This little guy here once calibrated is what I use before charging to confirm voltage is within spread. The PH2 battery connects directly, The microJST batteries need an adapter. Just diy one.

2 x 2 in 1 Lipo Battery Low Voltage Tester 1S-8S Buzzer Alarm

Thanks for sharing

The alternative solution is OSD. FC with OSD can impress voltage on video image and, imho, this is the real unique useful feature of OSD in general.

Yeah, having on screen constant voltage monitoring sounds very nice. This should work great in my next 8520 brushed build, i’ve seen some boards with integrated osd, but still that’s not an option for a beecore tiny whoop.

Still have to do some research to figure out how to connect the osd to the camera, i don’t know if the cameras that i already own have some specific pads to solder the signal from an osd…

Thank you!

You might find this thread more helpful than I have been…
From @mmoore:
…“The reason for this post is to share what I found that might help anyone wanting to mod one of these little AIO camera/VTX modules to work with OSD.”

Ive bought a few things from hobbymate including 2 fcs don’t have osd one wired up yet but I am very happy with their products so far no problems or complaints

looks nice! thanks a lot for the info!

Just ordered this:

Not being eachine is possible that it works ok (most of the many eachine products that i ordered so far had some kind of problem) So let’s see if it flies well

That one looks promising
Keep us posted

i have ordered 2 of these 2 weeks ago.
Im in a fix trying to find a brushed board that will fly more than 4 batteries with no issues.
Most of the ones I’ve tried have satellite power and communication issues. (multiple new satellites tried)
Quality on eachine products has gone down in the race for new brushed/brushless FC.
Ive had at least 4 failures recently with eachine and BG sourced flight controllers.

I just want to have a 1s/dsm/buzzer enabled FC that is reliable and works.

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OSD sucks a lot of juice (the MAXxxxx chip they use for graphics is a power hog). This becomes a problem on 1S and puts a burden on stepups/stepdowns.

I also find it difficult to pay attention to the onscreen text.

I find that the timer method is by far the easiest, if not most foolproof method. Takes a while to get into the habit. But it works. I’m surprised how accurate it is. Once I figure out how much time I get from a battery, I land with the same voltage almost every time.

OSD is more useful for PID tuning and current monitoring (on big quads, where current draw can be a BIG problem)


Yeah… but not only with fc boards. It seems like they just don’t have quality control at all, and when you get a decent working product you’ve been just lucky. The e010c that i ordered had a dead battery. Ordered 3 sets of 5 batteries. In two of the sets there was one dead battery. Ordered two beecore boards, one doesn’t work 3 meters away from the transmitter, the other one flies wierd after flying a few batteries. The f3 fc board that i ordered lasted 4 batteries before a fet was damaged, In one of the aio cameras that i ordered the image is off center. The only product that works ok is the vr007 goggles

After reading this list i can’t recommend buying anything eachine. You can ask them and usually there’s no problem to get a replacement or a refund of the money, but they make you waste your time waiting for weeks, testing their products, recording videos showing the issue… I’m just fed up with them. I’ve bought lots and lots of parts and still don’t have a decent flying machine

Now i’ll try the osd integrated fc board, but maybe you’re right and setting a timer is the best solution… :confused: