Efficiency test, what setup is best??

[ThunderCactus]

This has been bugging me for a while, and I want to find out which method is actually better for battery efficiency.
I've kept track of the battery efficiency of all my guns, unfortunately none of them before the 249 had any good motors so the data from those is all useless lol

7.4v lipo, high speed gears, neo magnet motor
1200-1500rpm no problem
16:1 and apparently even 18:1 standard ratio can be used with a fast enough motor
Figures were pulled from 350fps guns, but are also possible at 400fps

Or

11.1v lipo, high torque gears, ferrous magnet motor
1200-1500rpm no problem depending on the armature windings
Using 26.43:1 gears and an eagle force EF1300 I'm getting 1400rpm at 380fps


With the high torque approach, you're using high amperage. The increased torque puts more strain on starting, and potentially runs hotter since the amperage is way up.

With the low torque approach, the motor has less trouble starting, and because there's less resistance in turning and it's using ferrous magnets, it uses much less amperage. Downside is the arcing from 11.1v can dirty up the comm fairly quickly in lesser quality motors (took 3yrs of heavy use to dirty the comm on the EF1300).

Basically I want to see which uses lower wattage. Having the actual wattage would be great, but I'll settle for a BB/mah figure lol

Obviously you're going to get much worse efficiency using semi-auto, so please state how you're shooting, and be fairly specific about the build but not anal. I assume if you care about your battery efficiency the shimming is already perfect =p
If you know, please specify if the gears are heavy or light, momentum makes a big difference in starting a gear train and maintaining full auto.


V2 mechbox
380fps (prommy ms110)
heavy prometheus triple torque (26.43:1) gears
kanzen ceramic bearings
eagle force EF1300 ferrous magnet motor
programmable mosfet with AB on
16ga high efficiency silver coated copper wire with two sets of deans (one in box mag, one on gun)
11.1v 20C 4900mah lipo
*lipo also powers the tiny box mag motor
15-30rnd burst, full auto only
averaging at 7BB/mah

[ThunderCactus]

REALLY???
NOBODY keeps track of their battery efficiency???

[Ricochet]

Ughhhhh.....the big one?

[Danke]

I honestly think you should just pick the setup you want and buy it; then afterwards ask us about it in super vague "what iffy" terms and say do you suppose a lot and say isn't it possible.

That sort of thing we're really good at answering.

[Kos-Mos]

Originally Posted by ThunderCactus

REALLY???
NOBODY keeps track of their battery efficiency???

Yes.

My battery have been "fully" charged since 2013.

I run gaz guns ever since.

But on a more serious note, no.
Batteries are good enough now that it goes through a whole day without issue, even with Neo-high-torque motor, 18:1 standard gears and 400fps (397) spring.

At that point, nothing gets warn enough to be worrying, and there is no arcing since I run a basic FET (and it takes 40V and 240A).

[Stealth]

This thread can be easily answered with a wattmeter and about 30 seconds.

[SuperHog]

Hey ThunderCactus,

Try this. This is the one I use on airsoft, and all my RC stuff. Saves on guess work and best way to determine if your battery is giving out the juice your devices need. Mest method to find weak batteries and ampere killing motors.

http://hobbyking.com/hobbyking/store...up_Ver_2_.html

[ThunderCactus]

If I had a high amperage setup at my disposal, I would already have my answer without the need for a watt meter lol

The watt meter is helpful, but entirely useless without a gun to compare mine to

[spaceman13]

The 7.4v setup is 20% cooler.

[DipTwit]

ThunderCactus, I have the same wattmeter, and several guns, but I'm not convinced that any of them are 'high amperage' enough to tell you what you want. Also, I suspect that getting an accurate reading using only 15-30 shots might be dubious.

So first, what were your peak amps & watts for a single shot, and short FA burst, just so I can compare to see if any of my guns would be helpful?

Second, would it be feasible to leave the wattmeter hooked up during a game so you can get a good mAh reading over, say, a thousand rounds? I've considered doing this, but wouldn't bother without the data being useful to someone.

[targetGspot]

I've never worried about battery efficiency, I care more about the gun holding up. Batteries are cheap and easy enough to change. I've only once or twice had a battery die mid game, I change mid day if I think I've fired enough to run one down. As long as it's powerful enough to run the motor and not too much for the gun I'm using...

[DipTwit]

Haha yeah it's one of those things that nags quietly at the back of your brain until one day you just really want to know, just how big a battery do I need for Risky Sun???

[ThunderCactus]

Originally Posted by spaceman13

The 7.4v setup is 20% cooler.

5pts for the reference lol

It doesn't matter when you test your gun, as long as you do it with a full battery.
The wattage will change as your voltage drops in the battery.
If the amp draw of your motor changes noticeably during the course of a few hundred rounds, something is horribly the hell wrong with your gun.
So for this test, you only need to compare a few shots in semi, and see what it reads consistently over a full auto burst.

I might as well order the watt meter now since nobody else in this country keeps track of how many mags they get out of a battery lol

[DipTwit]

Haha really I'm not surprised.

My comment about the rounds is that it's hard to get several sig digs of accuracy over 15 rounds since that's like, what, maybe 2 mAh? Even with a watt meter you won't get 2 decimal places with that low a number.

But yeah you could get an idea, now I have to see what I get on each gun <sheesh> cuz I'm curious.

[Kos-Mos]

Originally Posted by ThunderCactus

5pts for the reference lol

It doesn't matter when you test your gun, as long as you do it with a full battery.
The wattage will change as your voltage drops in the battery.
If the amp draw of your motor changes noticeably during the course of a few hundred rounds, something is horribly the hell wrong with your gun.
So for this test, you only need to compare a few shots in semi, and see what it reads consistently over a full auto burst.

I might as well order the watt meter now since nobody else in this country keeps track of how many mags they get out of a battery lol

What? No...

Voltage will drop, current will rise to provide the same power (watts) to the motor/system. Up to the point where the battery can't provide enough and then the power will drop.