first mod build, altoids tin with a dna20

[RicModMaker]

I didn't take many pictures tonight, I wanted to make sone head way and get this done and out of the way as the dna20 no longer interests me.

The original plan was to power this with a 6000mah feilong 32650 I have lying around and build up a chassis out of a nice piece of timber and some brass.

The problem is, I'm vaping at 25watts or more on my day to day mechs, so I'm back to the issue of vw not really cutting it for me.

Having been chatting with some like minded lunatics, there are other plans now afoot, but it did leave me with the dilemma of a £45 board lying about in need of a home.

Anyway I got a bee in my bonnet today and decided to start looking at things. I still have a tobacco tin that will take an 18650 battery case, and B1mble sent me some bits down in an altoids tin at Christmas.......


A quick test fit and the dna20, 18650 case both fit in and leave room for micro switches, 510 connector and wiring, game on.

So, I've got a bit of the drilling and cutting done, concluded I need another small micro switch for the firing button as the big anti vandal switch wont fit and wrote off the 510 connector, I wasn't all that impressed with it anyway so I'll look at building something for that, but I did get the battery tray ready for gluing up so here's the start of my first build, I'll update when I've made further progress, which will likely be when I've aquired more parts, although I will get the tin fully drilled ready for the required bits.

So, the tray. I had a broken 18650 case lying about, I drcided this would be a good home for it, it will be epoxied into the altoids tin when I know everything works and the top will just push on to insulate the cell connections.



There's the pos and neg contacts, note the bumps to allow flat top cells, the 20g silicon cables have been passed through a small hole drilled in the top corner of each plate, twisted and soldered in place.

Here's a mock up of the tray, ready for the plates being epoxied in place.

Really what I'd like to do is use a pack or make a pack so there's double power and double mah so a 2s2p arrangement but if they don't last very many cycles and cost too much, I may as well use 2 x 18650 in serial.
So really interested in finding out the cycle life of these lipo cells.
I had the silly idea of using a nut as a 510 connection but for the life of me, the correct thread size but is impossible to find. The only way I could work out to fabricates 510 female was to buy a tap and die set. I did neither in the end but might invest in the future. Best of luck.

 

[doobedoobedo]

Any info on the number of charges these batteries can take? Are they comparable to 18650 batts?

As with all things it depends how hard you push them. I would expect them to at least equal 18xxx batteries as they are after all just a different kind of Li-ion. My everyday mod has been, and continues, to go strong on them since the beginning of January with no sign of degradation.

You can pick up 3.7v "saddle packs" their about thiry quid but they are a self contained unit capable of 150amps or so and being between 4600mah and 6000mah........ not that I've been looking or anything....

The best way to search is 3.7v lipo pack, you will find lots of tiny things for rc helicopter's though so do make sure you order the right thing.

Thanks for the kind words guys. I've been trying to decide if I can make a 510. I think I have a design figured out using a piece of the brass i have, I may get away with using a bit of the lexan I bought in and I havw some brass I may be able to turn in a drill and use a file as a human lathe arrangement, I'll probably use two small orings to give a small amount of movement to the pin. It would be good to do that because I could have it built this week. If I have to order stuff I have to wait till payday. The other solution is I think my friend has some broken ego batteries.....

Good idea about the saddle pack . If you do want to build a pack from single cells, I've used these too http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=34561 to make a 3000 mAh re-homed Vamo. I must admit my main driving force in the ones I choose is size, they come in such a variety of sizes there's always one suitable. Bare cells are much easier to deal with than the 750mAhs I used in the monster too as you don't need to remove any coverings (which are firmly stuck on) first.

 

[gords1001]

I'm hunting for now. I like your mosfet build so my searches are around those.

Seedy, going 2s (7.4v) makes it much easier to find big capacity packs, personally I want high capacity and high current, I'm struggling to find dc - dc converter boards that will give more than a few amps. The raw simplicity of the mosfets and using any atty I lay my hands on really does appeal so thanks to doobedoobedo for that build.

I think I've figured out the 510. My brass is 1/8th, the lexan is 1/8th, I'm going to need three strips.

One brass tapped m7 x 0.5mm (yes I bought a tap)
One lexan clearance hole for an m4 brass pan head screw
One lexan tapped m4

The screw wil have an oring on each side of the lexan and a couple of nuts to lock it in place. The whole sandwich will be built around the edge of the altoids tin, , I'll use two brass pan head srews and nuts to secure the lot. Should make for a secure 510 connector that doesn't flap about, one of the complaints I've seen leveled at many tin mods and also the reason I broke my connector trying to rectify that. I might be able to pick up a monentary switch from maplin, I'll look into that, the screws I have at work, just need to pick them up.

All this is probably double dutch so I'll take some pictures when I build it.

 

[RicModMaker]

As with all things it depends how hard you push them. I would expect them to at least equal 18xxx batteries as they are after all just a different kind of Li-ion. My everyday mod has been, and continues, to go strong on them since the beginning of January with no sign of degradation.



Good idea about the saddle pack . If you do want to build a pack from single cells, I've used these too http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=34561 to make a 3000 mAh re-homed Vamo. I must admit my main driving force in the ones I choose is size, they come in such a variety of sizes there's always one suitable. Bare cells are much easier to deal with than the 750mAhs I used in the monster too as you don't need to remove any coverings (which are firmly stuck on) first.

If I do a 2s2p configuration with these, will it up the amps to 40?
I reckon 2000mAh and 7.4v should be ample for my mod.

 

[doobedoobedo]

Any info on the number of charges these batteries can take? Are they comparable to 18650 batts?

You can pick up 3.7v "saddle packs" their about thiry quid but they are a self contained unit capable of 150amps or so and being between 4600mah and 6000mah........ not that I've been looking or anything....

The best way to search is 3.7v lipo pack, you will find lots of tiny things for rc helicopter's though so do make sure you order the right thing.

Thanks for the kind words guys. I've been trying to decide if I can make a 510. I think I have a design figured out using a piece of the brass i have, I may get away with using a bit of the lexan I bought in and I havw some brass I may be able to turn in a drill and use a file as a human lathe arrangement, I'll probably use two small orings to give a small amount of movement to the pin. It would be good to do that because I could have it built this week. If I have to order stuff I have to wait till payday. The other solution is I think my friend has some broken ego batteries.....

If I do a 2s2p configuration with these, will it up the amps to 40?
I reckon 2000mAh and 7.4v should be ample for my mod.

Yes they'd be good for up to 40A, but as I said before for 2S packs to make 2S2P I'd parallelise 2 pre-built ones like these:
http://www.hobbyking.com/hobbyking/...000mah_2S_25_50C_Lipo_Pack_UK_Warehouse_.html
or these:
http://www.hobbyking.com/hobbyking/...ah_2S_7_4v_20C_Lipoly_Pack_UK_Warehouse_.html
or these:
http://www.hobbyking.com/hobbyking/...y_1000mAh_2S_20C_Lipo_Pack_UK_Warehouse_.html
the choice is wide, look at the dimensions of the pack (remember to add some space for wires) and get what suits.

 

[gords1001]

Updating the op with a couple of shots of last night's progress, been busy today but hope to start on the new 510 tonight.

 

[Chegs]

I'm struggling to find dc - dc converter boards that will give more than a few amps.

I have posted this a few times before(one in its own thread)but the NAOS Raptor http://uk.mouser.com/ProductDetail/GE-Critical-Power/NSR020A0X43Z/?qs=DWPgn/G9gkxYgP6PIW5L/A== will run to 20A,and as can be seen from my link,cost just £13 ish each.

 

[gords1001]

That certainly seems like the ticket, , I've got lipo packs that will run it already too, if their time in hibernation hasn't killed them that is. I'll look forward to a build with one, I really want to do a nice timber and brass box mod with a honking power output.

 

[RicModMaker]

Im still after a potentiometer board with a knob. I've got an ft one coming but would rather have a knob to twist. Any advice on that peeps?

 

[gords1001]

I've already got a knob to twist, you get shouted at in public though