dwcraig1

The DNA75 max voltage is 6.2 volts. On a 250C with two cells max voltage seems to be the voltage of the cells under load. On a DNA250 with two cells max is 6.2 volts. On DNA200 with 2 cells max is 6 volts. 6.1 volts @ 1.3 ohm on a 2 cell DNA250C should be no problem.

I believe that you trouble shot it well and as you probably figure it's most likely a bad board. They are real good about taking good care of their customers.

I'd say it's time for a new battery.

Are the voltage readings during firing or at Idle. Also instead of posting battery percentage it would be better to post standing voltage as percentage is just an estimate. But it's the voltage during firing that I'm interested in. In my snip where the red arrow is pointing it says 3.47 volts when I hoover my mouse there. This is firing at 45 watts for 1 second then 35 watts on single 18650.

Using Device Monitor as pictured above note the voltage drop on each cell when firing. Your Cell Soft Cutoff by default is 3.09 volts. If one ore more cells drop below that it will throttle down. They should drop reasonably close to each other. If one is way off then most likely a bad battery. Is the pack swollen at all? If your Cell Soft Cutoff is set way higher consider setting it to 3.09 volt area.

Using Device Monitor in EScribe check the voltage on each cell and post here.

You didn't mention what the wire material is, if TC wire resistance when heated is going to be higher yet. I'd guess that you are hitting the maximum voltage output of the board.

This is a 166 but I would think it would be very similar. https://www.youtube.com/watch?v=srfY6uQxSw0

Any chance that the 510's positive wire is making contact with the battery sled's positive contact? Does the Profile Unity have a slightly longer 510?

Have you charged your battery since taking this screen, it's pretty low? For round cells I set my Soft Cell Cutoff at 2.75 volts. Does it work OK when in wattage mode?

With a live screen hoover your mouse on the batteries voltage drop and post what voltage it reads. Also post what your Cell Soft Cutoff is set to. Edit: I'm thinking that your voltage drop might be lower than your Cell Soft Cutoff.

It's pulling 24 amps from the board not the batteries. Example: the pack @ 11.1 volts w/30 amps powers the board to put out 55 amps @ 4 volts (just a rough example, not exact figures)

Turnigy NE-BA931 will fit it just fine, this battery is rated at 750 mAh. That happens to all of them eventually. https://hobbyking.com/en_us/turnigy-nano-tech-750mah-1s-35-70c-lipo-pack-fits-nine-eagles-solo-pro-180.html

Which board? If a DNA60 it's not there.

Looks good to me. Did you use the same wire as the one with the problem?