awsum140

I finally got the new sled into the ERM-DNA75 this morning and it makes a BIG difference. I'm using LG HD2 batteries and at 1/2 charge showing on the battery meter I only get a "weak battery" warning once in a while. The Keystone sled was giving them after five hits on a fresh battery. I did some modifications to the sled. The positive terminal is a laminated piece of brass with the brass center disk soldered in place. I also found a "deep well" socket that was a little bigger in diameter than an 18650. I put that into the sled and heated the whole thing with a heat gun. Now the battery fits normally and comes out with no difficulty while still being held firmly. The sled is almost a force fit into the Proto ERM enclosure so no wedging to get a tight fit. Overall, well worth the added effort.

The ticket system, apparently, is automated and if no input is made on a specific ticket, no matter what the reason, it gets closed. That happened to me as well but it was my own fault.

So, I bought some different battery sleds with the idea of modifying them They came with 24 gauge wire on them. What are manufacturers thinking? I drilled out the rivets from both ends to get everything out. I replaced the positive contact with a 3/8" brass disk with 14 gauge silicon wired soldered directly to it. I added a 3/8 brass disk to the negative spring and soldered a short piece of braid, from a piece of RG6, to it and soldered the disk to the spring. The shield was trimmed to length and soldered to another piece of 14 gauge silicon wire. The spring can conduct, of course, but the rel path is the braid. Everything was placed back in using JB Weld. I also added a pull ribbon to get the battery out because the sled has a death grip on the battery. I've still got to find the time to swap out the Keystone sled with this one and build at least two more like this..

The "weak battery" can easily be a result of voltage sag caused by the high current demand of the preheat. Looking at eScribe as I fire my DNA75 with an 18650 shows the voltage drop during preheat is really quite high and not an indication of a problem with the chip or the battery, just a result of a very high load. Even a 26650 will sag, significantly, under loads like that which, in turn, trigger the "low battery" warning. The chip just sees the voltage drop to the "low" threshold and triggers the warning.

I'm actually designing around the available enclosure I found, FleaBay item. I want a low tank, or side by side, form factor. The end result is needing some way of holding the battery in position and supplying a way to change the battery conveniently. Cutting a round hole for a battery is no problem, but with limited tooling and skills, cutting and threading a cap is a whole other problem. The tube solves all three problems and there is more than enough room inside the case. Size is not my biggest design factor, the low tank is the governing factor and I'll sacrifice a little bigger enclosure to get to that goal.

VB, you don't think that tube would work for a 75 watt, max, mod? The contacts look very substantial to me, especially compared to a typical battery sled. The fact that the bottom provides pressure when screwed in almost guarantees a good connection every time. As far as size, there is space inside what I am building due to the diameter of RTAs like an Aromamizer. A few extra mils in overall width aren't really all that important to me and is being dictated by the extrusion I'm using.

Fat Daddy has battery tubes in brass or stainless for both 18650 and 26650. Fixed positive post and the bottom post is actually the bottom cap and be screwed in to make a nice, tight, connection. Scroll bout a third of the way down the page - http://fatdaddyvapes.com/shop.html

I'm working, sort of, on some low tank DNA75 mods and have FD battery tubes for them. Those are nice and secure but way too big to fit into an ERM.

I was hoping for something commercially available. It's amazing that 18650s can put out 20 to 30 amps and the holders offered don't look safe at 10 amps. I did look around and ordered a few with springs for the negative terminals. My plan being to use a brass plate and braided cable on the negative, spring, end and a brass button style on the positive end. Both will be 14 or 16 gauge wire depending on what will actually work.

OK, I'll kick off this category. The DNA75, by virtue of being a 3.7 volt chip, is a good candidate for a single 18650, high drain, battery. I recently built a DNA75 into an ERM enclosure and it does make a nice, compact, mod. The problem is the battery sled. I'm using a Keystone 1044, single, 18650 sled and the are a couple of weak points with it. The contacts are, at best, marginal given the current draw of the DNA75 even at "lower" power, like 30 or 40 watts. They are kind of flimsy and I've already had to re-bend them, twice, to maintain good contact. I've thought about modifying the sled with more substantial contacts but find a suitable spring gets to be a problem as well. The next problem is mounting it so that it is semi-permanent. The sled does need a little "massage", on one end, with some sandpaper or a file to fit into the enclosure. The enclosure I have, from Proto Vapor, has a nice little ledge inside the front half of the enclosure that keeps the sled from pressing on the board, but keeping it in there tight enough to allow easy battery changes is a challenge. I've got it "wedged" in place, which works, but I'm leaning toward hot melt glue to keep it a lot more solid. Given the "tightness" of the sled, and the sled inside the enclosure, screws just don't seem to be an option to me. Any suggestions out there?

And maximize weight and size.

Nice work, VB! I like the battery holder, excellent solution.

The sag is substantial, say down to 2.5 volts or so, but it's only for the "punch". I'm vaping at 40 watts and it sags about .2 to .3 volts under that load. If you find a decent sled that will fit into an ERM, let me know what and where. This Keystone, while it works, is kind of pathetic for this kind of application.

I finally got around to putting this together this morning. It's a Proto ERM enclosure that I modified with magnets to hold the back on. The battery sled is a Keystone and I'm not very happy with it and will be making something more "custom" in the near future. I do love the DNA75, more than enough power for me.

The DNA75 runs on a 3.7 supply voltage, 1s.

You just convinced me to drop the 18650 idea and try my hand at soldering LiPOs to make a pack, Mike.

What kind/brand of mod are we talking about here? Things to check, besides what's already been mentioned regarding the screen ribbon cable. Check the 510 connector on the mod, could be a problem there. Check the wiring from the board to the 510. If you can post a screen capture of eScribe while attempting to fire the device, that might help as well.

My "secret" for soldering to a DNA, or other boards for that matter, is a temperature controlled station, lots of heat, quality solder and a tip that looks a bit bigger than is really needed. Tinning everything beforehand helps a bit as well.

By "the 4 charge wires" I'm assuming you mean the JST-XH balance connector connections. Assuming you re using that connector that should be soldered first just to limit soldering while power is applied. The "2 discharge wires" are actually the battery power supply to the board. It is probably safer to solder the positive lead first, then the negative lead. If you're soldering all the leads directly to the board it is probably still a good idea to start with the balance connector leads. Again start with the positive lead and work down to the ground lead. Above all use extreme caution when soldering the heavy battery leads to the board. Strip and solder one, then strip and solder the second and so on. In fact it's probably a good idea to put some tape on the lead(s) not being soldered to make sure the possibility of a short is minimized. Expect a spark when the second heavy lead is soldered as the board powers up. You do need good soldering skills and techniques. The board density makes soldering a little more difficult and working with "live" leads adds to that difficulty. Proceed at your own risk.

Sounds like my idea for an Express Wagon with dual car batteries, five gallon bucket of liquid and an aquarium pump to supply the atty. Seriously, I think you are way too light on the wire gauge. I use 12 gauge INSIDE my mods to minimize resistance and at six feet I'd be looking at eight gauge or heavier. That's what makes remoting the board from the atty a little impractical. Heavy enough wire is too physically stiff and heavy, even high quality silicon wire. Then you have to consider the added weight, and stiffness of something to encapsulate all the wires so you don't end up getting tangled up. Don't forget the added resistance of the XLR connector as well when figuring out the total for remoting like that. I'm not saying it can't or won't work, just that accuracy of TC will probably take a major hit.

The best way to figure out what will fit is to measure how much space you have inside the enclosure then go have a look at Hobby King under 3S LiPO batteries and check the sizes against what you have available. Keep in mind a little clearance to allow for expansion is a good idea. (LiPO batteries do expand a little) Also, make sure whatever you decide on is rated at a 30 amp continuous discharge rate.

Changing the battery would require de-soldering it and re-soldering the new one to the board. To remove the old battery you'd cut one lead at a time with cutters then remove the remaining wire from the board. After that, simply solder in the new battery. You do need to work with one lead at a time and keep the other lead insulated to prevent shorts. As far as size, mah, that will be determined by the available space in millimeters and what you can find commercially. I stuffed a 1000mah Turnigy Nanotech into a Hammond 1590G box, but there is no guarantee it'll fit in yours.

That board appears to be mounted in some kind of sled and the mod looks like it's based off a 159x enclosure. The battery was soldered directly to save space that a connector, and some extra wire, would need.

I'll assume you checked the obvious like something inside the 510 connector. Short of taking it apart and doing a careful physical inspection of the wiring at the output connections there isn't anything else to do. Taking it apart might void the warranty so I'd just send it back. Out of curiosity what charge level is on the battery? Sometimes one of mine will show "check atomizer" just before it says "weak battery".

The charger for the 3S LiPO is onboard the DNA200 which simplifies using a 3S.