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2s 18650 discussion


John

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Mad Scientist said:

[QUOTE=Jvape78]I've been having a tough go at getting my chip to work properly in my build. I see that recommended wire size for the balancing tap wires is 20 GA or a bit bigger. .I bought a pre wired tap from my local rc store that uses 22 gauge. Could this be the reason I can't get my chip to stay powered on for more than 3 seconds? I know my wiring is correct and I've set chip to 2 cell and loaded the curve so I'm not understanding what the heck else I can do here. I didn't know if 22 gauge would be enough difference to cause this or not.

Can't be the wire gauge to the balance tap. Might be the way it's wired though. What does device manager report as the cell and pack voltages?[/QUOTE]

I don't know if you've already got your answer. But it so happened, that mine did the same thing. It turnes out, that out of the box, DNA200 comes programmed for three battery cells. When I connected two batteries, it would turn on but will turn off in about 3 seconds, After connecting it to Escribe and changing configuration to 2-Cell, everything went back to normal.
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  • 2 months later...
  • 3 weeks later...

It might be nice but why would they, it doesnt meet with my logical thought, i mean; i bought mine as 200 watt capable boards, and i realy cant get my head round designing and building a mod that houses 2x 18650 batteries, when a tripple cell lipo, doesnt fill much moor space,, If it where a cherrished box, fine engraved with mother of pearl or gold inlay and only a twoes would fit, faire enough, but i would still be saying shame ya couldnt get a tripple in there, nothing worse than running on half engin.. and back to the op, shame this thread never got locked because it has some realy good fault finding tips at the start.

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I understand why some would want a DNA200 and use only 2x18650. Most DNA200 use small capacity 3S lipos. A 900mah for example is only 9.99Wh. A 1300mah is only 14.43Wh. But just two 18650 2500mah is a whooping 18.5Wh. And with 18.5Wh means you will be able to vape longer per charge than the other two choices.

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So whats that 20% ?? Ok not getting too in depth or out of my depth, theoreticaly, possibly,,, but with either mod in hand, twin coiling throughout the day a flat battery at 3pm or flat at 4pm is why a lot of us carry 2, unless your me with a tray of back up devices backing up my back ups. and again its not my field to explain the performance of lipo over ni

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One thing that I like about 18650s is that you don't have to charge them in the device. Ok lipos you don't either. But most DNA lipo designs are not easy to pull out and install a battery. But most 18650 designs are. And if that is easy and 18650s are easy to get and cheap, why not have spares? Now charging is like 5 seconds. Sure you have to put the drained ones in an external charger. But you don't need them anyway since you already have a set installed at full charge.

Another annoying thing about 3S lipos is sooner or later, one cell is going to fail. Strangely enough, the other two are usually just fine with plenty of capacity. But now you have to buy another 3S lipo anyway. On a 18650 equipped DNA200, you can change out any cell and keep the other two (or one) good ones. Okay not a good idea mixing old with new 18650s (but in an emergency it is doable), so the smart move is to replace all of them. But you still have a good 18650 or two that you can use for something else.

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I cant put an arguement up because i aint built one, but to be perfectly straight i have three twin cell lipol batteries at 1200 mah 8:88 Wh measuring 68mm x 33mm x 4mm at 7:4 volt, i would be keen to use them if possible. But simply because i think i could get them squeezed as a parallal pair into a strepcil tin, and also these tins are or have a slight indented face and back so i could polish it then inlay a bit of timber veneer i have.

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I did somthing of simular size in a hammond for someone but with a dna 30 clone, i'll edit the post with a picture of the tin and batteries when i get to a computer,, unfortunatly the tin has seen better days but it would be a nice bit of fun mod with a disstrest look and paired up with a little dripper and nanno coils like a hobo or brass monkey or even a mini rtda like a goblin, a 3ml aromatizer might look a bit posh for it, lol, pic to follow...


bacca_tin.jpg  i only vape myselfe on avarage 11watt on a sigle coil rta all day vape and 30ish watt on a twin coil rdta, and at this moment im using a twin coil goblin mini on :30guage loose twisted kanthal, and 18 watts is all it needs with 1:50mm coils at :46 ohm, so a 3ml tank would marry up nice to a little battery mod, old tobbacco tin.. blar dee blar ect lol..

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This came up elsewhere, but thought I should also put it in this thread.

Kanthal limits from R = P/I.I = V.V/P
(I think if you want to convert to temp limiting numbers you would use to the hot resistance to match to a row on this table, not 100% sure I will run the numbers with Ni sometime to check.)
R_limits.png

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thanks for that, plenty of time to get my head round it,,,
the kantal thing I was on about was pretty much a one off but worked well, stuck for time with a back log of attys piling up waiting to be cleaned and rebuilt, I am very much tc, (for the miles of ni200 and nife30 on the bench) but stuck for time last night I resurrected a little rdta and threw it together with some, I suppose  macro coils , a bit of resistance with kanthal,   found it was way to hot and out of control on a mech mod, also resurrected,
I should think we all get a little set in ones ways when having a few mods and attys collecting, that we build to the atty on that particular mod and don't divert to much, , I had almost forgotten the benefits of simple wattage control through the dna200,,, anyway, got a decent vape within minutes and haven't put it down all day.

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  • 2 weeks later...

Okay in 2s mode does it work well for temp control? Or do I need the full 200 watts. I was using the crown tank with the .25 coil and at 80 watts it was a nice vape. But with this .15 nickel coil, temp control doesnt seem to appeal too much. I have the preheat at 133 watts. Punch at 11. Timeout at 1.5 sec. Watts are set at 80 watts and temp at 520. Seems rather weak. Like the heat and clouds like the .25 coil instead.

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badow24 said:

Okay in 2s mode does it work well for temp control? Or do I need the full 200 watts. I was using the crown tank with the .25 coil and at 80 watts it was a nice vape. But with this .15 nickel coil, temp control doesnt seem to appeal too much. I have the preheat at 133 watts. Punch at 11. Timeout at 1.5 sec. Watts are set at 80 watts and temp at 520. Seems rather weak. Like the heat and clouds like the .25 coil instead.


It works just as well, it is just the max resistance is lower than for 200 W operation and obviously the 200 W limit.  I can't see it being a big problem unless you want to use pre-made coils above about 0.3 ohms when hot at higher power levels.
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Hope I'm posting in the right area here... I got my Efusion DUO 133 w two days ago and I am trying to get a grip on how to set this thing up. I have 2 imren 18650 3.7v 3200MAH batteries in it, set the battery section of ESCRIBE to LiPo at 28.63 WH and the soft cutoff is at 2.8v, is that right? I'm not sure what a soft cutoff is... Sorry if that's a dumb question . Also, battery one is showing at lower volts during usage and while charging than battery two. 1)3.66 2)4.15 Is this normal? I attached a picture of what I'm seeing. I'm really just wanting to make sure I can vape this thing safely, and that my batteries are correct and my meter is displaying correct. I don't care about changing everything and personalization. At 50 years old I'm not tech savvy at all. Also when I charge the batteries it stops at about 51%, not sure what that's about? If anyone can help me I would be so greatful.

IMAG0319.jpg

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Klnco4 the watt hours should be 23.68 (21 or 22 would probably be more realistic) and the soft cut off & LiPo are fine, but I would get both 18650 charged to the same level then if after some usage they are a significantly different levels, charge them to the same level and swap their positions to see if it is a weak battery or 1 battery position is reporting a low battery (far less likely).

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VapingBad said:

Klnco4 the watt hours should be 23.68 (21 or 22 would probably be more realistic) and the soft cut off & LiPo are fine, but I would get both 18650 charged to the same level then if after some usage they are a significantly different levels, charge them to the same level and swap their positions to see if it is a weak battery or 1 battery position is reporting a low battery (far less likely).

Thank you for that advice. Will changing to watt hours make the meter more precise? I'm still puzzled as to why it would stop at 50%
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Not an expert on those but if theres a voltage cut off limit it will do just that, two 18650s connected in series would be putting out 7.4 volt, so as they run down the output gets lower, if there isnt a default set cut off limit the batteries will become unstable, volatile, rather perturbed, lol .. I have built a few twin 3.7 volt mods on the dna 40s and the meter goes up and down on initial start up as the batteries sink with each outher. But again in your case i think it is your voltage cut off limit. Brand new batteries and keep them as a maried pair would be beneficial,, quality ones like sony vtc4s or greater..

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Klnco4 said:

Thank you for that advice. Will changing to watt hours make the meter more precise? I'm still puzzled as to why it would stop at 50%



Yes the watt hours are just there for more accurate battery metre, it is similar to mobile phones and more accurate if you charge the batteries in the device.  Nothing to worry about, I use 3 sets of VTC4s in my rolo, with 2 sets the metre is spot on, but with the 3rd it goes to empty a bit early. The important thin is it warns me that I should have a set ready to go in and it does that fine.
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black lace said:

Not an expert on those but if theres a voltage cut off limit it will do just that, two 18650s connected in series would be putting out 7.4 volt, so as they run down the output gets lower, if there isnt a default set cut off limit the batteries will become unstable, volatile, rather perturbed, lol .. I have built a few twin 3.7 volt mods on the dna 40s and the meter goes up and down on initial start up as the batteries sink with each outher. But again in your case i think it is your voltage cut off limit. Brand new batteries and keep them as a maried pair would be beneficial,, quality ones like sony vtc4s or greater..

So I should get some new batteries? In Escribe there is a soft cut off limit set at 2.8...
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  • 6 months later...

Hello! I just bougt a dna250 chip and i run in to some problems, I dont really understand how im gonna solder this becuse i see alot of diffrent types of wiring diagrams here, So if anyone could help me get the correct diagram for me i would be really thankfull, i have solder the tap to the board cuz i prefer to solder on the tap and not on the board, but now im stuck do anyone have a wiring diagram that works for 2 18650? Sincerly bad english writer from sweden that only have done unregelated before...

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