Varying Fire Rate

Xtreme · January 22nd, 2009, 01:39

Wondering if a damaged battery would be causing a varying fire rate.

My motor sometimes doesn't have enough torque to turn the mechbox and sometimes I have never seen my AEG fire so fast. While holding the trigger down you can also hear the fire rate increasing and decreasing.

The battery should be fully charged unless it was damaged.

Thanks in advance.

Shirley · January 22nd, 2009, 02:21

Depends what gun and battery you are using.
Then we can help you on what's slowing down the ROF.
It can be small things like grease to big things like battery.
You need to be specific.

Xtreme · January 22nd, 2009, 09:06

It's a Aftermath MP5, V2 mechbox, with a 1200 mah 8.4V battery.

I have just finished cleaning up the mechbox and re-greased it also. From what I could tell everything was fine in the mechbox and the gears felt much better when I tested them.

The reason I think it is the battery is because I let it overcharge one night after a change in plans.

Crunchmeister · January 22nd, 2009, 10:14

The battery is a possibility. Could also be the motor that's bad. However, the battery is a likely culprit because it was overcharged.

I would suggest that you take that wall-wart charger that came with your gun and promptly toss it in the garbage and buy yourself a proper smart charger that won't overcharge your batteries. It's cheaper to pop $100 up front on a decent charger than having to replace $50 batteries multiple times a year. You can get them at several places online or locally at hobby shops that sell RC cars and accessories.

And also a note on batteries - the stock battery that came with your gun is a Ni-Cad. Those need to be discharged before recharging or they will lose their ability to store a charge.

m102404 · January 22nd, 2009, 10:26

I'm not a battery whiz like some other guys on this forum...but here's my take on it.

Batteries are essentially small cans of chemicals. When there's a draw, the chemicals react to provide electricity. Some cells/chemicals are better at doing this (repeatedly).

Also, "matched" packs are made up of cells that are filtered out of the mass production such that the cells are as similar as possible. If you have a couple of good cells, and a couple of not-so good cells...the performance of the pack is dragged down by the not-so good cells...and the not-so good cells can actually be damaged by the good ones. As I understand it, many batteries should not be discharged below a certain voltage (i.e. when they're "dead" they're not really dead...just too weak to be usable). As a pack runs down...all the cells take a hit and the not-so good ones just can't survive for long being over discharged.

Similarly...when you recharge a battery, you are pumping electricity into the pack to reverse the chemical reaction. The finer the material in the cell...the better it'll perform. Rapid discharging and recharging doesn't allow for the crystals to break down as small as possible (it's never perfect or complete anyways and that's why rechargeable batteries have a limited number of useful cycles).

Different chemical combinations alter the discharge/charge characteristics of a pack.

So...if you're getting varying performance...it might mean that you have a not-so-good battery pack. And with an Aftermath/clone rifle...it's a good bet that they company didn't go out of their way to provide a "matched" cell battery pack in their super discount toy.

That leads us right back to what's been said over and over on this forum.
1. Buy a good battery (Intellect, G&P, Sanyo)
2. Buy a good smart charger (peak detection, auto shutoff, trickle charge, varying amperage, etc...)
3. (perhaps not totally relavant, but still a good point) Large cell batteries rule. They last all day and even as they are reused over and over, they still "dump" enough power for an all day skirmish/game. Good quality mini batteries might work really well when they're brand new...but after a season or so of heavy gaming...you'll be carrying around more than one battery to swap out during the day.

Other reasons that you might be getting varying performance, noticeable by the ROF, is that your motor is flaky. Again...discount rifle...discount parts.

It's unlikely that your wiring is bad (i.e. shorting/broken)...but it's possible that poor wiring is limiting the power getting to the motor...taxing the performance of the battery and motor to the point where it's noticeable.

Anyways...start with getting a good battery (the Kraken stock is "short" so regular large airsoft batteries may not fit...sorry) and a good charger.

****Again...I'm not a battery guru...there's a lot of good battery FAQs on this site. Find them...they have tons of well written information in them****

Best of luck,

Tys

kalnaren · January 22nd, 2009, 10:35

Another thing nobody mentioned yet is the electrical connections in the gun. Small Tamiya connectors have a rather high resistance, and if the gun isn't wired well it can lead to performance issues. I encountered this problem on my CA36 before I did a partial rewire. Every now and then the ROF would decline quite a bit even on a fully charged battery.

Crunchmeister · January 22nd, 2009, 10:40

That's a valid point, but in this case, his problem seems more extreme than what a small Tamiya connector could cause. He varies from a great rof to barely being able to turn over the gearbox. That sounds more like a battery issue than a connector. But yes, you're definitely correct about the connector that can be a potential point of voltage drop.

His problem seems identical to one I had with my first AEG - a Double Eagle AK47. I also had overcharged the battery, and had this same issue. Once I ditched the wall charger and used a better battery, the gun worked fine.

Xtreme · January 22nd, 2009, 10:54

I'm going to be giving my friends battery a try later today. Same gun and battery as mine.

m102404 the info you gave is pretty spot on, I'm study Electronic Engineering at the moment so it was understandable.

I did notice that one cell was getting hotter than the rest. If that cell did break down I guess it could be resisting the current I'm not to sure about that though.

The wiring and connector looked very clean also.

The MP5 battery is in the stock... there is quite a bit of room in there for a bigger battery than the one I have, just has to be packaged right.

kalnaren · January 22nd, 2009, 10:58

If you're still using the battery that came from the gun, you might want to consider investing $70 in a new high quality battery and a decent charger.

m102404 · January 22nd, 2009, 10:58

Well screw me blue...why didn't you explain it then?!?! LOL...

Sorry I thought you said Kraken...missed the Broxa part.

Xtreme · January 22nd, 2009, 11:52

Quote:

Originally Posted by m102404

Well screw me blue...why didn't you explain it then?!?! LOL...

Sorry I thought you said Kraken...missed the Broxa part.

lol, you did a good job and it was a good read

I said MP5 not Broxa, some people get confused if I say Broxa

theshaneler · January 22nd, 2009, 12:03

http://www.cheapbatterypacks.com/mai...r=24&model=218

bam! i get these batteries, cheap in price yet still good quality!

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January 22nd, 2009, 01:39	#1
Xtreme Trader rating Join Date: Dec 2008 Location: Lorette, MB	Varying Fire Rate Wondering if a damaged battery would be causing a varying fire rate. My motor sometimes doesn't have enough torque to turn the mechbox and sometimes I have never seen my AEG fire so fast. While holding the trigger down you can also hear the fire rate increasing and decreasing. The battery should be fully charged unless it was damaged. Thanks in advance.

January 22nd, 2009, 02:21	#2
Shirley A-56 aka Mr.Hitman Trader rating Join Date: Nov 2007 Location: Toronto, ON	Depends what gun and battery you are using. Then we can help you on what's slowing down the ROF. It can be small things like grease to big things like battery. You need to be specific. __________________ CANADIAN AIRSOFT PRACTICAL SHOOTING (CAPS) CAPS DIRECTOR # 0047

January 22nd, 2009, 10:14	#4
Crunchmeister Trader rating Join Date: Nov 2007 Location: In your bedroom going though your underwear drawer	The battery is a possibility. Could also be the motor that's bad. However, the battery is a likely culprit because it was overcharged. I would suggest that you take that wall-wart charger that came with your gun and promptly toss it in the garbage and buy yourself a proper smart charger that won't overcharge your batteries. It's cheaper to pop $100 up front on a decent charger than having to replace $50 batteries multiple times a year. You can get them at several places online or locally at hobby shops that sell RC cars and accessories. And also a note on batteries - the stock battery that came with your gun is a Ni-Cad. Those need to be discharged before recharging or they will lose their ability to store a charge. __________________

January 22nd, 2009, 09:06	#3
Xtreme Trader rating Join Date: Dec 2008 Location: Lorette, MB	It's a Aftermath MP5, V2 mechbox, with a 1200 mah 8.4V battery. I have just finished cleaning up the mechbox and re-greased it also. From what I could tell everything was fine in the mechbox and the gears felt much better when I tested them. The reason I think it is the battery is because I let it overcharge one night after a change in plans.

January 22nd, 2009, 10:26	#5
m102404 Tys Trader rating Join Date: Apr 2006 Location: Toronto	I'm not a battery whiz like some other guys on this forum...but here's my take on it. Batteries are essentially small cans of chemicals. When there's a draw, the chemicals react to provide electricity. Some cells/chemicals are better at doing this (repeatedly). Also, "matched" packs are made up of cells that are filtered out of the mass production such that the cells are as similar as possible. If you have a couple of good cells, and a couple of not-so good cells...the performance of the pack is dragged down by the not-so good cells...and the not-so good cells can actually be damaged by the good ones. As I understand it, many batteries should not be discharged below a certain voltage (i.e. when they're "dead" they're not really dead...just too weak to be usable). As a pack runs down...all the cells take a hit and the not-so good ones just can't survive for long being over discharged. Similarly...when you recharge a battery, you are pumping electricity into the pack to reverse the chemical reaction. The finer the material in the cell...the better it'll perform. Rapid discharging and recharging doesn't allow for the crystals to break down as small as possible (it's never perfect or complete anyways and that's why rechargeable batteries have a limited number of useful cycles). Different chemical combinations alter the discharge/charge characteristics of a pack. So...if you're getting varying performance...it might mean that you have a not-so-good battery pack. And with an Aftermath/clone rifle...it's a good bet that they company didn't go out of their way to provide a "matched" cell battery pack in their super discount toy. That leads us right back to what's been said over and over on this forum. 1. Buy a good battery (Intellect, G&P, Sanyo) 2. Buy a good smart charger (peak detection, auto shutoff, trickle charge, varying amperage, etc...) 3. (perhaps not totally relavant, but still a good point) Large cell batteries rule. They last all day and even as they are reused over and over, they still "dump" enough power for an all day skirmish/game. Good quality mini batteries might work really well when they're brand new...but after a season or so of heavy gaming...you'll be carrying around more than one battery to swap out during the day. Other reasons that you might be getting varying performance, noticeable by the ROF, is that your motor is flaky. Again...discount rifle...discount parts. It's unlikely that your wiring is bad (i.e. shorting/broken)...but it's possible that poor wiring is limiting the power getting to the motor...taxing the performance of the battery and motor to the point where it's noticeable. Anyways...start with getting a good battery (the Kraken stock is "short" so regular large airsoft batteries may not fit...sorry) and a good charger. **Again...I'm not a battery guru...there's a lot of good battery FAQs on this site. Find them...they have tons of well written information in them** Best of luck, Tys

January 22nd, 2009, 10:40	#7
Crunchmeister Trader rating Join Date: Nov 2007 Location: In your bedroom going though your underwear drawer	That's a valid point, but in this case, his problem seems more extreme than what a small Tamiya connector could cause. He varies from a great rof to barely being able to turn over the gearbox. That sounds more like a battery issue than a connector. But yes, you're definitely correct about the connector that can be a potential point of voltage drop. His problem seems identical to one I had with my first AEG - a Double Eagle AK47. I also had overcharged the battery, and had this same issue. Once I ditched the wall charger and used a better battery, the gun worked fine. __________________

January 22nd, 2009, 10:54	#8
Xtreme Trader rating Join Date: Dec 2008 Location: Lorette, MB	I'm going to be giving my friends battery a try later today. Same gun and battery as mine. m102404 the info you gave is pretty spot on, I'm study Electronic Engineering at the moment so it was understandable. I did notice that one cell was getting hotter than the rest. If that cell did break down I guess it could be resisting the current I'm not to sure about that though. The wiring and connector looked very clean also. The MP5 battery is in the stock... there is quite a bit of room in there for a bigger battery than the one I have, just has to be packaged right. Last edited by Xtreme; January 22nd, 2009 at 10:56..

January 22nd, 2009, 10:58	#10
m102404 Tys Trader rating Join Date: Apr 2006 Location: Toronto	Well screw me blue...why didn't you explain it then?!?! LOL... Sorry I thought you said Kraken...missed the Broxa part.

Varying Fire Rate

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