I want to power my VTX and camera separately from the motors. How do I pick the right battery for this? Are amps or volts more important? If my VTX and camera each use 5V do I need a battery that puts out 10v? If I use a 600mW VTX do I need a 600mW battery? I appreciate your help.

If you have 5V VTX and camera, you need a 5V lipo (doesn't exist, see below) or battery. To calculate how big of a pack you need, you need to calculate how long you are going to fly against the amp draw. You should be able find how much mah each device uses.

For example, you have a VTX that draw 600mah. That means every 10 minutes, you are drawing 100ma. Since you only want to drain max of only 80% of capacity of a lipo pack, you want a 5v 125mah pack to fly 10 minutes.

Since lipo only come in increments of 3.6V, you will probably need a buck or BEC (voltage regulator) to provide 5V.

mW is not a spec for battery.

It would help to know what camera and VTX you are using, so we know the input voltage range.

(20-Jan-2019, 01:23 PM)Oscar Wrote: It would help to know what camera and VTX you are using, so we know the input voltage range.

OP mentioned that both camera and VTX take 5V.

Thanks everyone. This is a big help. I'm using a Lumenier TX5G6R Mini 600mW 5.8GHz FPV Transmitter and a Foxeer Predator Micro V3 camera. Any other advice now that you know the configuration? Also, can I use a 1S or 2S battery?

You are mistaken.

Your VTX takes 7-20V
Your camera takes 5-40V.

Not 5V.

You can get away 2S-4S not 1S.

How long are you planning on flying?

Thanks Voodoo. Let me see if I understand. So if the VTX takes a min of 7V and the camera a min of 5V then I need a min of 12V. If each 1S produces 3.8V then I need a 3S battery since a 2S would give me 7.6V? Or would the 7.6V just get drained faster?

No, you can't calculate 5V + 7V = 12V. Whatever voltage you have as the supply, it will provide that same voltage for both components. In your case, 5-40V cam and 7-20V vtx, you will need at least 7V supply to make it work.

If you use 2S, as the amp drain, the voltage will drop. You will get below 7V sooner and can cause a brownout. So if you use 3S, then the chance of brownout is less likely. Regardless of how many cells you use, if the lipo drops below 3.3v per cells, the voltage will drop rapidly. You will damage your lipo if you get below 3.0-3.2V per cell.

How much capacity you have is basic on the mah of your lipo.

I've got it now. Thanks voodoo. I really appreciate your help.