Buffer tube question

[drew2r]

out of nothing more then my own curiosity, is there a battery that would fit inside a buffer tube on my M4 so that i could mount a stock that didn't have a battery compartment like a Magpul ACS stock?

[ujiro]

Lipo batteries! King Arms (among others) also make buffer tubes that have extra space cut out to fit these Lipo batteries more easily.

Talk to huang, he sells these.

[drew2r]

sweet deal, thanks man. I was headed down to huang's tomorrow any way so i'll ask him about it then.

[ujiro]

Haha perfect. Yeah he should have literally everything you need. Buffer tube, battery, charger, etc.

[drew2r]

i may need to upgread my internals if i run a lipo though cause i think my mecbox is some shit cyma re-brand china clone thing that I have yet to upgrade since i got my M4.

[ujiro]

Fair enough.

If I can just recommend. It won't be worth it as much to upgrade that box. if you have the funds available, I recommend a Systema prebuilt mechbox. They are absolutely incredible, and the price is great, considering you get a complete, 100% working mechbox with very high quality parts.

[drew2r]

that might be a plan in the future but for now i'll live with my crappy mecbox, it hasn't failed me yet *knock on wood*

[ujiro]

hehe :P. some of those china boxes just keep on kickin through anything, i've heard

[screwdriver]

run it on a 7.4v lipo and have no gearbox worries

[Corleone]

Originally Posted by screwdriver

run it on a 7.4v lipo and have no gearbox worries

I second that! This is because the lipo in itself won't mean a thing to your internals. It's the voltage and discharge rate combined that can cause wear. Preferably stay away from 11.1 lipos unless you get one with a VERY low (continuous) C-rate. 7.4v lipos is probably more than enough for more people.

Discharge rate = C-rate * Amps

Example: 7.4v 2400mAh 15C (continuous)
Discharge rate = 15 * 2.4 (2400mAh = 2.4A) = 36 Ampere continuous discharge rate
This battery will allow the motor to pull as much as 36 ampere continuously at any giver time. The voltage will still only be 7.4v.
The thing that many people misunderstand about the lipo batteries, is that lipos themselves can be too much for AEGs. This is not the case, and especially if you've upgraded your weapon with high quality parts. Why? Marui and many others, never made the weapons so that motor would get the discharge rate it "desired." Conventional batteries never provided such high discharge rates, and it was these batteries that the guns were designed for in the first place. So if you're uncertain if you're getting a too powerful battery, see if you can try something similar first. Also, many of the newer china clones can really take a beating, so don't underestimate your equip

[turok_t]

Sorry to hi-jack this thread, but I have a quick question re: lipos if you dont mind. Besides the higher rate of fire you get, and the smaller capacity to fit in the buffer tube, what others advantages does it have? Thanks

[Kos-Mos]

Originally Posted by Corleone

I second that! This is because the lipo in itself won't mean a thing to your internals. It's the voltage and discharge rate combined that can cause wear. Preferably stay away from 11.1 lipos unless you get one with a VERY low (continuous) C-rate. 7.4v lipos is probably more than enough for more people.

Discharge rate = C-rate * Amps

Example: 7.4v 2400mAh 15C (continuous)
Discharge rate = 15 * 2.4 (2400mAh = 2.4A) = 36 Ampere continuous discharge rate
This battery will allow the motor to pull as much as 36 ampere continuously at any giver time. The voltage will still only be 7.4v.
The thing that many people misunderstand about the lipo batteries, is that lipos themselves can be too much for AEGs. This is not the case, and especially if you've upgraded your weapon with high quality parts. Why? Marui and many others, never made the weapons so that motor would get the discharge rate it "desired." Conventional batteries never provided such high discharge rates, and it was these batteries that the guns were designed for in the first place. So if you're uncertain if you're getting a too powerful battery, see if you can try something similar first. Also, many of the newer china clones can really take a beating, so don't underestimate your equip

Sorry, but

WHAT THE HECK ARE YOU TALKING ABOUT?!?!

Using a too low discharge rated LiPo will simply turn your buffer tube into a pipe bomb!

Current is NOT controlled by discharge rate. It is controlled by supplied voltage AND load on the motor.

Simpliest electric formula ever:

I=V/R

Current = Voltage / Resistance (load)

Voltage stays about the same (you don't change your battery when shooting).

The resistance is increasing as the motor struggle to pull a spring. The spring is getting harder to pull as it compresses, so higher load = more resistance.


Now since you CAN'T control the current, the motor just drains what it needs.
If you battery can't give the current needed by the motor, the chemicals inside the battery will start to react to try to give more.

In a LiPo battery, the chemicals are turned into Hydrogen mostly. And temperature increases a lot.

LiPo batteries are made of Lithium and an electrolyte mixed in some plastic substance (polymer). Lithium is FLAMMABLE in contact of water, and there is enought water in the air (humidity) to make is burst in fire.

All this is wrapped in a thin aluminum sleeve and covered in plastic. Aluminum is not flexible.

Hydrogen is expanding as any other gases when heating (remember, the reaction causes heat). This causes the battery's sleeve to fail, releasing some hydrogen and letting some air come in contact of the lithium.

Lithium catches on fire. Guess what, hydrogen is explosive. (Hindenburg anyone?) Now all that is in an aluminium tube right next to your face...

Think about it.


Back on topic:

The only way to put less stress on your mechbox is to use a 7.4 LiPo (2 cells). It will make your rifle work like it was on 8.4v large battery.

[drew2r]

perfect, that's really what i need cause I want to but a mugpul ctr stock on my M4 with out having to re wire the damn thing to front or spend a bunch of money on upgrading internals to handle an 11.1 lipoly. hehe being a university student on a budget makes things interesting. oh does haung sell 7.4 lipos?

[Corleone]

Seriously Kos-Mos. Use the brain!

Now for what I wrote I meant it. Get a low C-rate battery if you're going for 11.1v lipos. Maybe 10-12C max. It will not explode. I can't believe that people really believe this sh*t. A battery will only provide as much amperage as it can provide. This is exactly the same as it is for conventional batteries aka. ni-cd and ni-mh. The AEG was designed with this in mind to begin with, and stock it's not always supposed to run as fast as some motors can go. Of course the motor will try to pull as much as it "desires," but will also run on less than that. This is why using a lower specced battery will also work.

Why get a low C-rate battery again? So he won't destroy his internals due to crazy high ROF. That's why I say, get a low C-rate if you decide to go for a 11.1v lipo, but preferably stay away from it and get 7.4v instead.

I never said that current was controlled by discharge rate. I said that current combined with discharge rate dictate ROF, which again means excessive wear on internals that's not necessarily built for it. I'm not sure what exactly you're trying to achieve, but your flaming of my posts is getting tiresome.

And please spare us all that cut'n paste from wiki. I don't think that many are interested in what happens inside the battery, as long as it successfully powers their AEG.

A high C-rate 7.4v lipo is really closer to, or even provides a higher ROF than a 9.6v conventional battery.

[Corleone]

This will absolutely fit inside of the buffer tube: http://www.khmountain.com/airsoft/pr...oducts_id=1171
It's a batter that can only provide 16.5A thought, and it's not even confirmed if it's continuous or peak discharge rate. Sadly it's one of the few lipos guaranteed to fit inside.

The next one is likely to fit inside: http://www.khmountain.com/airsoft/pr...oducts_id=1175

If you have a charger for it, I would of course recommend that you go straight for lifepo: http://www.khmountain.com/airsoft/pr...oducts_id=1184

Here are all the lipos/lifepos on that particular store: http://www.khmountain.com/airsoft/ad...i-poly&x=0&y=0

Sadly I 'm not happy with the store though. Ships awfully late, slow and horrible communication. Still has some of the cheapest batteries I've seen yet.