3 different battery test

[Scarecrow]

Originally Posted by ILLusion

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!

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.

[schmuck]

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..

[Giuseppe]

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.

[ILLusion]

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:

Originally Posted by ILLusion

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?

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.

[Giuseppe]

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?

[LUTNIT]

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:

[ringsted]

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

[arman]

Originally Posted by Scarecrow

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?

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

[ThunderCactus]

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.

[ancorp]

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

[MADDOG]

Originally Posted by ancorp

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.

[ancorp]

As I expected, thanks.