Can AEP's take a Li-Poly battery?

[yoyit2]

wow.. old thread. i was thinking this up a while ago.. and there is alot of assumption here but just hear me out.

ok, so the stock battery for the TM 18c AEP is 7.2v 200mah, 8 cells. if you break it down, that should be 2 banks of 4 cells. (4 cells in series make one bank, each bank is then put into parallel). basically 4 cells in series would give you 7.2v 100mah, but them in parallel and you get 200mah.

so... if you take 7.2v / 4cells =1.8v per cell. which is 1.8v 100mah per cell.

if you take all 8 cells in the battery pack, and rewire 5 of them into series, (making 9V) and use ther remaining 3 cells as fillers (to keep the battery packs physical shape/size the same) your battery will now be a 9V 100mah.


taking this same principal to a 7.2v 500mah battery (like the "upgraded" batteries you can buy ~$20.00) you can make it into a 9V 250mah battery

correct me if im wrong, but i was gunna give this a try in my gun =P

[ThunderCactus]

7.2v at 200mah?
Going to a 7.4v 15C LiPo might give you a ridiculously high ROF in an AEP...

Remember the energy efficiency of LiPo's is in it's ability to supply 100% of the amperage required by the motor.
So with a 200mah NiMH your probably getting really low drain, less than a 7.2v 1500mah battery.
A 7.4v 15C LiPo is more or less equivalent to a 9.6v 1500mah battery. And unlike NiMH cells, a LiPo's performance will not decrease as you make the pack physically smaller (decrease in surface area lowers the drain in NiMH cells).
So as long as your supplying the required current, a 7.4v 500mah battery would still have a similar output of a 9.6v 1500mah battery.

Also keep in mind, if you can't supply the proper amount of current with the smaller size of LiPo (10C at 500mah is only 5A), there's a good chance you'll burn the battery.
And ontop of that, since the battery is so small, there's a greater chance of you over-discharging it. So you'll also need to make room for a PCB...

I'd recommend sticking to NiMH for AEP's

[Amos]

I'm using 7.4 20C 500MAH LIPO in my Scorpion and it's not having any issues aside from the PDI spring I put in being too strong.

[yoyit2]

wait a second... the mah is Milliamp Hours ...which is storage capacity. not actual Current output!

just throwing out random numbers here, to make a hypothetical battery.. to prove my point.

1cell = 1.8V 2000mah (2ah) with 5A (a=current)

if you take 4 cells and put them in parallel you get a bank producing 1.8V 20A 8ah

now if your motor requires 1.8V 4A, this doesnt mean having a 20A output on a battery is gunna overload it. the motor will still only DRAW 4A from the battery, not 20A

the point im getting at is:

having more Amps (current) wont change the ROF, BUT will increase the speed of the initial ROF (aka, first 2-3 shots/ or semi auto)

WHY??

cuz of in-rush current - which is a higher draw when the motor first starts. yes the motor is rated at 4A but thats FLA (full load Amperage) which is what the motor will draw once it is at a steady speed. (full auto) that being said the In-rush current might daw, lets say 5-6A its kinda like your fuel efficiency of your car, while your driving on the free way, or starting from a stop.

so... a battery with 1.8V 4A 2ah will be able to support the said hypothetical motor fine, at FLA... but its initial In-rush current while draw more then the battery can output. which means semi auto will be sluggish, and full auto will be like: pop... pop.. pop,pop,pop,pop (exaggerated).

were as a battery with 1.8V 6+A (mah doesnt really matter at this point) will be able to handle both In-rush current, and FLA. which means semi auto will take the same time to wind the spring back, and fire as on full auto (one full cycle). full auto will sound like this: pop,pop,pop,pop

so as far as i understand, weather lipo,nicad,nimh.. etc. as long as the Amps can support the In-rush current/FLA then its all down to the Volts to effect ROF. MAH determines how long it can support it. (like a laptop battery rated in Whrs, a 56Wh will last longer then a 32Wh battery, but its performance will be the same.)

[Kos-Mos]

Originally Posted by yoyit2

wait a second... the mah is Milliamp Hours ...which is storage capacity. not actual Current output!

just throwing out random numbers here, to make a hypothetical battery.. to prove my point.

1cell = 1.8V 2000mah (2ah) with 5A (a=current)

if you take 4 cells and put them in parallel you get a bank producing 1.8V 20A 8ah

now if your motor requires 1.8V 4A, this doesnt mean having a 20A output on a battery is gunna overload it. the motor will still only DRAW 4A from the battery, not 20A

the point im getting at is:

having more Amps (current) wont change the ROF, BUT will increase the speed of the initial ROF (aka, first 2-3 shots/ or semi auto)

WHY??

cuz of in-rush current - which is a higher draw when the motor first starts. yes the motor is rated at 4A but thats FLA (full load Amperage) which is what the motor will draw once it is at a steady speed. (full auto) that being said the In-rush current might daw, lets say 5-6A its kinda like your fuel efficiency of your car, while your driving on the free way, or starting from a stop.

so... a battery with 1.8V 4A 2ah will be able to support the said hypothetical motor fine, at FLA... but its initial In-rush current while draw more then the battery can output. which means semi auto will be sluggish, and full auto will be like: pop... pop.. pop,pop,pop,pop (exaggerated).

were as a battery with 1.8V 6+A (mah doesnt really matter at this point) will be able to handle both In-rush current, and FLA. which means semi auto will take the same time to wind the spring back, and fire as on full auto (one full cycle). full auto will sound like this: pop,pop,pop,pop

so as far as i understand, weather lipo,nicad,nimh.. etc. as long as the Amps can support the In-rush current/FLA then its all down to the Volts to effect ROF. MAH determines how long it can support it. (like a laptop battery rated in Whrs, a 56Wh will last longer then a 32Wh battery, but its performance will be the same.)

Laptop analogy does not work. Laptop batteries are "enlarged" by adding extra cells, thus rising the voltage. It will then be lowered by the internal DC-DC switching PSU that will drive the system.

If you want to know if X battery will drive Y gun, you have to take it a a whole. The maximum current drain in a motor outside a mechbox will be when you stall the motor (fully lock the shaft). That happens for a fraction of a second in an airsoft gun, unless you are really having a huge spring in there.

To apropriately find what the lower limit for current rate of your battery will be, you need an expensive logger that is hooked to the system, and reads current, resistance and voltage over time. Then you can find what is the peak and all.

The more down to earth solution is to learn from mistakes others did.


Short answer: You can run an AEP on a E-Flight Blade CX battery no problem.

[Cheesevillage]

Originally Posted by Amos

I'm using 7.4 20C 500MAH LIPO in my Scorpion and it's not having any issues aside from the PDI spring I put in being too strong.

I'd be interested to see a thread detailing what you've done to your scorpion and how it turned out WRT accuracy/battery life/range/price/ parts longevity/ etc

[yoyit2]

really sorry guys, every time i click back, it re-logs me in, and reposts my post. SORRY

[Kos-Mos]

You can delete your old post by going into advance editing.

[mr_nuts31]

I have one and the batteries are located inside a flashlight attached underneath. ill show you the pics later of it