Evolv DNA Forum
Sign up Calendar Latest Topics
 
 
 


Reply
  Author   Comment   Page 1 of 16      1   2   3   4   Next   »
John

Avatar / Picture

Administrator
Registered:
Posts: 500
Reply with quote  #1 
I'm making a new thread for discussion and testing of the new support for 2s batteries here. The firmware update to allow it should be posted shortly. 

To use 2s mode, you have to make taps from the battery as usual, but because there is no third cell, the tap connection labelled 3 must be connected directly to the tap connection labelled 2. This can be done in the wire harness or by jumpering the connections directly on the board. This is the ONLY way that 2s batteries will work and balance correctly. 

Other than that, it is just a matter of selecting 2 cell rather than 3 cell in the battery section. 

You can use 2 cells with lipos, LiFePO4 or cylindrical lithium ion. 

The max power and max preheat are 133 watts when running from 2 cells.

Attached is a battery curve for a 2s pack of  LG 18650 HE2 cells. This is probably a good starting point for high drain 18650s. The measured capacity was 15.5 watt hours.

 
Attached Files
zip LG18650HE2.zip (363 Bytes, 1061 views)

VapingBad

Avatar / Picture

Administrator
Registered:
Posts: 2,449
Reply with quote  #2 
John I know it is a bit early to ask, but will you be making a 2S RBP module for this as well as the planned 3S one?   I imaging the 3S one could do both assuming it is just a PCB.
__________________
• I am not employed by nor do I represent Evolv Inc.  All opinions are my own, they are just opinion not fact and can be wrong •

Latest versions of EScribe: DNA 200/250DNA 75
Common problems
John

Avatar / Picture

Administrator
Registered:
Posts: 500
Reply with quote  #3 
Yes, absolutely plan to. We see 2s replaceable battery mods being more common than 3s replaceable, just due to form factor. 
VapingBad

Avatar / Picture

Administrator
Registered:
Posts: 2,449
Reply with quote  #4 
[thumb] might have to get another board for those 20 25R & 10 VTC4s I have.
__________________
• I am not employed by nor do I represent Evolv Inc.  All opinions are my own, they are just opinion not fact and can be wrong •

Latest versions of EScribe: DNA 200/250DNA 75
Common problems
Dejay

Member
Registered:
Posts: 44
Reply with quote  #5 
Oh this is awesome! I was wondering the other day if this was possible! This removes one of my main downsides for the DNA200 for people who like externally charged batteries. Thanks evolv!
Dejay

Member
Registered:
Posts: 44
Reply with quote  #6 
Will the 2s pack 8.4V option affect the minimum resistance that you can fire nickel coils?
John

Avatar / Picture

Administrator
Registered:
Posts: 500
Reply with quote  #7 
Minimum, no. Maximum, yes. 
Dejay

Member
Registered:
Posts: 44
Reply with quote  #8 
Thanks! Makes sense I guess. 
John

Avatar / Picture

Administrator
Registered:
Posts: 500
Reply with quote  #9 
Well, with a 2s pack the max output voltage is 6.0V

The max output current is still 50A


turbocad6

Senior Member
Registered:
Posts: 153
Reply with quote  #10 
would it be possible to select between 2s & 3s mode right from the mod? I'm guessing auto detecting 2s vs 3s can't be done? my thoughts are, now I'm using a 3 cell configuration and the mod isn't too thick for everyday use, but I could make an extended use pack that's a 2s2p and add 25% battery life as an extended battery option, and of course have an extended battery door to match. kinda like an extended battery in a cell phone type design. having to change config in the pc isn't so bad but it would be really slick if it could be selected from the mod itself for on the fly switching too and from an extended use battery.
adski

Avatar / Picture

Member
Registered:
Posts: 37
Reply with quote  #11 
Can we use 2 18650's in series with no balance charger connected?
Just use the USB for software only?
Thanks
John

Avatar / Picture

Administrator
Registered:
Posts: 500
Reply with quote  #12 
No, you have to run taps to the battery. Why destroy batteries to save two minutes of wiring?
alee132

Senior Member
Registered:
Posts: 112
Reply with quote  #13 
Quote:
Originally Posted by Dejay
Oh this is awesome! I was wondering the other day if this was possible! This removes one of my main downsides for the DNA200 for people who like externally charged batteries. Thanks evolv!


I wonder how if you have taps running to them will you be externally charging them? Or can you just have taps running to the correct places on a battery tray instead of directly to battery's?  That would be epic. Infact I don't see why not.  This will make some of the people that were complaining about not being able to use 2 18650's happy. But I don't really see the point for 2s lipos now that I have looked at them vs 3s lipo's. So mainly this only makes sense for 18650's or 26650's imo.
John

Avatar / Picture

Administrator
Registered:
Posts: 500
Reply with quote  #14 
Exactly. You tap the battery tray. 
Wick

Avatar / Picture

Member
Registered:
Posts: 64
Reply with quote  #15 
Damn, this is serious John [wink]
Previous Topic | Next Topic
Print
Reply

Quick Navigation:

Easily create a Forum Website with Website Toolbox.