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Upload this curve into the battery discharge curve. Note that the curve is for lg he2 cells. http://evolvapor.forumchitchat.com/file?id=2391339

Thanks John! You guys over there keep amazing me. Glad it was a quick fix. I'll get it loaded and verify operation today.

Before anything else goes up in smoke, how does this look?

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Does anyone have a discharge profile for dual LG 18650 HG2 with 3000 mAh and would like to share?

For now I've used the discharge graph for the HE2 and set 44.4 Wh (6 Ah * 7.4).

PS: Also thanks for the info in this thread! I was able to complete my first DNA 200 dual 18650 build - everything works perfectly!

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Are you sure the 44wh is correct dejay? I have those batteries and seen to remember then being in the 20's for wh but I could be mistaken. I don't have the proper discharge curve yet but I'm working on it ands I'll post it in a screen shot when it's done

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Right! Batteries in series don't double their mAh's lol. It should be 3 Ah * 7.4 = 22.2 Wh. My bad :D

But a battery profile fo the LG2 would still be nice. I don't think I can just use any atomizer to burn 20 watts for an hour. I guess I could use a long kanthal coil that is outside of the atomizer and connected to some kind of heat sink sitting in water.

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Jvape78 said:

I do have 1 issue left to resolve. I keep getting a weak battery alert on screen when my battery bar is 3/4 full still. . I plugged it into escribe and the picture here is the readout. Everything looks right. Cells 1&2 reading 3.8 and cell 3 is reading 1.25. I know they set the limit to 1.5v on cell 3 so I'm under that. . Only thing I can think of is maybe the tap connection at the battery tray is not perfect and if it jumps up over 1.5 it causes the chip to enter 3s mode and then thinks the battery is low on that 3rd cell. But it never gives the message when the batteries are fully fresh and you'd think a connection issues could cause the message to be seen at any time..any other thoughts before I warm up the soldering iron?

Were you able to resolve the issue?
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Mad scientist, where I'm at right now is I lowered the soft cell cutoff to 2.9 . I was out of town all weekend so I didn't bother trying to run down cells as I couldn't monitor them so I just swapped batteries at 50 percent and did not get any weak battery notifications like I normally would have when using my regular seasoned 25r batteries. So Monday (today)I put in the freshly charged seasoned set of 25r batteries and used it all day at 46 watts. I just now got the weak battery at about 90 percent drain on my meter. My meter is a hodge podge mix of the new hg3000mah watt hours with a discharge curve that of the lg he 2500's. So I have been more interested in hitting the soft cell cut off 2.9 and then measuring my cells regardless of the meter anyway. .when I pulled the set today after getting the weak battery they measured at about 3.5v so the sag is still very evident with those particular batteries. I'm putting in the fresh hg3000mah set right now so tomorrow evening I will have them run down and will be able to check them and I'll have the definitive answer as to the cause of the massive sag either being battery related or not. This has made notice the battery life in my other mods using these same batteries and I feel that in the end the batteries will end up being mostly to blame but we'll find out for sure tomorrow. ..

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Not the batteries! Something bogus happening elsewhere but today I ran the brand new freshly charged pair of hg3000 mah down until I got weak battery note (set at 2.9v). Plugged into escribe at that point and this is what I got. . 3.4v batteries sagging down to 2.9 is not right. Not only that but I noticed that some times it doesn't register any sag,sometimes both sag, and sometimes only one or the other sags. .. I used 18ga wire and it's less than 2 inches long so I shouldn't think it's wire size. ..I am at the point now where it seems to be clearly not my batteries or my wiring. .kinda only leaves one culprit.

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I'm no expert but I heard that battery sag is totally normal and that the voltage will recuperate if not under load. So you have to measure the battery voltage under load basically. So sagging from 3.4 to 2.9V doesn't seem strange to me. From my limited understanding it could be 

1. Bad battery contacts where voltage is dropped at contact resistance (try cleaning them)
2. Watt hours are not set correctly - the theoretical 22Wh of the LG HG2 is only under ideal circumstances and the real number is lower
3. Discharge curve ignores the watt hours - I'm not sure of the discharge curve is "scaled" with the watt hours you set. Not sure though. You could try and use "total Wh" in escribe 

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I had the same, low battery message when batteries were only just over half discharged, I ended up soldering an 18650 2s pack to try and same results. I turned my preheat down to the wattage I'm vaping at(around 45w) and now my batteries give me the message around 10-12% on the battery meter. I too have my cut off at 2.9v. I just need to lower the watt hours by 10% to have an accurate meter. Conclusion is that 2s 18650's just aren't man enough for this beast of a chip. If I want more power I just use my lipo dna 200, but just run tanks on the 2s mod.

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Yeah I kinda figured that may be the end result. Wish I had known to expect it instead of ripping the mod build apart at least 50 times, rewiring and configuring settings and such. Chip works flawless except for that. I have a cloud maker I had ordered back in July coming so there's my lipo if I need it. I also have a pre order for that new triple 18650 the realeux or whatever. That little dude is gonna rock with 3,3000 mah batteries so I'm good with my little boxer type version and it's dual battery software issues.running it at 50w or under, It runs my 25rs to about 3.6v and my new hg3000 to about 3.5. . They get me through a whole work day powering my cthulhu v2 with a dual 26ga titanium build of. 25 at 50w so I'm gonna call this issue laid to rest and it is what it is until (unless)evolv can fix it in a future update. I appreciate the help!

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Lol. .I wish. If you had a dual configured mod, you could plug it in to escribe and see what we who have them see, you'd understand it's no simple mah or curve setting. You can watch the voltage the cells get very erratic when they dip under 3.7 or so. I describe what they do a few posts above. No matter what you set your mah and curve at, it won't change the way the cells act below 3.7v.

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Like I said I'm no expert but I don't quite understand what your problem is. So I'm just trying to help and am curious:

So your problem is that you get the weak battery warning when both batteries show 3.8V? The other four pictures you posted show the cells at different voltages. But that could be explained by your battery voltage being 3.4V without load and it sags down to 2.9V under load (which is normal and near empty) - and that the display is simply not getting updated quickly and you made the snapshot. Either it is delayed or maybe some data transmission error? You could track it much better if you would check the cell voltages to graph and look what happens when firing. And if they are indeed erratic and different from each other. Then it might be a connectivity problem after all.

I do have a dual 18650 mod and haven't (yet) experienced any issues except that:
1. the battery meter is not accurate because I assume either my mAh or my battery profile is not correct for my LG HG2 and
2. I get "ohms too high" on a 0.3 ohm SS build at 100W when my voltage gets too low. But both of that is to be expected I guess.

Cheers

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I have 5 "married" sets of inexpensive 18650's and not one of them behaves as poorly as I've seen described in this thread. I set my home grown double 18650 DNA 200 mod to 2 cell, set the Wh to 17 and I can vape beyond when my battery meter reads 0% without any low battery message. I have preheat set to 100 W 1 second, punch 5, watts 75, temp between 450 and 490 as the mood suits me. These are the batteries: https://www.fasttech.com/products/2913000

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The last time i got a weak battery message, i connected to Escribe and Device Monitor to check out the battery status... resting voltage per cell was about 3.53v, but when i fire the mod it dropped to 3.2v and under and i have soft cut off set to 3.2v, so i figured this was normal battery sag due to the high Amps it was trying to pull running a Dual twisted TI coil setup @.08ohms at around 50w with 80w pre Heat and 6.5 punch.

I have seen similar on my EFusion 1300mAh lipo.. maybe not quite as much sag, but not a whole lot in it...

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  • 1 month later...

Just a quick clarification.. I am building a dual 18650 cell mod and with preliminary wiring done as stated in this discussion, in Escribe I get Cell 1 - 4.2v, Cell 2 - 4.2v and Cell 3 - 1.2v .. Does the third cell voltage have any significance and if so what is its range (or) its just a phantom voltage that is read and to be just ignored. Any inputs will be helpful..

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Hello, I've been looking and can't find a solid gauge suggestion for the balance tap wiring. It looks like on Mamu's dual 18650+RPP post she has it listed as 24AWG-26AWG. Although it looks like someone suggested 20AWG earlier in this thread. Can someone please point me to the right size. I'm hoping to find the suggested gauge not just min to max if at all possible. Thank you all in advance.

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  • 2 weeks later...

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