Battery Help Please

[GoochMan]

I am using a mechanical Mod with sub ohm coils.
I don't have an ohm meter but I am running dual coils each with 6 wraps around a 3/55" screwdriver. 28 guage kanthal wire

What is the best battery?
I am thinking of getting an 18650 VCT 5, which is a 2600 mah.

I remember reading something a while back that if you are sub ohm you shouldn't go above 2000 mah but I am not sure.

Any help is appreciated and if anyone knows where I can get inexpensive batteries because I don't trust any of these local vape shops.

One place just tried selling me one of the VCT 5 batteries for $19 and a charger for $23. It seemed a bit overpriced.

 

[Big Me]

First, don't attempt to build anything without the ability to check the Ohms. Get yourself an meter ASAP. You have no way of knowing the correct resistance of the coil or if there is a short in the build.

Second, genuine VTC5s are very hard to come by nowadays. Most people atm go with either Purple Efests IMR 35A Pulse (20A Continuous) 2500mAh or the Samsung INR 2500mAh 25Rs

I can't help with suppliers as I'm in the UK but I'm sure someone else will guide you.

Also, brush up on ohms law and read Baditude's blogs on battery safety. (You can find them on this forum)

ETA - http://www.e-cigarette-forum.com/forum/blogs/baditude/

 

[2naphish]

inexpensive batteries are NOT the way to go. a good deal on a quality battery would be a much better choice. i feel pretty good going down to .35 with these 18650 Samsung INR18650-25R 2500mAh High Discharge Flat Top . as others have posted. there are things you have to know and things you must have ( ohm tester, volt meter) before using a coil you have built and before you risk your face with that build.

 

[ian-field]

I am using a mechanical Mod with sub ohm coils.
I don't have an ohm meter but I am running dual coils each with 6 wraps around a 3/55" screwdriver. 28 guage kanthal wire

What is the best battery?
I am thinking of getting an 18650 VCT 5, which is a 2600 mah.

I remember reading something a while back that if you are sub ohm you shouldn't go above 2000 mah but I am not sure.

Any help is appreciated and if anyone knows where I can get inexpensive batteries because I don't trust any of these local vape shops.

One place just tried selling me one of the VCT 5 batteries for $19 and a charger for $23. It seemed a bit overpriced.

At least one person has reported here that the DMM they bought doesn't have the resolution to read sub-Ohm values.

Some capacitor ESR meters can measure basic resistance as well as the loss resistance in a capacitor, in fact the one I built from a kit had to be calibrated with a selection of low value resistors - but check this before buying, ESR meters aren't cheap.

The most common hobby magazine approach to measuring low resistance is to pass a constant current through it and measure the volt-drop.

You could probably get away with an off the shelf power LED driver, but you'd have to include a couple of series connected silicon diodes to drop some of the output voltage and not look quite so much like a short circuit - you'd also have to measure what current it actually delivers so you can calculate the resistance from the volt drop.

 

[Big Me]

At least one person has reported here that the DMM they bought doesn't have the resolution to read sub-Ohm values.

Some capacitor ESR meters can measure basic resistance as well as the loss resistance in a capacitor, in fact the one I built from a kit had to be calibrated with a selection of low value resistors - but check this before buying, ESR meters aren't cheap.

The most common hobby magazine approach to measuring low resistance is to pass a constant current through it and measure the volt-drop.

You could probably get away with an off the shelf power LED driver, but you'd have to include a couple of series connected silicon diodes to drop some of the output voltage and not look quite so much like a short circuit - you'd also have to measure what current it actually delivers so you can calculate the resistance from the volt drop.

Huh? Wow! Any chance of translating this into simpler English so us non-techies can understand it, please?

It looks like something I'd like to know but it's going over my head at the moment.

Thanks!

 

[wshanncap]

#1 Get an ohm meter before ramping up another coil. Sorry to sound harsh but it is for your own safety. #2 I use Efest Batteries from 101Vape. I use red 10 amp and purple 35 amp depending on my needs. You don't know your needs until you get a meter.

 

[Roscoe01]

http://www.rtdvapor.com/new-aw-imr-18650-3-7v-2200mah/

Good battery...good price....great seller

And be sure to grab one of these....

http://www.rtdvapor.com/cartomizer-and-atomizer-ohm-meter/

 

[ian-field]

Huh? Wow! Any chance of translating this into simpler English so us non-techies can understand it, please?

It looks like something I'd like to know but it's going over my head at the moment.

Thanks!

Go to the allabout circuits forum - they have a series of tutorial books associated that take you from basic electricity to basic electronics, there's plenty of people on the forum can help if you have questions.

You need to know this stuff if you're going to mess with lithium batteries - they can burn your house down if you subject them to abuse!

 

[Ryedan]

I am using a mechanical Mod with sub ohm coils.
I don't have an ohm meter but I am running dual coils each with 6 wraps around a 3/55" screwdriver. 28 guage kanthal wire

You definitely need something to measure your builds for resistance or you don't know what it is and will not know how much current you're drawing from the battery. The lower the resistance, the higher the amp draw. Here's an online Ohm's law calculator you can use to figure out amp draw. Enter 4.2 volts and the resistance and hit enter. You should not draw more amps than the battery is rated for in continuous use, or it can get dangerous.

You will also need to be able to check for shorts.

I suggest you get an inexpensive DMM. It will also allow you to check battery voltage so you don't run them down too far and check volts off your charger so you know the charger is doing it right. If you're off with either of these the batteries will not last long and it can also get dangerous.

What is the best battery?
I am thinking of getting an 18650 VCT 5, which is a 2600 mah.

AFAIK, you can't get any VTC5's right now, everything on sale anywhere is counterfeit. The suggestion of a Samsung 18650 25R, 20 amp, 2500 mAh is a very good one. Illumination Supply has them for $6 a pop and that's the best deal I know of.

I remember reading something a while back that if you are sub ohm you shouldn't go above 2000 mah but I am not sure.

That's wrong

One place just tried selling me one of the VCT 5 batteries for $19 and a charger for $23. It seemed a bit overpriced.

You know about the VTC5 now. If you're looking for a inexpensive charger a lot of people are doing well with Nitecore Intellichargers like this. I think they are selling for under $20. Do not buy a $10 charger. They can be so bad they are dangerous.

With mechanical mods there are no safety features built in. It's all up to you to do things safely. Here's a great list of links to a lot of information about this stuff: One Stop Reference Shop For New and Experienced Vapers.

Please read about Ohm's law and how to use it for vaping. Baditude's battery information is really good and important to know. The more you know the safer you will be

 

[ian-field]

You definitely need something to measure your builds for resistance or you don't know what it is and will not know how much current you're drawing from the battery. The lower the resistance, the higher the amp draw. Here's an online Ohm's law calculator you can use to figure out amp draw. Enter 4.2 volts and the resistance and hit enter. You should not draw more amps than the battery is rated for in continuous use, or it can get dangerous.

You will also need to be able to check for shorts.

I suggest you get an inexpensive DMM. It will also allow you to check battery voltage so you don't run them down too far and check volts off your charger so you know the charger is doing it right. If you're off with either of these the batteries will not last long and it can also get dangerous.



AFAIK, you can't get any VTC5's right now, everything on sale anywhere is counterfeit. The suggestion of a Samsung 18650 25R, 20 amp, 2500 mAh is a very good one. Illumination Supply has them for $6 a pop and that's the best deal I know of.



That's wrong



You know about the VTC5 now. If you're looking for a inexpensive charger a lot of people are doing well with Nitecore Intellichargers like this. I think they are selling for under $20. Do not buy a $10 charger. They can be so bad they are dangerous.:

All my 18650 cells were free - liberated from the recycling bins in various shops/supermarkets - my thread seeking to gain more knowledge about the large spread in claimed capacities I'd found was relegated to the "Not advisable".

From my POV, salvaged cells have already been run in - if they were prone to going bang/venting with flaming gas, the previous owner would already have found out.

Naturally if I found a lithium pack with evidence of destructive failure, I'd throw it back and keep walking.

 

[Roscoe01]

All my 18650 cells were free - liberated from the recycling bins in various shops/supermarkets - my thread seeking to gain more knowledge about the large spread in claimed capacities I'd found was relegated to the "Not advisable".

From my POV, salvaged cells have already been run in - if they were prone to going bang/venting with flaming gas, the previous owner would already have found out.

Naturally if I found a lithium pack with evidence of destructive failure, I'd throw it back and keep walking.

I don't think we need to suggest that the op goes Dumpster diving for a battery for his sub ohm mech. No offense meant but I would call that "not advisable". OP doesn't have a multimeter (yet) let alone a way to test used batteries.

best choice here is for him to buy the best battery his budget will allow from a reputable seller that will fit his needs. And our job is to point him to the safest options so he can make an educated decision.

 

[ian-field]

I don't think we need to suggest that the op goes Dumpster diving for a battery for his sub ohm mech. No offense meant but I would call that "not advisable". OP doesn't have a multimeter (yet) let alone a way to test used batteries.

best choice here is for him to buy the best battery his budget will allow from a reputable seller that will fit his needs. And our job is to point him to the safest options so he can make an educated decision.

All I'm hearing ATM, is the market is flooded to bursting with fakes - and some dangerous ones at that.

I'll stick with the ones that have already been run in by someone else thanks!

And my thread was seeking knowledge - anyone who says that is "not advisable", is even more so themselves!

 

[supertrunker]

They discarded them why?

Ohmmeter and not being cheap with batteries seems the way to go!

T

 

[SonHouse]

All my 18650 cells were free - liberated from the recycling bins in various shops/supermarkets - my thread seeking to gain more knowledge about the large spread in claimed capacities I'd found was relegated to the "Not advisable".

From my POV, salvaged cells have already been run in - if they were prone to going bang/venting with flaming gas, the previous owner would already have found out.

Naturally if I found a lithium pack with evidence of destructive failure, I'd throw it back and keep walking.

Sounds like it belongs in the "Not Advisable", glad they put it there. You have a huge hole in your logic in that the cells were previously used in an apparently suitably designed circuit but after an unknown amount of wear and tear on them, you're putting them into a completely unrelated circuit without having a clue as to what their operational parameters are. And, you think this is safe because they didn't fail in a properly designed circuit you don't know enough to recreate.

 

[SonHouse]

I am using a mechanical Mod with sub ohm coils.
I don't have an ohm meter but I am running dual coils each with 6 wraps around a 3/55" screwdriver. 28 guage kanthal wire

What is the best battery?
I am thinking of getting an 18650 VCT 5, which is a 2600 mah.

I remember reading something a while back that if you are sub ohm you shouldn't go above 2000 mah but I am not sure.

Any help is appreciated and if anyone knows where I can get inexpensive batteries because I don't trust any of these local vape shops.

One place just tried selling me one of the VCT 5 batteries for $19 and a charger for $23. It seemed a bit overpriced.

As others have mentioned, being able to test your coils before using them is a prerequisite. Mechanical mods do not have safeties built in like regulated mods do so it's on you to make sure that they are safe. Battery safety is the number one topic to study before jumping into the mech world, especially with a sub ohm coil you can't measure. And to properly measure sub ohm coils, a voltmeter is actually the best approach since the inaccuracies in the e-cig based meters can become critical.

 

[Roscoe01]

Your repurposed batteries are no different than many of the counterfits on the market. A good portion of the fakes are used batteries that are merely rewrapped and sold as new.

I am all about being thrifty and repurposing things but I will never suggest anyone else do something that may be unsafe.

Hence the reason I posted a link to a site that I am 100% positive does not sell anything counterfeit and stands behind that promise.

 

[ian-field]

They discarded them why?

T

In 99.99% of cases, one or two weak cells render the whole pack unserviceable.

 

[GoochMan]

Thanks for all the info
looks like I have some homework to do.
I didn't just start building.
I have been using those same coils with IMR 18650 -3.7V - 1600mah batteries for about a year now.
I just need new batteries cause these dont seem to hold a charge for very long anymore.
I will get an ohm meter now and figure out the amp draw moving forward.

 

[ian-field]

Thanks for all the info
looks like I have some homework to do.
I didn't just start building.
I have been using those same coils with IMR 18650 -3.7V - 1600mah batteries for about a year now.
I just need new batteries cause these dont seem to hold a charge for very long anymore.
I will get an ohm meter now and figure out the amp draw moving forward.

There are a few hidden traps for the DIYer!

One of the first you'll meet is the resistance of the DMM test leads, assuming you find a DMM with close enough resolution to read the coil resistance - you also have to take into account the test lead resistance, touch the prods together and see what it reads - then subtract that value from what it reads for the coil.

Sub-Ohm coils draw a few amperes, at that much current the test lead resistance can drop a significant proportion of the battery voltage - as can the shunt in the meter itself. This volt drop is subtracted from what ultimately ends up across the coil - that means less current will flow while taking the measurement than with the coil connected straight to the battery.

 

[Roscoe01]

GoochMan I am unsubscribing. Feel free to pm me if u have any further questions.