Jump to content

Archived

This topic is now archived and is closed to further replies.

infected

Lithium-Polymer (LiPo) Battery Primer

Recommended Posts

Word on the KWA Li-Poly ready guns:

 

They are li-poly ready, but I'd say 7.2v li-poly ready. They still have angle of engagement issues, and a stupid metal tooth piston. So if your piston teeth go, there goes your gears. Metal teeth are the bane of Airsoft. There is no need for them. If something is going to fail in your gun, you want it to be minimal in cost and minimal in collateral damage. So by having the Angle of Engagement off, the teeth can jump or not mesh properly (especially with an 11.1v battery), so you no longer have a 100% gun, and then you have a failure... and again everyone blames the li-poly without realizing that you have a gun that wasn't built to handle the 11.1v.

Share this post


Link to post
Share on other sites
Most of those do not use Lithium Polymer batteries but Lithium-Ion batteries. Big difference.

 

However, technology is actually just starting to use them and implementing them in stuff. Popular products include iPhones and PS3 wireless controllers.

 

Yes there is a difference between Lipo & lith-ion.

 

Lipo is arguably an emerging, or established power source. :rolleyes: Depending on your perspective & willingness to update tecky stuff. :huh: Lith-ion is a bit, er, last year. ;)

 

However, I'm sure you get my point. :)

 

 

Greg

Share this post


Link to post
Share on other sites
Even though I had some problems, I still love lipos. I just think the 11.1v is too strong. I dont want to be replacing gears/pistons once a year, And I dont have the bankroll to make the KWAs internals go from great to indestructable, so a 7.2v lipo is fine.

 

I'm running an 11.1 in my KWA G36 right now, but from the very beginning, i've used a trigger master mosfet to bring the ROF back from 28rps to 21. So far, so good :)

Share this post


Link to post
Share on other sites

FYI, part two of the series is almost done. It's typed up and needs to be proofed and pictures added. It's still looking like Monday for the publish date. I think it's going to be a 3 part series, as I've still got more information to add to it, but I want to keep the articles down to a manageable size, especially with this topic.

Share this post


Link to post
Share on other sites

Give me a shout when it's done, Infected. I can edit your original post and add a link etc.

 

Edit: Also just wanted to say that after seeing your soldering tutorial and reading through this, I've gone out and bought some new solderng kit in a bid to sort the dodgy electrics which I have on some of my rifles / electric magazines. If all goes well, I'm also looking to rewire the RPK gearbox to take a stick lipo so that I can add real steel RPK furniture. All due to you, matey. :)

Share this post


Link to post
Share on other sites
Give me a shout when it's done, Infected. I can edit your original post and add a link etc.

 

Edit: Also just wanted to say that after seeing your soldering tutorial and reading through this, I've gone out and bought some new solderng kit in a bid to sort the dodgy electrics which I have on some of my rifles / electric magazines. If all goes well, I'm also looking to rewire the RPK gearbox to take a stick lipo so that I can add real steel RPK furniture. All due to you, matey. :)

 

 

Awww... shucks... twern't nutten'. :D

 

For real though, thanks for all the kind words guys!

Share this post


Link to post
Share on other sites
ok cheers infected. will be contacting you in a cpl of weeks about a cpl of mosfets! just one quick question would you reccomend using a mosfet in conjunction with a li-pol?

 

I sure would. With that much current able to go through your gun, I recommend (and use myself) a mosfet to increase the life of your trigger switch. My m14 DMR (Semi-auto only), uses a mosfet and I use an 11.1v lipo on it. I also have a mosfet on my M249 which uses a 11.1v lipo too.

Share this post


Link to post
Share on other sites
I sure would. With that much current able to go through your gun, I recommend (and use myself) a mosfet to increase the life of your trigger switch. My m14 DMR (Semi-auto only), uses a mosfet and I use an 11.1v lipo on it. I also have a mosfet on my M249 which uses a 11.1v lipo too.

 

yet again thanks infected! gonna be using an 11.1 in my spr (semi only) so will deffo be installing a mosfet!

Share this post


Link to post
Share on other sites
Word on the KWA Li-Poly ready guns:

 

They are li-poly ready, but I'd say 7.2v li-poly ready. They still have angle of engagement issues, and a stupid metal tooth piston. So if your piston teeth go, there goes your gears. Metal teeth are the bane of Airsoft. There is no need for them. If something is going to fail in your gun, you want it to be minimal in cost and minimal in collateral damage. So by having the Angle of Engagement off, the teeth can jump or not mesh properly (especially with an 11.1v battery), so you no longer have a 100% gun, and then you have a failure... and again everyone blames the li-poly without realizing that you have a gun that wasn't built to handle the 11.1v.

 

Thats EXACTLY what my other post in this thread suggests. Switching to a 7.2v b/c ,my11.1 has started giving me problems. Good thing im not alone in reasoning. Although I did put a metal tooth piston in for use with the 7.2v >_> (Dont kill me)

Share this post


Link to post
Share on other sites

You guys can give me a shout out when there is a nice, big, high quality li-po made for a crane stock. One that will out perform my ELITE4700 12v and fit in the stock with my custom SW-EVO. Then we'll talk.

Share this post


Link to post
Share on other sites
ok can someone please tell me the main difference between li-po & li-ion? sorry if this is a stupid question but i really want to know!

 

Right, where to start. I think I'll keep it simple, 'cos I'm a terrible writer & will tie myself up in knots if I'm not careful. Google is your best friend if you want to know more, but basically:

 

Lith-ion is basically a rechargeable lithium based call, similar to a conventional disposable lithium battery. It's configuration, the way it works, & construction is the same as any other conventional rechargeable cell, but it's 'working materials' allow performance improvement over nimh's etc. For every day users the key features are that (like nicads & nimh's) they can be run flat, are usually cylindrical & contained in a 'solid' structure. They are, due to the run flat & solid casing, seen as 'safer' & preferred for general applications. About 4 years ago (as li-po was just being played with) they were seen as the natural progression from Nimh, the same way Nimh took over from ni-cad. Examples currently include the 'latest generation' (available for about 18months) of rechargeable hand tools & older (3 years +) laptop pc's. They have been used in cell phones are still used in 'larger' mobile phones, such as Nokia's N95.

 

Li-Po (Lithium Polymer) is streets ahead. It is a completely 'new' style power cell & works in a different way to the conventional cylinders. The main feature is, improvement in power to weight performance. Particularly in discharge & charge rates. The key to this is the flat, rectangular construction which allows faster exchange rates. Another feature is their 'burst' feature. Other batteries (particularly nimh) give a relatively slow discharge when first (we are talking milliseconds here) connected & then speed up. So, your first shot in full auto will be relatively slow compared to the following shots. Remember, this is compiled by other factors like inertia, etc. The Lipo is the opposite. It gives its best performance for the first few seconds, it's 'burst' & then settles down. This helps in most 'motorized' applications. This power to weight & burst quality lends them to things like RC electric motors & coupled with a fet, give enormous instant punch & help reduce trigger lag. They are available 'un-cased' & that is what we get. As they have no hard casing, they are more subject to damage & therefor failure. This is why (at the start) they picked up the self destruct rep. You will find them, 'cased' in more and more everyday applications, but the fact you can't (as yet) run them flat, & they 'burst' means the inclusion of additional circuitry & components to monitor & control their performance. In some cases, these additional components outweigh the advantage offered by the lipo & therefore conventional power packs are a better choice.

 

Errrr. & now someone else will sum that up & explain it better. Most likely including key points I've forgotten, or didn't think you would be interested in. :D

 

 

Greg

 

Share this post


Link to post
Share on other sites
ok cheers infected. will be contacting you in a cpl of weeks about a cpl of mosfets! just one quick question would you reccomend using a mosfet in conjunction with a li-pol?

 

Just to back up what infected said, I'd stick a mosfet in any gun (& have, from mac11's through to 11.1 powered m130 sprung semis) that you want to improve the response time on. Regardless of the power source. Deans connector & decent cable won't hurt either. With decent cable, fet & deans, you will find you can actually step down a cell (say nimh 9.6v to 8.4) & retain the same performance you had before the change. Or conversely, the deans/cable/fet upgrade will give (in most cases) in improvement in rof, roughly equivalent to adding a cell (say going from 8.4 to 9.6).

 

& infected's point is very valid, the higher the current, (weather it's lipos, ni-cads or nimh) the more a std switch will burn up. Esp on semi. The mosfet virtually eliminates this.

 

 

Greg.

 

PS, not wanting to seem like teacher's pet, I can throughly recommend Infected's fets. He uses very good quality cable & (if you ask nicely) will tailor the length to suit your particular needs. Off the top of my head, I've used his product in over 10 guns & the only 'problems' I've had are associated with the particularly drastic improvements of rof in higher voltage, sub 300fps guns. (Pistons! :rolleyes: ) Which were easily solved by dropping a cell. Giving the same acceptably high rofs (around 1800rpm) but with the other benefits of a fet & using a lighter more compact battery.

Share this post


Link to post
Share on other sites
You guys can give me a shout out when there is a nice, big, high quality li-po made for a crane stock. One that will out perform my ELITE4700 12v and fit in the stock with my custom SW-EVO. Then we'll talk.

 

That shouldn't be too difficult, but it wont have to be 'big' & I'm not about to do your home work for ya. :)

 

& any way, why change if you are happy with what you have. ;) (a huge heavy lump of a battery :o )

 

 

Greg.

 

Ps. any one want to buy my cast offs: 3x9.6v 1700mah 'j' types, a GnP 10.8v3300mah subc, 2x9.6v3600mah subc's, a std 8.4v 3300 'large' :huh: a 10.8v2000mah 'aa', 2x8.4v2000mah'aa', 12v3300, 12v4300. Oo, what else, ah, best keep the dodgy 9.6v4300 craner, (I never use my m16's/15/4's so it's not worth sourcing a lipo ;) ).

 

Wont be able to give 'em away this time next year. :rolleyes:

Share this post


Link to post
Share on other sites
That shouldn't be too difficult, but it wont have to be 'big' & I'm not about to do your home work for ya. :)

 

& any way, why change if you are happy with what you have. ;) (a huge heavy lump of a battery :o )

 

 

welp, im not one to settle for decreased performance. id gladly strap a weight onto my stock if it means i get to push the envelope of power and speed. Im not going to take a step backwards from my battery which punches you almost 14v and holds well over 5000mah (granted its 5000mah of nimh not li-po).

 

and dont worry, you don't need to do my homework for me, i already have. big is a relative term. i mean big in comparison to other li-pos available for crane stock application. As far as im concerned, unless its going to take me from external to internal storage AND boost performance, its not worth the switch.

 

And, for the record, i'm never happy with what i have. ;)

Share this post


Link to post
Share on other sites
welp, im not one to settle for decreased performance. id gladly strap a weight onto my stock if it means i get to push the envelope of power and speed. Im not going to take a step backwards from my battery which punches you almost 14v and holds well over 5000mah (granted its 5000mah of nimh not li-po).

 

and dont worry, you don't need to do my homework for me, i already have. big is a relative term. i mean big in comparison to other li-pos available for crane stock application. As far as im concerned, unless its going to take me from external to internal storage AND boost performance, its not worth the switch.

 

And, for the record, i'm never happy with what i have. ;)

 

Exactly. :)

 

Although there are 'offerings', the 'cubic' nature of currently available lipos, don't lend themselves to 'tube' fits, such as ar15's etc.

 

While lipos offer an alternative, they are not the answer to every situation & I would not advocate 'chucking money' at the latest trend, just for the sake of it.

 

If it ain't broke,etc,etc. ;)

 

 

Greg.

Share this post


Link to post
Share on other sites
I have a ICS M4 with a PEQ box. Would a lipo fit in it?

 

Lipo's come in all sizes, it's a matter of whether the lipo you want will fit in it. A 7.4v 2200mah 25C lipo is about the size of an 8.4v mini battery, but of course more powerful.

Share this post


Link to post
Share on other sites
Another question... What is the other wire for coming out of the battery?

 

That's the balance plug. There's more details about that in part 3 of the series. It's used to handle voltages for each cell individually (keeps the battery in good shape).

 

 

Part 2 of the series will be published and available on Monday :). IF you are a subscriber, you'll get the info in your inbox as soon as it publishes. To subscribe, check the top right corner of the right sidebar.

Share this post


Link to post
Share on other sites

×

Important Information

By using this site, you agree to our Terms of Use and the use of session cookies.