3 different battery test
 

I am not the first to do this, but you can't have too many examples

http://i33.photobucket.com/albums/d9...atterytest.jpg

Volts are not everthing when it comes to batteries. Another case in point.
Gun has standard gears, classic army super torque motor, and a PDI 150%


The order in the movie.

7.2 3300 nimh
8.4 1700 nicd
9.6 2000 nicd

The nicds were discharged and charged twice to regain full mah. All were at room temperture.

http://i33.photobucket.com/albums/d9...tterymovie.jpg
And yes I was watching in the footsteps of binladin

So what was your personal conclusion of this test?

My main goal was to prove you can use 7.2 volts batteries in an upgraded gun.

1. You could use all of them for gaming.
2. You can use a 7.2 volt battery in an upgraded gun.
3. Rate of fire change was not that big, I am guessing maybe 2 bb/s for the 8.4v and maybe 3 bb/s for the 9.6.

Save your money and instead of buying those extra two cells just go for more mah.

CDN_Stalker has been telling me the same thing in a couple conversations weve had on msn. The battery with the higher mah will have a higher rate of fire usually, regardless of voltage. A 9.6V 3300mAh will still have a higher rate of fire than an 8.4V 3300mAh but not by that much (noticable but not a drastic increase) and 8.4V 3300mAh will have a higher rate of fire than a 9.6V sub-3000mAh. It all seems to make sense, gotta go get me a 7.2V 4300mAh to test out now...

But when you consider the price of batteries the extra two cells to get it up to 9.6V compared to 7.2V is maybe $85 instead of $70 (using IB 4200mAh SC NiMH cells) and when you consider the price of airsoft in general that is a very small difference, true the gain in rate of fire wouldnt be too large but for only $15, I dont mind.

I guess my point is, why do people use batteries that aernt the max mAh for the size? I see people running around with $50 1700mAh large batteries and wonder why they didnt spend the extra $20 to get a 4200mAh battery, it just doesnt make sense to me. I only have 3300mAh batteries instead of 4200 or 4300mAh because 3300 was the max mAh I could find when I was shopping around, only later did my friend show me some R/C car sites where I can get up to 4300mAh batteries. I know some people prefer NiCd's to NiMH and that I respect but it isnt always the case, people just seem to go cheap on batteries. My P90 came with a 1700mAh J-battery when I know the same size cell is avaliable in 2500mAh to give a higher rate of fire, and I know there are many people that use 2-3 600mAh mini's in their guns instead of 1400mAh minis that cost only a fraction more.

Are the larger rated mini cells relatively new? They didn't appear to be readily available a couple of years ago when I bought my batteries. Maybe time for me to start spec-ing replacements anyway.

I saw a 1400mah NiMH minis, 8.4V. It had a very good firing rate, a very small.

They've been around for a while now, but they are Ni-MH. You'll need a supporting charger.

Personally, I'm still not a fan of Ni-MH, especially if you plan to play in any environment that is 5 degrees or colder.

I was consider getting 7.2v li-poly. I wonder if similiar results would apply. I bet the 7.2v at full charge would produce 8 or more volts. Hmmmm....

lipo is 7.4 :)

NiCd's are better in the cold? This subject has never come up before in anything that I've read, I have no experience with it, and my R/C racing friend doesnt exactly race in the snow...

Are the chemicals in NiMH batteries retarded in the cold so their output drops or something? I always chose NiMH because the mAh capacity is almost always a lot larger and you dont have to worry about memory effect (even though I know its still there to a small degree and NiCd's can often be recovered from the memory effect.)

Well, in my experience, both NiMH and NiCAD suck in the cold, NiCAD is just marginally better. Plastic hopups are even worse in the cold as they tend to shatter. Generally rule of thumb is when it is cold, find a way to keep the gun warm, or you risk breaking your gun. I used to winter game, but, 3 or 4 hopups later, I don't anymore.

There is no question that NiMH is not as good a performer for pushing a battery in the same voltage and amperage as NiCAD however, when you have space limitations and you can get a 1100mah NiMH in the same space as a 600mah NiCAD, the NiMH is (in my experience) the better option. As you get larger, I think this changes. If you have the space to spare, get the NiCAD.

P.S. Maybe someone in the know can answer this one, but my assumption was the voltage basically overcomes the friction of turning the motor and thus all the gears, and the tighter the setup, the more voltage is consumed in that push over friction. So if you have a good shim job, its easier on the motor and the battery and the battery will last longer. Bad shim job, more friction, shorter bat life. And in all this mah just dictates rate of fire... is this a correct characterization?

Yeah, thats what I was told by a couple different people, upgraded spring = shorter battery life because more force is required from the motor, same thing if theres extra friction.

Rate of fire is determined by voltage and current. mAh stands for mili-amp hours, how I understood this is if there is a 1000mAh charge that means the battery will last for 1 hour at a draw of 1000miliamps or 1000 hours at a draw of 1miliamp. Rate of fire is determined by both voltage and avaliable current, higher voltage = faster motor cycle and more current = faster motor cycle. I wont go into details as I'm sure I will get them wrong but that is essentially (I think...) what CDN_Stalker told me. Think of a taser, they have incredibly high voltage and next to no current, thats why they aernt nearly as fatal as jabbing a fork into a wall socket. The voltage is the amount of electricity but the current is how fast its moving (or maybe I got that backwards...)

I made a video to this effect several months ago to quell the naysayers on Arnie's Airsoft that a 7.2V wouldn't even turn over a stock gun. Not only did it work just fine, an 8.4V gave only 1 round per second extra speed over the 7.2V.

In fact, I use an Intellect 7.2V 4200 mAh pack in my M249 with a 400 fps spring, no other mods. I get probably close to 900 RPM on that battery. Going back down to a stock spring yields an even faster ROF that borders on wasteful.

The only 8.4V I own is an Intellect 1400 mAh mini for my MP5.

That is correct though it's amps you're consuming, not voltage. The more resistance you put on moving parts the harder the motor will have to turn, and thus draw more current. Bear in mind that current (amps) are not really something that is 'given' by the battery, it's something that is 'taken' by the device being powered. The harder a device has to work, the greater it's amp draw will be. If the battery cannot provide the requisite amount of current the device will not be functioning at it's full capacity. That's why the mAh rating is important, because not only will the battery have the capacity to power a high drain device but will also have a low internal resistance to provide those heavy currents.

Like Scarecrow said, both chemical types begin to degrade in performance as the pack gets colder. However, you will notice the retardation sooner with Ni-MH types (around 5-10 degrees) whereas Ni-Cd can go a bit colder before you notice it (around 0 degrees). At -20, you might as well just leave your Ni-MH packs at home, unless you like playing with a ROF of 0.8 shots per second. ... and if your idea of a shoot-em-up day is being able to barely shoot off 3 lowcaps. I swapped to an external 8.4v 2400mAh Sanyo NiCd pack afterwards and ROF picked up, was still a bit slow but it still held up fairly well and lasted me the rest of the day.
(those numbers are based on my experience with an 8.4v GP cell 2500mAh A-cell pack in my P90.)



Here is another way of looking at the issue:

Heavy upgrades also add stress to the motor - this stress also gets translated in to the battery. Any extra stress to the motor adds stress to the battery. Stresses can come from binding pistons, heavy springs, poor shimming jobs, high speed gears, etc etc. Higher torque gears will ease a lot of pressure off the motor and battery if running heavier upgrades. Personally, I always upgrade at least one torque level above standard ratio for any springs above 360fps.

Generally speaking, the main controller of rate of fire is voltage and current and the controller of how long you can shoot for is the capacity of the cell.
Larger cells (such as sub-C versus 2/3A [mini] cells) and even larger capacity similar cells (such as 4200mAh versus 2700mAh sub-C cells) have lower internal resistance within the cell. Basic physics tells us the relationship between V (voltage), I (current) and R (resistance). As resistance goes down, current is affected (since voltage stays the same) - and is why we notice a higher rate of fire with very large packs compared to smaller packs, even though voltage ratings are the same.
Even comparing a Sub-C 1700mAh pack to an A-cell 1700mAh pack, you will notice the sub-C pack has a higher ROF and seems to crank a spring with more gusto.

There are other factors that affect the rate of fire and how long the cell will last. For example, back to the 1700mAh Sub-C versus A-cell comparison again - a sub-C pack lasts longer than the A-cell. Why? Back to the internal resistance issue. The extra energy contained by the added resistance has to be released somehow. In the case of this chemical reaction, the extra energy is released as heat - wasted energy.
In a world of perfect atmospheric conditions, perfect cell production with 0% contamination and perfect cell mixtures and equality in a pack; yes... the rule of thumb of a 1000mAh charge lasting 1 hour at a draw of 1000mA or 1000 hours at a draw of 1mA. But that can only be used as a very general rule of thumb.



ALL of these reasons are why it's never recommended to jump to a high mAh pack when you have a low powered (stock) gun. I've seen pistons ripped to shreds in less than 10,000 rounds with 8.4v 2400mAh NiCad packs. Tokyo Marui's actual recommended pack for stock guns in sub-C form are 1300mAh!
Experienced tuners and shops do NOT recommend any higher than 1700mAh large packs for stock guns for this very reason! 4000+mAh packs lead to quick deaths for stock guns.

Higher capacity is NOT always better because in what I've just written above, higher capacity also means much more than just how long you can shoot for!

One way to balance it out if you MUST go to very high capacities on low powered guns is to drop the voltage level, which as the test in this thread proves, is still very effective for airsoft, even when running at 7.2V.
Depending on your size constraints, the stress to your motor and the size of your packs, your gun may be able to run at 6 volts? Who wants to give it a try? :D

Glad you said it, its one of the reasons I don't sell bats above 1700mah. I've rarely ever seen a need to run a gun that hard. All you end up with is heat and wear. If you need something over 1700mah you've either zooped the gun up the whazoo or you've used superglue for shimlube.

i use a an 8.4V 2400mAh Sub-C battery on my stock CA M15, is it ok if i continue using it? so far it hasn't caused a problem after about 4000+ rounds..

I still don't understand why using a battery with large mAh is bad? Everyone I talk to say that the larger the mAh the longer the available usage. I have never heard anyone say that the greater the mAh the harder it is on the motor. The way I understand it is that the greater the mAh the more power is stored in the battery. That power is always outputed at the same level regardless of the mAh, be it 1700mAh, 2200mAh, or 4400mAh.

It's bad because the rate of fire is too high for the stock spring to keep the piston up with the gears. The result of high ROF setups too high for the gun is that the gears return to wind the piston before the piston gets back in to position and you end up grinding the teeth together before the racks are ready to cycle again.

Nobody ever said that higher mAh rated batteries are hard on the motor. It's only hard on your gears and piston teeth if your spring is low powered!

Here, let me post it again, in case you missed it the first time around:


If you don't understand the theoretical concept based on my explanations above, here is a perfect test:

Use a fully charged 8.4v 600mAh mini battery to fire a burst through a gun. Any gun. Stock or upgraded.

Now use a fully charged 8.4v large capacity battery pack... 2400mAh NiCad, 4600mAh NiMH, whatever. Doesn't matter. Either one will prove the theory. Fire a burst through the same gun with that pack.

Notice the difference in ROF? Despite the packs voltage rating being the same at 8.4volts, the larger pack has a markedly higher ROF, especially when the gun is fully upgraded. This is due to the lower internal resistance of the cells.

Ohm's law (V=IR) states that if voltage stays the same, and resistance goes down, then applied current goes up.

The result? Higher Rate of Fire with higher capacities due to the nature of differences in different capacity cells.

Ok, I see what you are saying now. I guess you really have to know how the airsoft guns functions to see why a greater rate of fire would damage the gears, besides greater wear and tear. I don't know much about how these guns function yet to know that the teeth would grind, etc. So what strength of spring would warrant using a 4200mAh??? How about using a 150 PDI Spring on an TM AK47?

Its often recommended not to use a PDI spring as they are old technology, the non-linear springs made by prometheus, systema, hurricane, etc. are all much better. When I had a gun with a Prometheus M110 it shot 368-370fps, my P90 with a PDI 170% shoots 390-401fps, a much larger variance. The spring I prefer and the one most recommended by many gun doctors and experienced games as far as I know is a Prometheus M110 or M120, the M120 will bring your gun over the 400fps limit on most fields if there are other upgrade in it (tightbore, piston head, bearing spring guide, etc.) so its usually safe to stick with an M110.

I am in no way claiming any exceptional experience, this is just drawn from my limited experience and what several heavily experienced members of these boards have told me, as always Illusion is the one to talk to for details as his wealth of knowledge scares me at times :neutral:

well if you want to see a real battery comparison go here

http://ffw.pgup.dk/anmeldelser/Gunzo...ne-batteri.htm

it is one of my team mates that made it
there is a line up of 4 different 9,6 batteris, the ROF is measured with audacity which is the real way of doint things.

the small GP 1100 celle is not much worse than a large 9,6 3000 battery.

a stock gun can run no problem on a 8,4 4300 mah battery, at least in denmark they can. guns other than marui use a 9,6 4300 battery no problem from stock.

some even use 12 v 4200 mah batteries in M100 tuned AEG's 330 fps. which run from 28-32 RPS and they still dont have severe breakdowns.

a normalt gun in denmark can run on 10,8 with a M120 spring and still be very reliable, we need to change pistons (marui piston) evert 70000 shot or so.

Best regards
Lars Ringsted

i bought a gun from the used section tm g36c. The seller said it was upgradded by the previous owner,the battery fully charged(bbastard charger) fired off half a hi cap.asked the seller what was upgraded? he didnt know said shoots 360 and recomends a 9.6 battery. i bought a 8.4 1200 intelect, charged it up and got more shots but still bout a half a hicap. would a stronger spring do that to a battery? i dont want a higher voltage till i know it wont spit the gears out. so i used the serch feature and found this... i did however buy a promethus shim set, King Arms 1J Spring, King Arms 6mm Oiless Metal Bushing, Guarder Teflon Grease for AEG Gearbox. i dont know what spring is in there so i bought a reg one to test the battery issue... any help please im a doc in training

I use a 7.2v 4200mah intellect in all my upgraded guns with an inaudible difference to using an 8.4v 3600mah battery, so getting very close to the same ROF.
For mini batteries, I find under 350fps they are okay with standard gears, but above 350fps you need torque up gears and maybe a torque up motor. The gears will allow you to use your gun at a higher fps, and the torque up motor seems to use less power to do the same job as the high speed motor.

Wohoo old thread. I noticed noone mentioning the discharge rate (although I have only skimmed through the thread). I have a Tenergy 1500Mah Mini, and an Intellect 1400mah mini as well. The Intellect gives a much higher rate of fire. Both 8.4v. Discharge rate. I believe the Tenergy one only has about 8-10amps?

Anyone have a proper explanation for this?

Cheers,
Alex

Tenergy are low cost batteries with performance to match.
Intellect, Sanyo, GP all have better discharge rates, are more balanced and perform better than no-name batteries.

When it comes to batteries you get what you pay for. I use nothing but Sanyo Nicad and GP NIMH. I had custom 9.6v sub-c batteries made at Total Battery in Barrie and after 2 uses (Charged and discharged properly) would not even crank my upgraded gun. I thought it was the gun itself. Put a 4 year old sanyo on it that had not been charged for over 6 months it fired like a dream. The high quality cells are better matched to reduce resistance and will out live any low end brand.

As I expected, thanks.