dwcraig1

I would say there may be some resistance in the path of the power from the cell to the board. I say that because you said that you tried higher current cells. You have to have the power availible.

The voltage dropped to 3.1 but it still didn't hit the software cutoff

Here's my 80 back to normal. This is just an example of voltage drop where the device has resonably good connection between battery and board. This mod uses a chassis ground for all grounds. That's 4.13 volts on the cell to start, fires to 45 watts and drops to 35 watts. For comparision here is a DNA60C with LiPo, note only slightly better voltage drop.

There's a whole lot of folks don't get it about amp draw from the battery vs amp output from the board

Better results for sure. The data sheet for the 80 says 30 amp output and max 9 volts. snippets came from here: https://www.the12volt.com/ohm/ohms-law-calculators.asp Voltage to the atomizer, not voltage from the battery.

With a regulated device coil resistance isn't going to make any difference as long as it is in the range that the board is designed to operate. Unlike a mecanical mod where you run straight off the battery. Its the wattage to be considered.

I'll just say this: if you want a chain to lift 100 lbs. you choose a chain that can handle 200 lbs. Also today I tested my DNA100C at 80 watts using the same model cell. Standing voltage on the cell was 4.1 volts. Upon firing the voltage drop was 3.31 volts. On this mod though the Cell Soft Cutoff is set to the default setting of 2.75 volts. 'I have created a ticket with Evolv asking why the 80's CSC is set so high. It's not adjustable in EScribe and done via firmware.

So there is a problem with my comparision device, it is an early test board and is unable to run the latest firmware so the Cell Soft Cutoff is 3.25 volts while yours is 3 volts But for all other intents and purposes they are the same. Note if my cuttoff was 3 volts it would have done the 80 watts at that cell voltage. But not for long. I got throttled to 75 watts on the first on and 72 on the 2nd.

I'm in the middle of testing my DNA80C boro mod. I'm running the battery down to where I get the "Weak Battery" message then I'll remove the cell and measure it's standing voltage. Then I'll put it back in and turn of charging and get an idea what the Cell Soft Cutoff voltage is. But I can see the cutoff on yours, it's 3 v. I'm using a Samsung 20s 30 amp 18650. Here's where I'm at with it. The standing battery voltage right now is 3.54v, it is still hitting strong, no throttling yet. I have it set to 35 watt with a boost of 2 so it is starting to fire at 45 watts. Once I get the weak battery message and measure it I'll charge it to 3.81v and crank it up to 80 watts and compare results. My build is not designed for 80 watts but there should be no problem getting 6 fires from it, I'll just rebuild it when done.

Your battery cells are so low that they can not be safely charged. Looks to be 18650s so an easy fix. Replace them. Probably why the screen doesn't work as well. Charging is suspended if a cell is under 2,5 volts.

That is the default Evolv theme. Connect to EScribe, go to themes, save your existing theme if desired and select default theme and upload to device.

I can't hurt, go ahead

I have a problem. I have here a brand new DNA250 board and am doing the test that I suggested and am getting nothing but a ?. Hold on. No don't resolder.

I doubt if it started out defective. In the past Evolv was very sympathetic towards the hobbyist. you could be the cause of screwing it up and they would still replace it. The board being overheated during soldering is defiantly a possibility. Shorting between the output and ground would have produced a situation where the question mark and ohms readings would fluctuate back and forth as you where making a connection. You might want to repeat that process again just to be sure. Then there's still the problem with your battery cell #4, I'll save the fix for that till after the above problem is addressed.

I would say defective board then. Could have been defective from the start or possibly from excessive heat from soldering. Open a ticket here with Evolv: https://helpdesk.evolvapor.com/index.php?a=add&category=1 I suspect they will replace it for you.