Hello! Back in April I ordered a Rebel dual 18650 squonk mod from eSauce. It arrived in May and I was ecstatic! This was my first venture into the worlds of both squonking and DNA chips, and I couldn't wait! I opened it, threw in a brand new pair of freshly charged Samsung 25Rs, filled the squonk bottle with my favorite juice, threw my Dead Rabbit RDA on, and nothing. It wasn't firing at all. After a bit of searching, I connected it to EScribe and found the chip to be programmed for a 4s LiPo battery vice dual 18650 batteries. This was super confusing, especially considering that "Each unit is hand finished and tested using extensive quality control techniques." I guess putting batteries in and a mod on top, then pressing the fire button doesn't fall into these "extensive quality control techniques."
Anyway, I changed that and all was good, or so I thought. My battery life has always seemed extremely short to me. I finally sought assistance from the Electronic_Cigarette subreddit (https://www.reddit.com/r/electronic_cigarette/comments/abc1a8/dna_250c_weak_batterymassive_drain_on_dual_18650s/) and was reminded of this forum, along with getting some solid advice from u/Wayne0.
I don't vape indoors, so I threw a build in an RDA that I wasn't using and dry fired it at the same settings I usually use while monitoring in Device Monitor. I have to admit, I was pretty surprised when I saw that I was consistently getting a 0.8 V sag, no matter the batteries I was using. I tried four different mated pairs, all while firing a 0.116 Ohm build at 90 W. At that resistance, there should be nowhere near that level of sagging. I cleaned all battery contacts and battery ends with isopropyl alcohol with absolutely no change. I cleaned the 510, as well. Still nothing. One screenshot from Device Monitor is attached, but I'm happy to provide more if interested.
Great, not I get to take it apart and find the bad solder joints. After I got the board out, there was a weird rubber(?) coating covering all of the soldered connections. I can only guess this is to help with shorts, but it seemed excessive to me. Admittedly, I was (and still am) probably still just irritated at the whole situation and overreacting. Either way, once I got the coating off, I was pretty surprised by the solder job. I used my ceramic tweezers and very carefully removed the coating to ensure I didn't damage the board or the contacts at all, so what you see in the pictures is exactly how it left eSauce, sans a little rubber.
While I can see what they were trying to do with the battery connections, it looks like they just pooled a bunch of solder around a few extra strands of wires to connect the sensing points. I get it, but it looks sloppy and lazy. This may be fine, and the resistance between the battery contacts and the back side of each corresponding contact on the board is 0.2 Ohm, so I guess it's functional. The biggest thing that caught my attention was where they soldered the 510 wires. Not only do the solder points look dry, but it looks like they burned the board. There is room in the mod for them to have soldered the wires going up, away from the board, instead of down and over the board, soldering at a weird and awkward downward angle to avoid interference.
Now that the back story and rant is done, I think it's about time to begin desoldering, cleaning, and soldering in new wires in an attempt to fix my initial problem of having a 0.8 V sag when firing. I'll update with more pictures and results as I go.
If you have any recommendations, complaints, or criticisms, I'm more than open to them. If I'm being stupid about any or all of this, also let me know. If you've had a similar experience, please feel free to vent. Looking around a little bit, mine is far from an isolated incident, but I didn't see any specific examples, just people alluding to others' experience with poor quality control with Rebel mods. I did consider sending it back to eSauce, but being in the US, I really don't feel like waiting for shipping to and from the UK.