If using 3s what do I need?

[Jdmagoo]

I plan to build an FPV quad 250 size that will run on 3S, however I understand the M4 is only 1s. So if I use a BEC to step down to 1s then how does the m4 know what voltage is remaining in the battery?

[JussiH]

Basically you need an expansion board. I have one coming up in january, but Joerg makes one as well:

viewtopic.php?f=25&t=3950

viewtopic.php?f=40&t=3857

If using a V2 board (think I saw one for you in the pile today), you could also do it with a Kisssys expander and a simple 5V BEC since the V2 has the Voltage divider used for battery monitoring and option to supply directly from 5V.

If using a V1 (beta) board, its a bit different and you will need to supply max 4.5V onto Vcom+ and use a external Voltage divider to monitor the main pack.

But take a look at Joergs board. Its very nice and perhaps he can get you one....

I will update the Docu shortly with information about how to use voltage dividers and >1s supplies on V1 and V2 boards.

[Jdmagoo]

[mumba]

Hi,

Did i understand right that the V2 board has voltage divider onboard? So i can put directly 3s lipo to ADC Port for voltage monitoring?

Thanks

[Astudillo]