Battery C Rating

[Logical Airsofter]

Hi all,

I am looking into buying a couple 7.4v 1000mah or 1300mah lipos.
I am just wondering what the C rating means and whether I should be looking for a lower or higher C rating?

[Proto]

Re: Battery C Rating

Discharge rate, higher C is better.

[sparrowhawk]

Re: Battery C Rating

C rating multiplied by the mAh is the amperage that the battery can put out, in an ideal world you would know how much amperage your motor needs to pull your spring, and therefore which battery to use

[dave38x]

Re: Battery C Rating

A battery that can delivery 30A sustained is a good basis for a well performing gun

[Proto]

Re: Battery C Rating

C rating multiplied by the mAh is the amperage that the battery can put out

I'm not sure that's quite right, as by your calculations, a 30C 3000mAh battery would output 90,000 Amperes, easily enough to run a drag car on

[bovinedog]

Re: Battery C Rating

90000 mA, or 90 A.


Sent from my iPad using Tapatalk

[sparrowhawk]

Re: Battery C Rating

That would be 90 amps

[Logical Airsofter]

Re: Battery C Rating

Thanks for the help.
So I want to find the Amps needed to pull my spring back then find a batery to suit that?

[sparrowhawk]

Re: Battery C Rating

2 quotes from another airsoft forum

"Most guns will draw a peak of 20-30 amps for an instant at start up, then settle down to 10 or so amps continuous. So in most cases you'd want to make sure the battery can supply a minimum ~10A continuous, with a "burst" at a minimum of 30A. If your battery cannot meet these needs, it can over heat and damage itself.


A device will only draw what it needs from a battery, so if you use one that can supply more than enough juice, say 40A, you basically have a "buffer" zone of 10A."


"Higher Amp is better.

Amps is the measurement of power flow. Think of electricity as a fluid. Let's take a river and a stream and the flow of water as an example.

Now, let's think of our airsoft guns as a city of people. When we fire our guns, the electical circuit in our guns draws current from the battery in order to overcome electrical and mechanical resistence. So to go back to the example, the use of water by the city's citizens represents the about of water current used.

If a city is pulling water out of a stream, the lower capacity of the stream may not be able to keep up with the required flow of water that the citizens need to drink and wash, while a river provides more water current and can sustain a larger population.

In a battery, discharge rates represent the maximum sustainable discharge rate of the battery. For example, with a 10 Amp battery, you could apply a 10Amp load to the battery for the full discharge cycle without damaging the battery. If you have a 30 Amp battery, you can apply a 30Amp load without damage, and so on.

Most airsoft AEG's upgraded to 400fps require about 15-18 Amp of peak current discharge. Stock Marui's require about 8 to 12 Amps on average. Systema PTW's require a minimum of around 24 Amps and can go up to around 35 Amps for the Super MAX.

The downside to this is that it's never easy to look at a gun and always precisely estimate how much current it will draw. Amp meter's capable of testing airsoft current draws are prohibitively expensive (usually well over $1000 dollars or more). The easiest way to determine your Amp draw is by using fuses rated at different currents. You could start out with a 10 Amp fuse, and see if it blows quickly, and then increase the fuse Amp rated until you find one that allows the gun to operate normally without burning out or overburdening the fuse.

With Ni-Cad and Ni-MH batteries, sticking with the 30Amp rated batteries is always best. But with LiPo's you need to be more careful. LiPo's generally have a C rating, and there is a calculation you need to apply to the specs on the battery to determine what the peak discharge rate is. On top of that, LiPo's usually have a "burst" rate, which is generally a higher discharge rate that is available for a very short burst of current. 10C and 15C LiPo's can easily be overburdened and permanently damaged if they are used in guns that can pull over 10C or 15C of current. This is why it's so important to determine your electrical current usage before making the jump into LiPo's.

The reason 30 Amps is better is because it allows for more electrical current to be available that the gun is likely to use at any one moment. It's better to have more available current than not enough"

[Sitting Duck]

Re: Battery C Rating

20c min on stock & 25c min on tweaked guns
(15c not really worth it unless you are really pushed for space/options/price)
35c should do most tweaked setup's

Biggest capacity you can fit in there - pay close attention to sizes/dimensions
make up a bit of wood/cardboard or something a tiny smidge over those dimensions and see if it will fit in your gun ok
remember to add on enough room for wires inc balance lead etc.....
battery sizes can vary a tiny bit even if you have the exact same - so always allow a couple of mm's
(unless you wanna struggle changing batteries that get stuck in ya gun)

deans connector is an option for stock guns but a must for tweaked guns
no biggy to fit but solder one wire at a time - a lipo short can kill the battery and crap your pants

you don't say what spring you are pulling - a 15c will be ok for stock but really best to get a bit more oomph if buying new
2 x 1300mah 20c 7.4v lipo would be a good battery for most, as long as they fit ok - so always do your homework
25c is an option for stock guns if you tweak it later with faster/stronger neodym motor etc....
But if going nutz even on 7.4v a mosfet is must for unleashing more power and preventing arcing on contacts

Soz for ott explanation but all depends on where your gun is and where/if you tweak it later on so just mentioning all considerations

[Logical Airsofter]

Re: Battery C Rating

Okay great, I am currently running a stock G&G M4 and I dont like the crane stock- I think they are too bulky and large. So, I wanted soemthing that would fit in the buffer tube!
I will look at the ampage etc and work this all out.

Thanks for the help

Oh and finally are there any brands of battery I should avoid?
And is a Lipo alarm nessesary and what exactly does it do?

[Sitting Duck]

Re: Battery C Rating

Turnigy Vapex Zippy compact - all are good brands

Stock tube will seriously limit your capacity and choices tbh
often you may find say a magpul stock will need to be extended aprox 2 or 3 clicks to get in a modest battery
perhaps look into a M4 stubby stock - not adjustable but can fit in bigger cheaper block type lipo's in there very easily

I run 2300mah 25c or 35c 7.4v's in mine, can run 11.1v but don't like to cane my guns too too much
easy battery change without removal of stock end etc.....

alarm - nah not unless you are gonna run the lipo really low, I just change mine the moment I feel the rof dropping too much
plus always change battery at lunchtime - no point getting caught out after lunch in middle of a fight

[Logical Airsofter]

Re: Battery C Rating

Okay, great. Will have a look at all the options! I just cant stand the crane stock style!

Thanks for all the help guys, really appreciate it.