awsum140

Based on that, SMY seems to have a decent battery sled. I haven't used an HE2 in mine, yet. The HEs I have are pretty old with lots of cycles on them so I got some HD2s and HG2s. HDs for the current rating, HGs for the mah rating. I get over a tank, Aromamizer V1, out of an HG and about a tank out of the HDs. I'm running 40 watts but 75 watt preheat.

I am convinced that a good 18650 is more than suitable for the DNA75 IF the battery sled is good enough to support it. After a few batteries worth with the new sled, the batteries are consistently going on the charger at 3.2 volts or lower. Before this sled they were normally in the 3.5-3.6 volt range going on the charger. I'm getting a full tank, plus, using an Aromamizer compared to less than a half tank with the Keystone sled.

I haven't tried SS yet, Chunky. What grade/type are you using?

I think the biggest reason for premature "weak battery" warnings, with hand-built mods, is marginal contacts inside the battery holder. I rebuilt the holders in the DNA75s I built. I just got "weak battery" warning, changed the battery out and put it on a charger. The battery was showing 3.27 volts when it went into charge mode.

Significant titanium oxide will form at high temperatures, in excess of 800F. Vaping at that temperature would be, basically, impossible whether in temperature or wattage modes. Additionally, the one case of cancer "caused" by titanium oxide occurred in a person who worked in an atmosphere laden with TiO2 for years, about 20 if I remember correctly. One thing ignored in the reports of that incident, usually, is that the person was also a heavy cigarette smoker. I use titanium wire, exclusively, for coils and am completely confident is safe as I use it. Everyone is certainly free to draw their own conclusions and act accordingly. Do your own research. Reports from experts are always the best source of information.

I guess you'll be mounting the tube "upside down", screw cap on the top of the mod then.

Nice job, but let's see the insides, especially the battery and battery holder. I'm always looking for better ideas.

Yeah, then you need to worry about the quality of the connections as well. Maybe I'll look on Fleabay. Back in "ancient times" I used to have access to stuff like that and it was all traceable to NBS and sure didn't come from China.

Bill, when I build a mod I am a firm believer that "bigger is better". I always use the maximum wire sizes from the spec sheet, even though I rarely, if ever, go over 50 watts even with a DNA200. My theory being that minimizing loss, and lowering impedance at the same time, can't hurt anything and may help. We're dealing with very low resistances at firly high power/current and every little bit shaved can make a significant difference, at both the supply and output sides. Just my semi-educmacated, (im)practical experiences anyway. I just wish I had a meter that resolved down to .0001, or lower, ohms so I could see the fruits of my efforts.

Supposed, quality LiPO batteries, Samsung, Panasonic, LG, and some others, should have a life expectancy of about 500 charge cycles. How discharged that may be before charging is an open question. I have a small "stable" of LG HE2s and they're starting to die at 100 cycles, and I track every cycle for every battery I own. Letting them discharge to low levels, lower than 3.2 volts can shorten their life/charge cycles. Charging them when at higher levels, say 3.5 volts, supposedly increases their life/charge cycles. Overall, their is a finite amount of power, derived from a chemical reaction, so either way I would guess the total power output is about the same.

You'd be looking for poor/loose connections or maybe excessive rosin around those connections, balance connections. The balance connections are on the bottom of the board between the positive and negative battery connections. There could also be a bad connection between the contacts for the batteries and the input for the balance connections, bad solder joint for example. Needless to say, you'd want the batteries out of the mod if you go this far with it. It is entirely possible that a thin layer of film built up between the batteries and the contacts. Simply removing and re-installing them can easily remove that kind of film, which isn't visible to the eye. Normally, I'd expect the current flow to "erase" that kind of thing, but it may not. The balance monitor can be a little sensitive.

Start with basic maintenance. Pull the batteries, clean the contacts inside the mod and on the batteries themselves. If that doesn't help, time to check the wiring inside the mod for problems at the balance connector. If that doesn't work, time for an RMA.

Bill, you made me look. Granted these traces are from a DNA75 and a DNA200, but one, the DNA200, has the 510 connected to the board with a 12 gauge wire and the other, DNA75, get ground for the 510 from the body and gets board ground the same way. Both traces show fairly smooth temperature regulation, no sharp peaks and valleys.

Here's the latest iteration with an 1/8" brass positive contact and a 1/16" brass negative contact. The negative has a braided connection to the 14 gauge connection lead. I have one more improvement to make which is changing the spring from the stock one to a copper/beryllium, silver plated, spring. It still won't be a current path but after careful, scientific, testing (pressing down on the springs while on a small scale) I found the copper/beryllium/silver plated one needs three, plus, pounds versus just over two and a half for the stock spring. One of the good features is that there are no exposed solder points or wires. I've been using 14 gauge silicon wire to also minimize losses even though the lead lengths are under two inches. All connections are inside the sled, nothing exposed anywhere. The sled also fits snugly enough that it doesn't need to be wedged, or glued, into an ERM enclosure (at least the Proto/ERM enclosures). Looking at it in eScribe, the sag has been significantly reduced under preheat using this sled style which would seem to validate the improved conductivity of the contacts.

Thanks, Chunky. This is actually the second iteration of improvements to the sled, say version 1.0.2. I'm not using this one, it's for the "war department", but I did try it out and got the basic setting in I think she'll be using. The first one I modified, 1.0.1, only produces "weak battery" warnings when the battery is actually getting fairly weak, say 3.5 volts or so, and I think this one will be even better. Looking at it in eScribe the sag was drastically reduced compared to the one I'm using. Then again I'm running at higher powers with an Aromamizer and max air flow.

This is my second Proto Vape, ERM, DNA75. I used black buttons this time and have improved a battery sled for use in it. The positive contact is an 1/8" brass disk soldered to a 1/16" brass plate. The positive lead is soldered to the brass plate. The spring has 1/16" brass disk attached. A piece of braided, tinned, copper, shield is soldered to the disk and provides the negative power connection for the board. There are no exposed contact points anywhere on the sled. A pull ribbon makes battery changes very easy despite a tight battery holder.

I'm not a real fan of Hobby King, but they do offer some 1S LiPO packs at lower pries than that one, I think. Turnigy seems pretty decent. I have three of them in 3S powering DNA200s and they're holding up well, approaching 100 cycles on all three, and life/recharge time are still at great levels.

What brand/model are those batteries, Tiger? Something like this http://www.hobbyking.com/hobbyking/store/__18558__Turnigy_2200mAh_1S_20C_Lipoly_Single_Cell_.html can be stacked, if your soldering skills are good. Someone I know has five of them, stacked, in a beautiful, custom, ERM style enclosure an says it lasts for a weekend.

Again, I want to stress that my goal is firm, broad, low resistance, contact, not the strongest possible spring/contact. Too much spring strength makes it too hard to install and remove the battery. A wave spring would be nice but coils are more readily available.

He got back to me about current capacity. He apologized for not knowing, saying they are just "spring guys", got a print and made the springs. He did say they were originally made for use in "vaporizer pens" though. I suspect that it would be fairly high, on the order of 20 amps or higher but I am always circumspect with beryllium, it's a know carcinogenic. Granted, we're not going to vape the spring, but machining it can lead to spoils/particles/dust which isn't a good thing. I may buy some just for hahas though. In the mean time I'm working on another sled for another Proto/ERM/DNA75. This time the positive button will be a disk of 1/8" brass rather than 1/16". The extra space allows more clearance for the wire connecting at the bottom corner of the mounting plate and will also add just a little more pressure from the spring. I'll post some photos after the JB Weld hardens, probably Wednesday.

I already got a reply and they have 9.5 inch pounds. He didn't mention a current rating so I asked again.

I just asked what the compression force rating is and what the current rating is on those springs. Lets see what the reply is. By the way, we're not trying to build suspension for a car here, just hold a battery firmly enough to insure good connections (said with a smile and tongue in cheek). It is interesting to note that "modern" automotive suspension is either coil spring or torsion based.

I dunno. The spring only provides tension to hold the battery tightly against the positive contact. Both contacts are flat, providing maximum contact area with the battery terminals versus the small contact area of a piece of bent springy steel, which also has significantly lower conductivity than brass even if nickel plated. The spring does not conduct because the negative contact plate is connected by a piece of braided, tinned, copper shield. Overall a much lower resistance, higher conductance, solution than two small, springy, steel connections.

Technically, you don't need to turn TC off for kanthal or nichrome. The mod will see that the coil resistance does not change and will drop out of TC mode by itself. You could always create a profile for non-TC use and just switch profiles as needed if you'd like to have that option.

I was constantly getting "weak battery" with the Keystone sled. With this sled I finally got one when the battery was down to 3.48 volts, HD2. It is surprising what a decent contact between the battery and the holder can do. Somebody should start making a decent battery sled that is capable of handling the current that batteries can produce. Not to mention the loads a lot of gear, besides mods, can put on them. Somehow 24 gauge doesn't seem quite appropriate to me.