High Discharge 18650 cells as buffer tube batteries?

Hangtight

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What it says on the tin. I had a measure and it'll fit. The high capacity  (2400mah) Sony ones have  a Sony published 40A discharge voltage graph. The 3400mah Samsung ones are supposed to be good for 25A continuous. And the best bit is I can buy 4 for about the same as a 1450mah buffer tube lipo.

Anyone done anything similar, or am I blazing a trail?

 
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Those are better prices than what I paid for the Nuprol 1450mah ones I'm using now (which hit the cliff after about 1000mah). The Samsung ones actually measure at the stated capacity so I'm looking at twice the capacity for the sake of a bit of twatting around with heatshrink.

My only concern is I don't know how much current pull a ASG CNC 30k pushing 13:1 gears and a M100 spring generates.

 
My only concern is I don't know how much current pull a ASG CNC 30k pushing 13:1 gears and a M100 spring generates.


Find out - this is the same mofo bad boy I use:

http://www.ebay.co.uk/itm/Watt-Meter-Balancer-Digital-60V-100A-Voltage-Power-Analyzer-Tester-UK-B0F8-/172404167726?hash=item282416d42e:g:MD4AAOSwB09YJBnZ

plug it in between ya gun & 7.4v lipo - fire on auto for a short burst noting the amps

(it doesn't stay on screen - starting amps is a bit higher but should get a constant reading very soon once gun is cycling on auto. Obviosly it drops to zilch once gun stops but you get the idea)

there are others a bit cheaper but this comes with deans n crap ready to go

suppose this will do:

http://www.ebay.co.uk/itm/Digital-LCD-60V-100A-Watt-Meter-Battery-Balance-Power-Voltage-Checker-Analyzer/401185896860?_trksid=p2047675.c100623.m-1&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40656%26meid%3D96e37bfceeaa43b5883f7beea2e3e003%26pid%3D100623%26rk%3D2%26rkt%3D6%26sd%3D172404167726

but add your own male/female deans & wait for it to arrive from China

yes you can use a loop type amp meter or tester I guess but they ain't cheap

rough guess on a 30k & 13:1 maybe 21 amps but who knows if my meter motors n setup is pulling the exact same spring etc...

plus my high quality meter could be way way way out of whack

I just use it to confirm stuff when fine tuning motor height by ear/meter as well as hopefully getting my shimming height correct

(or as near as I possibly can within some reason - not drilling loads of holes or take it to engineering lab or stuff like that)

Those are better prices than what I paid for the Nuprol 1450mah ones I'm using now (which hit the cliff after about 1000mah).


Just make sure you try to order from either UK or EU

very easy to screw up and inadvertently order from Hong Kong instead

Then wonder where the f*ck are those lipo's - ooooh crap hope I don't get hit with import duty too

(I have done this once - dohhhhh)

 
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SOLD!

Anything that helps take the guess work out is a good idea. I take it with motor height tuning you're simply looking for the lowest current draw?

 
SOLD!

Anything that helps take the guess work out is a good idea. I take it with motor height tuning you're simply looking for the lowest current draw?


Indeed - well in theory....

Some have said when wild guessing the height just by ear they found there have been 2 "sweet spots" but can't see that, but they noted one sweet spot sounded good but amps was high

The second sweet spot sounded great too but amps quite a bit lower

Maybe a badly suited bevel/pinion was meshing sweet a little too high/low

Should check then pinions and bevel more closely I think - jeez some of them mesh f*cking badly

(my thoughts you should only be guessing stuff like bevel height if you are a Vulcan coz Mr Spock's guesses are $hit hot)

The point is you have a pretty good idea the motor height is correct or nigh on

However which way to do the shimming - you got a pretty good idea that motor height & bevel height is correct

Then 1/4 turn left or right to fine tune it "should" produce a better/worse sound or less shrill

So in theory - which I feel does correlate if the gears are meshing correctly & smoothly

The smooth gears meshing correctly produce less friction & shrill which in turn draws less amps

Less amps or current draw means stuff runs cooler and your battery will last last longer

Plus should be running at its fastest possible speed/rof if there is less friction too

Gun should perhaps last longer I guess though I'm not offering no lifetime guarantee crap

But it "should" just cycle more efficiently in all aspects of the drive chain

(maybe sounds a bit tarty but I think; " Every little helps " as Tesco say)

Whack in a high speed motor over a torque or balanced motor and you really see amps ramp up as well as stuff gets warm

Bad shimming does the same thing too making stuff run hot & fuses blow etc....

I don't think for one sec that amps are everything - but being sure the height is correct to begin with

THEN both sound & amps can help fine tune the tiny tweak on motor plate just a smidge

(young people look at you weirdly when you say the machine/car/gun is talking to you)

If it still sounds & runs crap with high amps then that is the motor angle

(often that can happen when people change M4 grips for a crappy snide ACM grip)

best grips for angles usually end up being the ones that came with the gun

some aftermarket ones can be f*cking dire I have found

Ooops - wall of text again sorry, you know this already, my bad

Ergh yeah lower amps usually goes hand in hand with a sweet bit of shimming - motor height or drive chain

BTW for what it is worth, I am no expert but watching really clever bastids like Rogers helps a lot

TBH - sod going into as seriously deep as he does, I don't fully agree with everything he does

BUT - he really covers everything nigh on and if we can get boxes just half as smooth as his

well I think we have done alright & if on the odd occasion I get near 75% of his smoothness

Well I'm very very happy.

Think only the original James Bond could be smoother....

I7cmpyY.jpg


(soz but I just love this repost)

 
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This idea has legs! I've measured the current draw of two different AEGs. One is an ASG CNC 30k pulling an M100 through 13:1 gears... 19.5A. The other is a Lonex A1 Supreme pulling an M110 on 18:1 gears... 18.8A. Samsung 25R 2500mah cells have a maximum continuous discharge of 22A with a 35A peak, which means I can build a 2500mah pack that fits in the buffer tube for around a tenner, including the connector for the balance circuit.

 
ANy idea what the C rating on your 18650 cells is? Most I've seen are too low to really be viable as an airsoft battery.

 
Even more promising are the new 21700 cells that tesla /Panasonic and Samsung are just starting production of. 5500+mah and discharge rates that are suited to electric vehicle use along with rapid charge capability.

 
One is an ASG CNC 30k pulling an M100 through 13:1 gears... 19.5A. 


rough guess on a 30k & 13:1 maybe 21 amps but who knows if my meter motors n setup is pulling the exact same spring etc...




Wasn't a bad guess eh ?

Each build is slightly slightly different, spring & barrel length, bearings, bushings shimming etc...

plus motors etc....

You using a 30k motor, so to me is slight quicker balanced type motor

SHS Torque is a balanced motor really which output seems to be between 26k & 29k depending on source

(I'll go with an average 27.5k I guess)

Then you got Krytac's 20k & 30k motors etc....

Your Lonex A1+ is a quicker motor pulling similar amps on modest std 18:1 gears

On a lamer stock motor you would be drawing say only 13 amps or the Lonex on 12:1 gears 24 amps & getting warm

The amps in ya gun sound about right to me indicating shimming is good etc...

(not that I doubted you for a sec)

Anyway, Amps aside - I have slight reservations as to if these batteries will provide the raw grunt anything like LiPo's

Avoid LiFe's - they are just not worth it imho

You would think they would be ideal for a bridging level between 7.4v & 11.1v LiPo @ 9.9v

But in reality I found they offered very little extra real grunt over a 25c 7.4v in a mildly tweak gun

Perhaps they performed better in a std stock gun but when tested in a slightly beefed gun they showed little improvement

And because of the poor performance of the LiFe's leads me to wonder how much raw chemical energy other battery types have

interesting video:






However the guy does say it doesn't have the same raw grunt or C or burst as the Lipo

Go to say 6:30 and guy says it hasn't same grunt as the LiPo

But it might be ok for modest builds - much like the LiFe battery type I found

keep us updated how you get on though but I still think LiPo's are still the way for airsoft

just trying find the right size/shape LiPo that can be a major headache sometimes

(easy used a big fixed stock & carry ya lunch in there too or just duct tape the bastid on ya gun)

Certain batteries will suit certain applications is what I feel

RC stuff & their motors even in use is nothing like airsoft motors

RC's get going and in general that is it - well yeah they fluctuate in speed control but...

Nothing like AEG's when you think about it

Just shifting stuff is one thing but the spring's compression builds placing more draw even though the sodding motor is moving now

Each cycle even on full auto the motor is running freely as piston is released, then builds up & up again to a point where the poor motor/battery's nutz almost drop off dragging the piston back the last few teeth

Well ok - not quite so vividly put perhaps - but you see they difference in use that the airsoft battery is going through and the vast variation in load increasing & free running until the load increases again etc...

To me I am imagining a TESLA being driven to work with say 12 foot high speed bumps all the way

Yeah let's see how much grunt & how long the recharge points are now

A bit OTT I'll agree but that is kind of like what is happening inside an AEG box as it cycles

Which is a lot different to a little RC whizzing around

Soz - dramatic example I know but these peew peew toy guns are much more demanding than RC's

 
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Those NCR cells are high capacity but only have a peak current of 6.8A. A quick look at the discharge graphs for the two different batteries shows that the voltage drop for the Samsung 25r at 20A is quite a lot less than the drop for the NCR @ 6.7A, which might suggest a different chemistry. I'm going to see if a can find the discharge graph for a comparable lipo and see how they stack up.

 
So I'll get a couple for the sake of a tenner and see if it works. Worst case is I wind up with a couple of extra torch batteries. ;)

 
Well, ordered some. I'll let you know if it works out. If it doesn't then I may have some torch batteries for sale...

 
Well, it works. Trigger response seems the same, and the measured rate of fire is the same. The few short bursts I've tried don't seem to cause any significant rise in the battery temperature. As soon as I get a chance I'll try a proper stress test, probably by taking it to a skirmish and seeing how it performs.

 
Post is back from the dead. The packs work. The batteries don't get hot even if I'm being trigger happy, and they're good for pretty much the full stated capacity. So that's a win. :)

 
I have used both lipo and liion 18650 batteries for 400 fps aegs no problem. At that time their capacity and C rating were a bit low, but still better than a 7 cell nimh.

 
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