Worlds Smallest 510 Voltmeter

[Pipes]

Here's a quick mod for making a very small voltmeter for your 510 device. Takes the guess work out of battery condition. I'm sure we have all seen these types of meters.

Although I have been close to buying a couple times, I really thought there must be a smaller alternative. The smallest unit I could find was this one.

Available here.

Notice the size. It is only 14 mm wide which is the diameter of a 3.5 ml dual coil tank.
Hopefully with a little luck and maybe a little filing it should just slide on in.

Available here.

This unit has smoked plastic and has Delrin ends.

So combine this with the meter and a female 510 connector, add a little labor and you should have the smallest meter around. The result would look like the picture above that has a meter installed but in a 3.5ml package.
Here is a picture which is a better shot to show the size difference.

I have a meter on order and will update when received.

Cheers and happy modding,
Pipes

 

[placetime]

do you have a link for that first one?

 

[Pipes]

do you have a link for that first one?

Those were just example shots I found. Searched again and found this one here.
Can likely find cheaper. Google "510 volt meter" and view images only. That's the method I use to zero in on stuff.

Pipes

 

[hanfhead]

Nice man I was looking into these the other day because I've been pulling my TV apart to test the batteries with a multimeter constantly.


This one looked pretty cool.

And if only we could get one this small.

 

[Pipes]

Good find there. I know that since that meter was around it would not be long. Usually those type of devices start from suppliers in China and then saturate the market like those slightly larger ones did. The larger ones are like $2 each from China where as the newer smaller one is $6 each.
What did you pay for yours? If you don't mind me asking.

Pipes

 

[hanfhead]

That is not mine, just a picture I found. Last week I saw a guy in a vape review video with a huge inline meter built into a project box and went looking for something smaller. I found it here http://vapeporn.com/2012/04/510-to-510-extension-voltmeter/

 

[Pipes]

That is not mine, just a picture I found. Last week I saw a guy in a vape review video with a huge inline meter built into a project box and went looking for something smaller. I found it here http://vapeporn.com/2012/04/510-to-510-extension-voltmeter/

Aye, it's actually a mod from another forum site. Must have found the same meter.
Cool, bet it will be at MadVapes in no time.
That other meter you showed inside the handle is an LCD back lite type. It was actually what I was hoping to find as a stand alone device but could not find. Display yes, but not pre-configured as a voltmeter. I agree it would be nice.

Pipes

 

[hanfhead]

I found those same size meters on ebay for around 3 bucks shipped. I grabbed one with blue leds to play around with. I am curious to see how it fits in there. Do you know how long that tank is? Maybe we can shorten the tube some too. Well I think my meter is coming from China so I have some time to order a tank and find some 510 ends. What are your thoughts on securing the top female fitting to the cap on the tank? Press fit into the delrin? I wouldn't want to use anything like epoxy right there as the airpath on an evo is near there. Maybe I can find a threaded 510 connector.

 

[Pipes]

I found those same size meters on ebay for around 3 bucks shipped. I grabbed one with blue leds to play around with. I am curious to see how it fits in there. Do you know how long that tank is? Maybe we can shorten the tube some too. Well I think my meter is coming from China so I have some time to order a tank and find some 510 ends. What are your thoughts on securing the top female fitting to the cap on the tank? Press fit into the delrin? I wouldn't want to use anything like epoxy right there as the airpath on an evo is near there. Maybe I can find a threaded 510 connector.

Good find on the meter on Ebay. Are you sure of the size? There are a lot of the larger one around. For mounting the connectors, I was thinking of using a normal tube (maybe the one that is a carto and comes with the tube.) Cut 2 lengths to maybe 1/2 inch long, pressure fit the connectors. Not sure about what will be needed to secure the connector short tubes in place. Ideally if the tube is wide enough it might be possible to notch a strip out of it leaving some tube in place along the rear of the meter. If not then yes epoxy seems the way. Once epoxy is hardened I really don't thing air-path for the devices would be a problem. If anyone knows any reason to NOT use in this application let us know.
The connectors are available from this page. There are silver a gold types. I get the cheapest gold ones and for male 510s I get the tube as it comes with a connector as well.
The method I have been using to remove connectors from tube is to find something to slide inside the tube to use as a lever and screw the connector into a good handle. Wiggle the lever back and forth until you see the tube start to separate. Once started it can be pulled straight off. Always been carefully not to loosen the connector on the power handle as it too is just pressure fit in.
Pipes

 

[hanfhead]

Here is the meter, got it today. It really is tiny, much smaller than a cr123. It says 3.3-30 volts. Now to wait on the rest of the parts.

You have really got me into the modding mood, I have a few other ideas now. I used to build and mod flashlights but am new to modding ecig stuff. Although I have built 3 decent diy vapes.

 

[Pipes]

Good stuff. I'm still waiting for my meter. Starting to wonder if can fit into the 3.5 ml tube. I received the pieces your waiting for. (tube and connectors) The ID of tube is 13.5 mm (measured with calipers). So helpfully with some filing it can cram in there. Going to need to file about .25-.3 mil off the sides. In close examination of the pic posted from other site, it's tube is slightly larger then a standard 3.5 ml one. Wondering if the maker hit the size problem as well.
Anyway, we'll figure something out.
Pipes

 

[Pipes]

Well, crap. First off it was a bit too big. The one in the pic Hanfhead posted above is still eluding me.
Anyway, I did manage to get it together (kind of) and would have lived with it with the front of meter exposed.

But while testing it I used my TV handle. Problem is I put my batteries in upside down.
Found out quickly that this meter has no reverse current protection.
The meter fried.....uggg
Oh well, win some lose some. Still keeping an eye out for that small one from above.
Note it has 2 digits instead of 3.

Cheers,
Pipes

 

[hanfhead]

Yea, I nicked a trace for the center row on the leds but I got it small enough to fit in the tube only slightly skewing it. I spent a little bit of time trying to repair the bad trace with a strand of copper wire but as soon as I slide it in the tube it pulls back off.

As for the one in the pic I posted, I know where it is from now. I found a site in Romanian where the guy made them. He doesn't give any details and won't sell them from what I've gathered.

Here are the links if you want to mess around.

http://vapersforum.ro/baterii/mini-voltmetru-home-made-digiti-t2060.html

http://vapersforum.ro/baterii/mini-voltmetru-pentru-moddind-t2026.html

 

[Pipes]

Well I had to finish what I started. Got another meter to give another shot. This time installed reverse polarity to match the way I use the TV handle with the batteries upside down. I guestimated that I too would nick a trace if attempting to take down enough to fit the tube. So I just went the route I tried the first time.
Finished it with filling with epoxy so it's solid as crap.

Don't mind the cat, she's just wondering WTF?

Finally, I now know when to change batteries for the DART. This was one of the main reasons I really wanted this. The low battery and DART/REV unit has always been a hard one to nail down.

Hanfhead. never did find that 2 digit job. Can't find in those links anything about where to get it. As the guy who made it stated, the delay for the display in the unit we used has an annoying 1-2 second delay to show the voltage. Apparently this is instant with the 2 digit unit.

If rating this mod I would have to pretty much fail it as there is hardly any cost savings from pre-made units and the display will not fit as hoped into the tube which is easily available for most in their ecig supplies.

Anyone know if the reverse polarity thing is a no no with all these little meters? Do they all blow up if reversed? A definite downfall for those who have devices which batteries can go in either way as I found out. I would use a small bridge rectifier if I could re-calibrate the meter for the .7 volt difference. (diode drop) This would make it not care about polarity. Would lose the bottom end of measurability by the .7 volt difference but for this application it would still be OK.

Pipes