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250C 2 cell wiring question


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Hey everyone! All of my parts for my custom build came in today, and it will be the first mod I've built! I have a wiring question though.


Here is the wiring diagram from the DNA250C manual:



I noticed that there are two wire going form battery negative to B- and "G".  Additionally, the positive going to the B+ has a second wire going from positive to 2, 3, and 4. So instead of running a second wire from Positive and Negative of the batteries, Can I just bridge B- and B+ to "G" and "2, 3, 4" respectively? Here's a diagram showing what I mean:


Would the above allow the mod to draw from the batteries and do the balanced charging? And allow me to vape while charging? Or do I need to run the second wires? I've been looking at pictures of people's non-LiPo builds, and none of them show how they wire up the balanced charging due to the picture angle, but none appear to have a second set of wires from battery positive and negative to the balanced charging, so I'm assuming they are wired up bridged from B- and B+ like in my second photo. That or people don't connect the charging. Anyway, I'd love some clarity on this before I do my build this weekend!

Thank everyone!



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Good morning @retird! I feel like I may not have been clear. I know G, T1, T2, T3, and T4 control the balanced charging, and I know that the DNA boards support Vape while Charging (the charging circuit actually shuts off when you press the fire button so it isn't actually firing while charging, but it does allow you to use the device while it is plugged into USB for charging). 

What I'm looking to find out is whether or not I have to run the small charging wires parallel to Battery Sled Positive and Battery Sled Negative, or whether I can bridge the connections at the board. 

Below is a picture of a DNA250C build by David4500 (he's a big contributor to reddit.com/r/OpenPV). It certainly looks like he has gone with the bridging method in the picture (the second wiring diagram I linked in my post), and there are no secondary charging wires run from Battery Sled Positive and Battery Sled Negative (the top of the sled in the picture). He only ran the wire from the bottom of the battery sled (where Battery1 negative is connected to Battery2 positive) to T1 on the charging circuit. G on the charging circuit looks to be bridged off of B- on the chip, and T2, T3, and T4 appear to be bridged off of B+ on the board.

I'm looking for confirmation on whether or not wiring as shown in my second wiring diagram (and appears to be shown on the build in the picture below) will work properly. In the end, what the "shortcut" method does is use the same wire for drawing in battery power as it does for sending power out to the batteries. Since the charging circuit shuts off when you fire the mod while it is plugged in, this "should" work fine in theory since the single wires to the battery sled positive and negative would never be drawing current (firing the mod) and sending current (charging the batteries) at the same time. The only risk I see in using the shortcut is that power is delivered to the charging circuit when you fire... But electricity takes the path of least resistance, so there should be no excess power delivered to the charging circuit. That said... I didn't engineer the board, and while I'm very familiar with board level IT work since I do it, I don't know if there is anything funky in this chip that would make this "shortcut" wiring not work properly. 

So in short, I know exactly what all of the pins on the board do. I know Evolv made this chip to support up to 4 cells, and that the charging circuit connections are laid out the way they are it to make is very easy to plug it into a LiPo battery by soldering a JST XH or JST PH connector directly onto G, T1, T2, T3, T4. For people using a battery sled though, the "shortcut" wiring method of bridging B- to G and B+ to T2, T3, and T4 "should" work. I'm just looking for clarity from someone who has done it saying "yes you can do that, I do that" or someone knows more about the way the charging circuit works to tell me something like, "No, this will send excessive voltage into T2, T3, and T4 which will burnt out your charging circuitry". 



Edited by DkPatriots
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  • 8 months later...
35 minutes ago, anthony said:

Did you get a proper answer from evolve about that wiring?

I did! You can wire it using the shortcut, but it will result it voltage drop across the board, which means the board will believe your batteries are slightly more "dead" than they really are. This is minor, but it is there so it is recommended to run the extra wires. You can use the shortcut though, and it is safe to do so. I ended up running the extra wires.

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