The "WeekEnder"

[mikepetro]

Good to know looking forward to your results, 'cus I might be copying you.

I had plenty of room in my mod since the Lipo was a lot shorter than the old Bat Holder, but soldering the bullets directly to the 510 connector took up a lot of space. In tighter quarters it wouldnt work so good.

If you choose to go this route you might want to solder a short length of wire (a pigtail) to your positive pin and retainer nut, then solder the bullets to the wire pigtails. Then you could then tuck the bullet in some little cranny somewhere.

On the 510 I just used the bullets, on the Lipo I used the bullets with the blue shell.

For size comparison, this is an 18500:

 

[mikepetro]

mike, I spy a kelvin meter. Just curious if you got that for working on vaping gear or if you need precision for another hobby or job?

Hehehe, sharp eye. I got it mainly for testing vape gear , but I needed a new meter for home anyway and this also functions as a multimeter.

 

[DrMA]

Nice testing, mike.

 

[bapgood]

I did some testing this morning as well.

I tested the spring pin and got 10mΩ.

 

[bapgood]

So to go along with some of the resistance testing.....see below for what I noticed on my SxS mod.

I have been doing some resistance measuring and etc. and I was planning on using an Origin mech ss battery tube for the inner battery tube, but I picked up some Copper 122-H04 Hard Drawn tubing and made the inner battery tube and switch housing out of it. Wanted to use 101 copper but its $$$ and the 122 hard drawn actually turned/threaded and worked pretty dang good. The switch housing is copper with a ss ring threaded and soldered on, I used a silver plated contact from a chi you clone and soldered a wire from the silver contact to the copper housing.

Right now I'm running fuse-less because I didn't have any 6amp fuses, but I know I have shed a decent amount of resistance since my 1.5 ohm atty wouldn't fire below 9.1 watts (~3.9v) until the battery had drained some. I have several other DNA mods and they all fire the same atty on fresh battery(s) down to at least 8.5 watts, haven't checked lower as I have typically been running it at 8.7 watts. So it will be interesting to see how much difference adding fuses makes.

I have the parts to mock up a version with ss battery tube and switch housing, so I can measure both and compare.

 

[BJ43]

I did some supermarket testing yesterday. Zero resistance....

 

[bapgood]

Wow!!! Check out the fuse I just found!!! 7amp 0.001-0.007Ω 2920L700SLPR

 

[mikepetro]

Wow!!! Check out the fuse I just found!!! 7amp 0.001-0.007Ω 2920L700SLPR

Yep, that is about the only surface mount one in the 5.5-7.5amp range that doesnt require an MOQ of a 1000+ piece reel. Still kind of pricey though.

I bought a handful of these a few weeks ago, until I find something better.
16R600GU - LITTELFUSE 16R600GU - FUSE, PTC RESET, 16V, 6A, RADIAL | Newark element14 US

 

[bapgood]

Yeah they are a little pricy, but 2 is going to cost less than your lunch today

 

[mikepetro]

Yeah they are a little pricy, but 2 is going to cost less than your lunch today

I wish that were true, didnt get a chance to go to lunch today, busy day at work!

 

[mikepetro]

Yeah they are a little pricy, but 2 is going to cost less than your lunch today

I really do like the SMD though. I have some prototype PCBs I am playing with, they work nice on them.

 

[turbocad6]

hey guys, stupid question I guess but you guys are always playing with those rc batteries so I'm hoping maybe one of you may know of something that will fit a mod I'm building into an old cellphone body. figured something like that would be good for the most stealthy situations.

what i'm looking for is something that is somewhat close to an 18650 but I'd rather not have the full 18mm depth. ideally I'd like something that is maybe up to 30mm wide but only ~14mm thick, length can be a bit more than an 18650, anyone know of anything close to this or am I just dreaming and I should just stick the 18650 in there and build around that. any input would be appreciated.

 

[bapgood]

hey guys, stupid question I guess but you guys are always playing with those rc batteries so I'm hoping maybe one of you may know of something that will fit a mod I'm building into an old cellphone body. figured something like that would be good for the most stealthy situations.

what i'm looking for is something that is somewhat close to an 18650 but I'd rather not have the full 18mm depth. ideally I'd like something that is maybe up to 30mm wide but only ~14mm thick, length can be a bit more than an 18650, anyone know of anything close to this or am I just dreaming and I should just stick the 18650 in there and build around that. any input would be appreciated.

That is a tough size, any lipo that size will likely be less mah than a good 18650. You can check out Hobby King but I bet most flat cells will be wider than 30mm, I will try to remember to measure some when I get home. Hobby King has some 800/900/1000/1200mah round lipos that would probably work but then your getting somewhat small mah. What about a 14650 or a couple of 14650's?

 

[mikepetro]

hey guys, stupid question I guess but you guys are always playing with those rc batteries so I'm hoping maybe one of you may know of something that will fit a mod I'm building into an old cellphone body. figured something like that would be good for the most stealthy situations.

what i'm looking for is something that is somewhat close to an 18650 but I'd rather not have the full 18mm depth. ideally I'd like something that is maybe up to 30mm wide but only ~14mm thick, length can be a bit more than an 18650, anyone know of anything close to this or am I just dreaming and I should just stick the 18650 in there and build around that. any input would be appreciated.

I suspect that to get that size you are going to have to sacrifice some capacity.

These are 34mm wide, 2 of them would only be 12mm thick, it would give you 2000mAh.
Turnigy 1000mAh 1S 20C Lipoly (Single Cell)

These are 31 mm wide, but two would only give you 1700mAh.
ZIPPY 850mAh 20C single cell

Look around at some of their other single cells.

 

[DrMA]

Yeah, the 850mAh cells are ~31mm wide. I use them in my 9V box mods.

 

[mikepetro]

With all the talk about battery, fuse, and connector resistances I thought I would take a look at some attys. My reasoning being that if the connections in the atty are high resistance then some of that wattage you are pumping out of the DNA/Vamo or whatever is actually being wasted. Sure a VW mod will put out what wattage you tell it to, but if part of the resistance it is seeing cannot be converted to heat in the coil then that would be an inefficiency. The resistance of the atty connections also have a voltage drop associated with them.

• All resistance measurements are in mΩ and measured using a Kelvin style multimeter designed for measuring very low resistance.
• Used a Fatdaddyvapes 510 connector for all tests
• All measurements were adjusted to zero out (ie tare) the resistance of the Meter leads and the 510 connector. (10.3 mΩ total)

Atty	Positive Leg	Negative Leg	Total Resistance	~vDrop
TGT Clone	21.6	4.1	25.7	.07
Rocket	3.8	2.4	6.2	.02
R91	9.5	5.6	15.1	.04
GKMF22	14.2	2.9	17.1	.05
AGA-T2	17.6	48.7	66.3	.18
UD AGI Stock	497	3.7	500.7	1.35
UD AGI Modded (removed spring)	8.7	3.7	12.4	.03
Pulse G Clone	6.5	3.2	9.7	.03
DID Clone	19.4	4.8	24.2	.07
Aqua Clone	12.9	11.1	24	.06

The results were surprising in a few spots:

• Turns out one of the cheapest device (The Rocket) was actually the most efficient. The Pulse G clone did pretty good as well.
• The good ole AGAT2 that I broke my RBA teeth in on was not very efficient at all.
• The R91 was extremely unstable to measure. Resistance went very high easily. I suspect it is the spring in it. I cant help but wonder if the resistance changes under normal use as well.
• The UD AGI Stock (never used) was absolutely horrible. It went off the mΩ scale, had to use the Ω scale. The measurement was repeatable across several tests. I feel certain it is the spring that makes up part of the positive post. I had another AGI where I removed the spring and replaced it with a length of brass tubing it fared MUCH better.

 

[MikeE3]

Nice work. I often wondered how much i lost with that big spring in the Z-Atty's i so rarely use.

But - You got too much time on your hands. Better setup a visit w/ your girl friend.

 

[mikepetro]

Nice work. I often wondered how much i lost with that big spring in the Z-Atty's i so rarely use.

But - You got too much time on your hands. Better setup a visit w/ your girl friend.

Mmmmm she left around lunchtime. Hence I wasnt online much yesterday......

 

[Schnarph]

Nice work Mike, appreciated. I would imagine an RSST with silver plated center post would have done extremely well. It's a good thing the TGT has a brass plate on the inside, it would have been a hefty vdrop if that was SS.

 

[BJ43]

[*]Turns out one of the cheapest device (The Rocket) was actually the most efficient. The Pulse G clone did pretty good as well.

Love my half dozen rockets, great test platforms and for some reason always seem to perform better than the higher priced...

BTW interesting test. Thanks. On more gennies you would probably get the same and many cheap will have less resistance.