bmclaurin

Lithium-based cells do not need a "forming" or conditioning charge like nickel-based cells do.

I will defer to James if he really said that, but this should not be true. It is a fundamental and unavoidable characteristic of the chemistry of lithium-based cells that capacity declines as the rate of discharge increases. EDIT: I will admit, however, that running the analyzer at 100w versus 50w won't have a huge impact on the results, but the difference would certainly be measurable.

tageeboy, is your fuse blown? I couldn't tell from your post, but it sounds like it might be. See page 10 of this pdf for location of fuse and what a blown fuse looks like. http://www.evolvapor.com/datasheet/dna200.pdf

stuartro, seems to me it should work precisely the way you've described it. And I could have sworn that was the way it used to work on earlier firmware. But, lo and behold, I just tried it on my device (with latest firmware) and it doesn't seem to lock the value specified in the profile.

Looking again at the graphs you posted kinda reinforces my belief that something is awry with the build. The differential between the live and cold ohms on the Titanium graphs points strongly in that direction. I have a strong suspicion that one or both of the coil legs is not getting a good connection to the post. Or there is a weak spot in the coil (a crimp from a slight bend perhaps?) that is causing the resistance to surge when power is applied. Hang in there, man. You'll get it sorted. And when you do, you're gonna be in for a treat. This chip is a whole new level.

From what I'm seeing, I'm betting it's the build (or you're somehow not uploading the .csv profile correctly), not the chip or the mod. I know you're beating your head against a wall with this, but the fact that your nickel wire is performing fine indicates to me that the chip and mod are doing their job properly. Not sure what else to suggest except checking (again) the integrity of your coil. I guess one last thing to check is your ohm lock range setting--is it detecting that you're attaching a new coil? Are you getting the "new coil?" prompt?

So we're talking single coil, I presume from those ohm readings? What are your preheat settings? Also, I'm sure you've triple checked this, but you're certain you've selected the correct profile on the box (the one to which you uploaded the .csv profile)?

Also, are you heating your coils some before wicking? I know most people say not to do this with Titanium, but I do it with all my titanium build, albeit at very low wattage. For my builds, a setting of about 10-15 watts in Power mode is just about right to warm them up ever so slightly. About a 5-second pulse on the fire button will cause the coils to slowly warm up to a very dull, dim reddish color (and I find I usually have to turn the lights off to see it clearly). This is good at helping spot any problems like hot leads or whatever. Obviously, you don't want to fire it a high power and turn the coils bright orange, so keep the power low for this.

I'm using SSV Ti 0.4mm and 0.5mm with very good results on a Lavabox DNA 200. Just curious what builds and atty you are using. I'm mainly doing standard dual spaced coils (but have done a few contact coils as well) in the 0.10-0.15 ohm range. I have noticed that titanium wire is fairly sensitive to making optimum contact with your posts. For a few of my builds, I doubled back the legs in each post to give the screws some extra material to grab, and that seemed to help.

That is very unfortunate. You could always buy a new pack. Really sucks that you would have to do that, but the device itself is likely fine. I would not attempt to revive your existing pack, as it will likely cause the cells to become unstable.

Setting it at 3.8v is way too high. It won't do any harm, but that's like buying a car with a 20-gallon tank and putting a chip in it that won't allow it to use the last 10 gallons of gas left in the tank. :/ The LVC is a compromise between runtime and longevity. For RC, particularly when you're using 14S 5000 mah packs that cost $200+, you're taking a bigger (but calculated) risk with a low-ish LVC's, which is why most RC'ers (myself included) like to consume no more than ~80% of the pack's actual capacity. But with much less expensive packs that are suitable for vaping, I am perfectly comfortable sacrificing a small amount of longevity for some extra runtime. The eVolv default of 3.09v is a good compromise IMO. But if you're concerned with that and want to preserve some more longevity from your packs, raise it up a bit, but maybe to around 3.2-3.3v (or even 3.4v if you're so inclined), not anything nearly as high as 3.8v IMO.

How does the on-board battery meter determine estimated remaining battery capacity? I am very familiar with state-of-charge (SoC) curves (like the .csv files that are uploaded in eScribe) and methods of determining pack capacity (like eScribe's Battery Analyzer tool). I have used those tools to determine my pack's capacity, entered that into eScribe, and have uploaded the resulting .csv file to my device). I'm just intellectually curious how the on-board battery meter uses this information to determine my pack's estimated remaining capacity percentage. Originally, I was just thinking that it simply measured the resting voltage of my pack and interpolated the capacity % from a lookup in the .csv table. But somehow I suspect it's not quite that simple in reality. If it was really that simple, then it wouldn't matter what value I entered into the pack capacity field in eScribe (since it could derive an estimate based solely on voltage directly from the .csv table). I'm now thinking that it works something like this: 1. At the completion of each and every charging session (whether fully charged or not), the chip measures the pack's resting voltage and makes an initial determination of capacity % from a lookup/interpolation of the .csv table. 2. It multiplies that % by the total pack capacity (as entered in eScribe) to determine an estimate of how many watt-hours (Wh) are available in the pack immediately after the conclusion of the charging session. 3. From that point forward, starting as soon as the battery comes off the charger, the chip measures how much capacity has been drawn from the battery and subtracts that from the initial estimate of capacity determined in step 2. 4. The resulting remaining capacity (in Wh) determined in Step 3 is then divided by the total pack capacity (as entered in eScribe) to determine estimated % capacity remaining. 5. That % is then displayed on the chip's screen. Now, I doubt I have this exactly right. There is probably more going on here. But that's how I have it sorted in my mind at the moment. Can anyone comment on whether this is how it really works? It doesn't really matter at the end of the day. I'm just intellectually curious. I like to know how things work. Thanks.

Gosh, I hate to say it, but that pack is almost certainly toast. In fact, if one cell is really 0.3v, I wouldn't attempt to charge it.

I wish I could help, but other than suggesting that you run the battery analyzer like you've already said you intend to do, I'm not sure what else to add. It's unclear to me how the Wh setting in escribe influences the on-board battery meter (since it only indicates capacity as a percentage, which can be derived directly from the discharge curve .csv using only the battery's resting voltage). But running the battery analyzer for yourself will give you the best measure of your pack's actual capacity. When running it, I suggest running it at a power setting that is representative of your typical vaping style, and set the LVC to a level that is satisfactory to you (evolv's default 3.09v is a good place to start IMO).

Lol, yes, I forgot about you lucky folks with monster capacity batteries. Meanwhile, I'm stuck with the stock 10 Wh stock battery in the Lavabox. For that battery, at 3.5v it is literally just a few puffs. I checked my .csv to verify.

@vapealone, my apologies, as I think I read your first post and reply too quickly and missed your main point and proceeded to yammer on about trivial stuff that wasn't responsive to your idea. Yes, for a given LVC, the terminal resting voltage of the depleted pack depends on the rate at which the pack was discharged. At relatively low discharge rates, the terminal resting voltage will be lower as compared to what it would be at higher discharge rates, just as you describe, due to the aforementioned voltage drop. For that reason, I understand the conceptual appeal of a more customizable LVC feature that would allow compensation for differing rates of discharge. You are spot on in that regard, IMO. I will point out, though, that when you get down to the 3.5v range (resting), you're not doing much more vaping at any power setting without a recharge. Even at low power settings, you're only going to get a small handful more puffs before the pack is depleted. So the quality of the vape will only be impacted on those last few puffs. I hope I didn't come across as being dismissive of your feature request, as I do understand its conceptual appeal.

Also, once the battery gets to the point that it cannot sustain the requested load (at your specified LVC), the DNA 200 will dynamically throttle the power output to whatever load the battery can sustain (down to no less than 5W continuous) in order to optimize the capacity of the pack, albeit at reduced power output. John posted about this a while back, but I can't find the post at the moment. But, frankly, once you're at that point, most of the pack's capacity is gone anyway. We're only talking about a difference of maybe a small handful of puffs.

All of what you say is true. But... The curve generated by the battery analyzer is resting voltage, not voltage under load. The analyzer unloads the battery every few seconds, allows voltage to stabilize, and then records the resting voltage. If you click the "Record" button at the start of the test, you will get a much larger .csv file that includes literally thousands of data points (many samples per second) of cell voltage and power output (basically, the raw data that is shown in the live graph while the test is running). And you can readily determine from comparing that data to the discharge profile .csv file that the latter is comprised of *resting* voltage. Voltage sag under load is just the allocation of the total voltage potential of the voltage source (the battery in our case) to all resistors in the circuit, one of which being the internal resistance (IR) of the battery itself, and the allocation is proportional to the resistance. In our case, the total voltage potential is divided primarily amongst (i) the external load (the atty/coil/mod) and (ii) the IR of the battery. And the higher the resistance of the external load (the atty/coil/mod) relative to the battery's IR, the higher proportion of the battery's total voltage potential that will be applied to the external load. The rest of the voltage potential is applied to the other resistor in the circuit (the IR of the battery itself). When we talk about "voltage sag," we are talking about the voltage potential across the *external* load relative to the total open-circuit voltage potential of the battery. The higher the resistance of the external load relative to the IR of the battery, the less "voltage sag" will occur, since proportionally more of the total voltage potential is allocated to the external load.

I hear what you're saying, but if your motivation for this feature is to somehow extract even more capacity from your battery, then this isn't going to help much, if at all. Sorry if I misunderstood your intention or motivation. But the capacity of lithium-based cells simply doesn't advance much at all past about 3.3v, particularly at the discharge rates that are typical for vaping. You would be significantly sacrificing longevity of your cells for a very minimal gain in capacity. Whether that trade off is worth it is up to you, but IMO it is not. This typical lithium cell discharge curve, which I grabbed from a quick Google image search, makes my point better than my own words.

Yes, put those numbers in there, and even if you never run any of the analyzers, it will be one of the best vapes you've ever had.

Yeah, this bugged me too. I saw at least a couple reviews that said the device supported 2a charging, and that was one of the reasons I chose this model. Makes me wonder if maybe the pre-release versions supported it, but maybe it was scrapped for some reason?

You may be aware that you can display a percentage in one of the three smaller fields. Not sure if that solves your issue or not, but just letting you know it's there in case you didn't realize it.

No problem on the questions at all. I actually like discussing this stuff. I really just mean that the curve is optimized for 50 watts output power. It will still be reasonably accurate at differing discharge rates. I chose to run the test at 50w because that is the power setting at which I typically (on average, if you will) vape most of my atty's.

My fire button tends to stick if not pressed in the center, which is both frustrating and potentially dangerous. The tinted screen window also tends to scratch up a bit from routine use, but that's no big deal to me. The only other thing that I've noticed so far (and this is something I was well aware of before I bought it) is that the battery life is disappointing; and although I really like the size and form factor of the device, it doesn't allow much flexibility for fitting larger capacity Lipo packs.

I wouldn't worry about the charge termination voltage at 4.21v. To be clear, though, this .csv file is simply the discharge curve for the Lavabox's stock Lipo pack. It should have no effect on temp readings and such. What it will do is give you a more accurate estimate of the pack's state of charge, assuming your pack has the same actual capacity as mine (and no two packs are identical in this regard), you are firing your atty at or around 50w, and your soft cell cutoff voltage is set to 3.09v (since these are the parameters I used for this test).