Battery Advice, please

[Junglespy]

Hey there, I'm torn between two versions of the same gun (being the CA M15A4) and the only difference between them is the fact I can have the adjustable stock (which I prefer the appearance of) or the full stock that can fit the larger battery types.

What I'm asking is does the battery size affect the ROF or just the duration of the battery life?

I don't want to pick up a 9.6v small battery for the sake of the aesthetics and compromise on the ROF - I'm more than happy to buy two 9.6v smaller type batteries and use the two of them throughout the day if the ROF is equal to the larger type.

Hope this makes sense and any feedback will be cherished.

Regards

Junglespy

[Roxy]

Re: Battery Advice, please

Higher volatge means higher rate of fire. Bigger battery means it lasts longer.

So basically a small 9.6v battery will give a higher ROF than a large 8.4v battery. Make sense?

[BALBOSA]

Re: Battery Advice, please

yeah dude what roxy sais go for the sliding stock :D

[Junglespy]

Re: Battery Advice, please

Thanks very much both of you.

That's exactly what I needed to know. Decision made!

[Fizzy]

Re: Battery Advice, please

Actually, you'll likely find that you get a higher RoF with a large 9.6v battery than you will with a small 9.6v battery due to the larger battery having a larger discharge rate

Infact, I remember someone on here mentioning they had no noticeable difference in RoF between using a large 8.4v battery and a small 9.6v battery

However, if you prefer the sliding stock, you could always run with a 7.4v lipo if you want to maintain a decent RoF

[Andy8746]

Re: Battery Advice, please

Your best option would be to get nun chuck battery's for an m4 front wired gb

[BALBOSA]

Re: Battery Advice, please

yeah i use nunchucks in my m4 and its always been a good rof. when using the sentry i got amazing rof from a nunchuck 8.4 small cell it was incredible obviously thats part down to the m120 motor

[Roxy]

Re: Battery Advice, please

Actually, you'll likely find that you get a higher RoF with a large 9.6v battery than you will with a small 9.6v battery due to the larger battery having a larger discharge rate

Infact, I remember someone on here mentioning they had no noticeable difference in RoF between using a large 8.4v battery and a small 9.6v battery

However, if you prefer the sliding stock, you could always run with a 7.4v lipo if you want to maintain a decent RoF

That doesn't seem right to me...I could be wrong though, it happens lol.

I have always been told voltage and size are 2 very seperate thing

[Junglespy]

Re: Battery Advice, please

I used to use a large 8.4v in my MP5 beforehand and was happy with the ROF so if the M4 maintains a similar ROF with a smaller 9.6v then I'll have no complaints.

My main issue was that I didn't want to see a dramatic decrease in ROF for the sake of the look of the gun.

Regarding the nunchucks batteries, I'll likely get a small battery with the value package that comes with the gun so will look to purchase a seperate nunchuck battery

http://www.**************.co.uk/html...000afp-hh.html

Would this fit in the handguard of the M4 then?

[BALBOSA]

Re: Battery Advice, please

I used to use a large 8.4v in my MP5 beforehand and was happy with the ROF so if the M4 maintains a similar ROF with a smaller 9.6v then I'll have no complaints.

My main issue was that I didn't want to see a dramatic decrease in ROF for the sake of the look of the gun.

simply put....you wont :D go for the tac stock its allot more usable

(coming form an m4 user )

[Roxy]

Re: Battery Advice, please

Well a small 9.6v WILL give you a good ROF. Whether it's as good as a larger one I'm now not sure. I hate when people make me questions what I thought I KNEW lol.

I use small 9.6v batteries all the time and I've never felt like my ROF was low

[Fizzy]

Re: Battery Advice, please

That doesn't seem right to me...I could be wrong though, it happens lol.

I have always been told voltage and size are 2 very seperate thing

The are seperate, but the battery capacity affects the discharge rate (amps) the battery can supply. Here's an exctract from Infected's lipo page that explains it better than I can

Number two has to be one of the most annoying things I hear about lipos. Everyone is afraid of the big bad lipo battery! Why do people think that a lipo will blow up your AEG? I just don’t get it. Let’s learn some math and understand why this is total nonsense!

First we must understand a thing called discharge rate. This is the rate at which current flows out of the battery. Manufacturers refer to this as the “C” rate of the battery. So if your battery specs say that you have an 11.1v 2200mAh 25C battery, then you know the discharge rate is 25C. Now what does that mean? Well, let’s convert that to something we can understand. To convert the “C” rate to amps (a measure of current), we just use this formula:

C Rate x Capacity (in amp hours) = Discharge Rate in Amps

So let’s look back at the battery we were just talking about. Using the formula we have 25C x 2.2Ah = 55A. Now hold up a minute and don’t freak out when you see that 55A rating. We’ll get to that in just a second. What you need to know is that 55amps is what that battery is CAPABLE of producing. Now let’s switch gears and see what that NiMH battery you have is capable of producing. Most NiMH cells used in Airsoft can discharge with a C rate of up to 12C. Hum…. see where I’m going don’t you? Keep reading. So let’s look at an average mini battery that might come with an AEG; say a 8.4v 1400mAh NiMH battery. Using the formula above we find that it is capable of discharging 16.8amps continuously. Wow, big difference.

Okay, enough of the math, what does that mean to you and your AEG? Every AEG needs a certain amount of current to run. This can vary from setup to setup due to different requirements of the motor and the load it has to drive as determined by the spring strength and gear ratios. Let us look at my M249 for an example. Drivetrain-wise, here are the specs:

Guarder High Speed Motor
Madbull M120 Spring
Standard Ratio Gears
8mm Bearings

Now this gun requires about 22A to drive it, and since it’s a PARA version, it only houses a mini battery. WAIT! Didn’t we just find out that the mini battery in the above example only can put out up to 16.8 amps!?!?!? That’s under powering the gun by about 23.6%! So what can we do to increase the performance given the tiny space we have to fit a battery? Well, we can put the battery someplace else and use a larger battery, but that might not be an option. Then we can increase the voltage from 8.4v to 9.6v. Well in this case, there is room to add the extra cell. Adding more voltage will increase the ROF and provide more power to the system but you might not have room for the extra cell either; there must be a better way. Enter Lithium-Polymer batteries; stage right. Lipo batteries are able to fit higher capacities and higher discharge rates into smaller packages than a traditional NiMH or NiCad battery. So let us revisit our space and current conundrum.

We need 22 amps of current to drive our system (AEG’s drivetrain) at 100%. So let us use a 7.4v 2200mAh 25C lipo battery. That has a discharge rate of 55A. Of course, the gun only needs 22A…. and as such WILL ONLY DRAW 22A. The gun can’t and will not use more current than it needs. It will however, try to pull as much as it needs. So when you’re putting that mini battery we talked about earlier in there, we’re over taxing the motor and the battery as the motor tries to draw the full 22A out of something that can’t supply it. With the lipo, we have only used 40% of it’s capability; thus not overtaxing any part of the system! Did you also notice we’re only using 7.4v to drive the system? Nice huh?