My Radio Shack box mod :)

[unholy79]

I've wanted to do this for some time, and finally pulled it off. My first attempt ran off a pair of AA's, but 3v didn't really do it for me. I needed more power, so I decided to try building one around a 9v power source. I'm going to make one that is Lithium Ion powered so I can recharge the batteries, but I want to see how long this 9v can hold out.



Basic setup is a 3"x2"x1" Radio Shack project box, momentary switch, on/off switch, 9v plug, 9v battery, atomizer port from an old Boge Revolution V2, and a Boge LR cartomizer. In all, it cost about $10 to make, and hits like a frieght train. I had cartomizers that didn't work right anymore (would get saturated with juice) - this brought them back to life. Not quite sure how long the battery will last, but I've got a 10 pack from Lowes so hopefully that will give me a bit of a reprieve before I incorporate some protected lithium ion cells.

Most likely I'm also going to order the M7x0.5 tap & die set so I can make my own atomizer ports as well... Don't get me wrong, I love my Boge RV2, but the quirks of a bottom feeder (flooding, etc...) were driving me nuts. For 1/5th the price I don't think I did too bad...

Part list:
1x 270-1801 3"x2"x1" Project box: $2.99
1x 275-1547 Mini SPST 0.5-Amp Momentary Switch $.92
1x 275-409 3-Amp SPDT Sub-Mini Slide Switch $1.84
1x 270-324 Heavy-Duty 9V Snap Connector $.53

Cheers,
--SJ

 

[TomCatt]

on innovation

Throw in 4 AAA NiMH in a battery holder and you'll probably be doing a bit better. Not sure what the amp draw limit is on a 9V alkaline battery. Four NiMH (AAA) rechargeable batteries under a ~3 ohm load will give ~4.8V and can handle the amp draw just fine. For LR upgrade to 4 AA NiMH batteries.

Check out these threads:
http://www.e-cigarette-forum.com/forum/battery-mods/106016-how-build-puck.html
http://www.e-cigarette-forum.com/forum/battery-mods/105465-now-puck-cheap-parts-easy.html

 

[Cool_Breeze]

Hi unholy,

Take a look at the mod I made from an RS Box...same as yours. It's on my profile page.
http://www.e-cigarette-forum.com/forum/members/cool_breeze-albums-dena-denali-tribute-mod.html

Also, look at this and the Denali.
http://www.e-cigarette-forum.com/fo...ena-vv-mod-denalis-lil-sis-step-step-how.html

Mamu also provides parts list somewhere.

 

[unholy79]

Wow, that's wicked! I like the voltage-meter gauge on it. So far the first 9V I ran lasted from about 6pm last night through noon today. It wasn't dead and still delivered vapor, but it must have been down around the 3-volt range because it wasn't much different from my Boge R2. Do you think 4x NMiH AAA's would be better than 1x NMiH 9V? I'm not as interested in variable voltage as I am in just 'set it and forget it.'

 

[Cool_Breeze]

Check the mAh on the 9 Volt batteries and on one AAA. The Volts add in series, but not the current over time. You'll have x mAh (miliAmperehours) at 6 Volts and y mAh at 9 Volts. The mAh should be a relative indication of how long each should last. ...seems I remember from taking apart a 9 Volt battery, that they are made from 6 small, skinney cells.

 

[TomCatt]

The 9V NiMH batteries are only around 200 mAh; not really enough power for ecigs.

All the NiMHs (except the 9V, which is actually made from 6 small nimh batteries) come off the charger at 1.4V each. Four give a total voltage of ~5.6V without an atty/carto. I've found that with a 3 ohm carto the voltage from 4 AAAs drops to ~4.8V. Like I said before others have used LR atties/cartos with 4 AA NiMH batteries.

AAA NiMH batteries are around 800-1000 mAh. AA NiMHs are around 2000-2500 mAh; both more than enough for ecigs.

Chances are with the 9V battery, the voltage "under load" (while vaping) is significantly under 9V; otherwise I'd imagine you'd get a burnt taste while vaping.

 

[unholy79]

I payed a visit to RS and picked up some of their NiMH rechargables, this location didn't have the '4 AAA' holder so I shoe-horned in a '4 AA' holder', managed to get it to fit (although the cover is now held on with a zip tie!). The performance is as good as with the 9V, just waiting to see how long it lasts before the cells need a recharge. Since the AA's have a higher mAh rating than the AAA's, I'll probably stick with them for the time being. Going to see about modding the cover so I can firmly attach it to the box. Once this mod is complete then I'm going to break out the dremel and make my own box from... something. I actually have a couple spare Antec aluminum 2.5" hard drive enclosures which might work... but one thing I've always wanted to do was make a box that I could install into an empty cigarette pack.

 

[TomCatt]

Don't be too surprised if you get at least 2 days with the AA batteries. If you want to stick with the nimh batteries, jump on eBay and pick up a second set (if you don't already have one) for cheap (I see batteries there for $0.99 each - I may pick up some myself). NiMH is a very safe chemistry and there's no problem with keeping the costs down with these. I accidentally shorted out my AAA NiMH batteries once and they got hot enough to make one of the negative battery springs sag. No harm, no foul; batteries even still work. The only thing is they don't hold a full charge for an extended period of time. If you're going to have a charged set set around for a week or more, throw them on the charger again before using.

 

[TomCatt]

Don't be too surprised if you get at least 2 days with the AA batteries. If you want to stick with the nimh batteries, jump on eBay and pick up a second set (if you don't already have one) for cheap (I see batteries there for $0.99 each - I may pick up some myself). NiMH is a very safe chemistry and there's no problem with keeping the costs down with these. I accidentally shorted out my AAA NiMH batteries once and they got hot enough to make one of the negative battery springs sag. No harm, no foul; batteries even still work. The only thing is they don't hold a full charge for an extended period of time. If you're going to have a charged set set around for a week or more, throw them on the charger again before using.

Sorry if anyone saw this post and got some of these eBay "deals". Just wanted to point out that I was looking over these batteries again this morning and checked out some reviews for the BTY batteries. These batteries haven't received any good reviews that I've seen. These and the other eBay "deals" actually weigh 1/2 or less than name brand AA nimh batteries; which apparently works as bad as it sounds.

I have some Tenergy AAA nimh batteries which seem to compare reasonably well with Duracell and Energizer nimh which I also have. Anyone looking for inexpensive AA nimh can check these out - Tenergy 10308 2600mAh AA NiMH Rechargeable Batteries 2600 mah 1.2V- 4 Pack

 

[caffeinator]

Powerex makes some nice batteries FWIW. I use them for my digital camera.
They came with my Maha C-9000 NiMh charger and they are very reliable.

Might look at the "new" IMEDION AAA 950mAh batts....

Maha / Powerex Corporate Site : NiMh Batteries and Chargers from Powerex

 

[unholy79]

I actually went ahead and ordered some trustfire 14500's from madvapes, i got maybe a day out of the NMiH's. Going to run a pair of the 14500's in it, installing a USB port on it too to keep it charged. Once that's done I should officially be done modding... but I doubt it.

 

[TomCatt]

I actually went ahead and ordered some trustfire 14500's from madvapes, i got maybe a day out of the NMiH's. Going to run a pair of the 14500's in it, installing a USB port on it too to keep it charged. Once that's done I should officially be done modding... but I doubt it.

How are you planning on wiring the 14500s up, series or parallel? Two 14500 in series = 8.4V and if wired directly to the atty, you're going to need a 4 or 5 ohm atty/carto or chances are the atty/carto isn't going to last long.

On charging - only set up 'on board' charging if wiring multiple batteries in parallel. AND you'll need a charging circuit to not overcharge.

 

[unholy79]

So far all of my experiments have involved wiring the batteries up in series, I got several days out of the Boge 2 ohm carto with the 9V mod, so I'm thinking 7.4v shouldn't be too big of a deal since with a 2 ohm carto its only getting around 5.4 volts when vaping (if my math is right).

As far as charging - I had previously looked at small lithium ion charging circuits, but I took a wild guess that the protection circuit on the battery itself would keep it from overcharging, but I also bought an external charger just in case that idea doesn't pan out.

 

[TomCatt]

The lithium-ion batteries will supply more current than the 9V alkaline battery. I would imagine that the vape directly off of 2 14500s in series is going to be a LOT hotter than off the 9V alkaline. I think, unless you ordered IMR 14500s, the limiting factor will be how much current the batteries will be able to deliver. My math says that with a 2 ohm carto and 8.4V (li-ions come off the charger at 4.2V) the circuit is going to try to draw 4.2A from the batteries; which I doubt non-IMR batts are going to deliver. This is going to at least put a strain on the batts and may trip the protection circuit. If you get batts capable of delivering the required amps, you'll be vaping at 35watts - I doubt the carto will survive that.

ON CHARGING - an intricate balancing circuit would be needed to have on-board charging of li-ion batteries wired in series. A simple charging circuit is good for batteries wired in parallel; but the protection circuit on li-ion batteries is there for protection not charging.

There are a number of threads in the Modding forum about on-board charging; please at least check these out before attempting this.

 

[unholy79]

I actually ended up wiring the batteries in parallel, and it works quite well. It looks like the protection circuit on first glance was actually preventing me from wiring them in series. Probably more to it than that, but it works and I'm happy.