Is 7.4v 20c/3000mah reciver battery enough for Airsoft?

[ThunderCactus]

FYI if you can add a mosfet to your SAW it will make your battery efficiency ridiculously good
I'm getting around 400mah/box mag on my 249 with lipo/mosfet/triple torque gears at 1400rpm and 380fps

[Kos-Mos]

Originally Posted by blackjack21

So does that mean this double pack is only going to give me 30amps as opposed to 60? 10c x 1500mah for each pack x2 packs? This still should be doable as most 9.6 nmh only run about 22 amps...


Sadly those bigger packs are too big for my gun, this was the only one over 2200mah that would fit...

It is still technically a 20c pack.

But because that is driven by two smaller packs, they are more prone to failure.
It's kinda hard to explain (especially since I just work-up), but two packs never equal a single larger pack. That is the reason they mark it as receiver pack. It's good for 5-10 amps at most, what ever the C rating says.

What are the dimensions of the space you have for your battery?

[m102404]

One big bag of milk = big long non-stop drink

Half a dozen little milk cartons = empties quickly and you need to stop drinking to have more ready to go

*see...battery stuff is simple....

[blackjack21]

It's kinda hard to explain (especially since I just work-up), but two packs never equal a single larger pack. That is the reason they mark it as receiver pack. It's good for 5-10 amps

I sure hope not I just ordered 2 of these batteries based on the recomendations from yesterday.

They shipped today....

Not sure how that's even possible.. If these were even 2 10c packs with 1500mah each that's still 15 amps each. which should = 30 amps no?

That reciever pack would basically barely fit. (they are going into the nutsack of a stoner lmg). If this does not work I am basically out 40 bucks and stuck having to buy some 2200mah lipos.

[Kos-Mos]

Well...

.20g bbs they sell at Canadian Tire are still .20g and 6mm... yet they are crap.

The same applies to batteries. There is no magic at work. If the 2200mAh is the same voltage and same size as the 3300mAh, there is something else that is different.

Theses are marked and marketed as receiver packs. Even though their theorical rating is 30C, they are not.

Theses packs will work fine, but they will bloat very quickly and you will have to replace them soon. The size of the wires on the pack is a give away... if the wires can't handle more than 10A, how do you want to get more than that to your gun?

[blackjack21]

Well Fudge! :rocket:

...

[ScooterVauto]

I really like the Team great hobbies lipos
35 and 50 C continous rates (NOt burst)
under 40$
charge at 9 amps (reccomended)
I love em
http://www.greathobbies.com/producti...d=TGHL32002C35

the advantage to the pack you chose is as mentioned, its 2x2cell.
in theory you have 2 7.4s, if they have 2 seperate connectors that is.

so you can still use them till they die.

[XZIVR]

um. Everybody is caught up on the mah and c rating. Take another look at the battery guys.. Look at the leads. They're ~22gauge wire, typical for a receiver battery. Yes the CELLS are rated to drop some serious current, but the WIRES are woefully under sized for this sort of application. Depending on the gun it's used in, those leads could pose a serious problem.

Originally Posted by Kos-Mos

The pack is a 2s2p. That means that it's actually two packs (4 cells). And since it's rated 20C constant, it means that theses cells each are rated 10C.

No, actually the cells are 1500mah 20C. 1500mah 20c + 1500mah 20c in parallel makes 3000mah 20c. Add that in series with another group and you get 2S2P. The reason they do that is to make the battery meet certain physical size requirements without making individual cells too thick. In any event, the math works out that the battery as a whole is still 3000mah 20c. Hope that makes sense, draw it out on some paper if it doesn't.

[ScooterVauto]

wow I didnt see that, the power leads are very small.
As mentioned they might burn up under heavy load.

[ThunderCactus]

You'd also get next to no current out of them lol

[XZIVR]

Yeah, now, if, and I stress, IF you know what you're doing, you can go out and grab yourself some quality 16ga or better wire and solder that directly to the cells. Then re-heatshrink the battery because you'd have to cut it all up to get to it. It can be done, I've done it before, but there's high potential to burn your house down if you don't know what you're doing.

[ScooterVauto]

I had thought about that, I think Id almost be willing to try LOL
Looks like I'll be hitting the hobby store for some 16 or 14 G Silicone noodle wire LOL

I wonder if Blackjack wont mind Clear shrink wrap
(picked some Clear 3 inch for rewrapping Large batteries that had the wrapping tore up).

And to answer a previous statement -- The Stoner Will have a Simple mosfet unit - I Just have the assemble said mosfet

[XZIVR]

My best advice is make sure to tin the new wires very well (apply flux to them before tinning), and be very careful applying the new heatshrink. My first time doing it I ended up puffing the battery slightly from the heat I applied. Slow and steady is the way. Thinner heatshrink is also better because it takes less heat to activate.

[ScooterVauto]

ya the heating of the wrap is the only think truley bugging me
lipos hate both hot and cold so you cant precool the battery in the fridge before putting on the wrap and the other side, using semi direct heat to melt the wrap on a battery that doesnt respond well to hot LOL

although i have heard that RC folks tend to store them in the freezer

[Kos-Mos]

Originally Posted by XZIVR

No, actually the cells are 1500mah 20C. 1500mah 20c + 1500mah 20c in parallel makes 3000mah 20c. Add that in series with another group and you get 2S2P. The reason they do that is to make the battery meet certain physical size requirements without making individual cells too thick. In any event, the math works out that the battery as a whole is still 3000mah 20c. Hope that makes sense, draw it out on some paper if it doesn't.

I will let you read that again...

Parallel = current doubles.
Serial = voltage doubles.

The "C" rating is a direct measure of the maximum current a pack can give.
In this case, the combined two packs are 20C, each pack will only give half of that maximum current. Otherwise they would mark the pack 40C since it would be better for marketing purpose. But it's not safe to run the pack at 40C...