Lithium-Polymer (LiPo) Battery Primer

[greg]

So what will happen if I connect my Systema Turbo up to the mains?

 

 

Greg.

[infected]

So what will happen if I connect my Systema Turbo up to the mains?

 

 

Greg.

 

Do It! Just don't hold it, have a fire extinguisher handy, and an exhaust fan. And I take no responsibility for your actions.

[johnyew]

I'm not even using a lipo specific charger, just a normal benchtop power supply and digital multimeter to monitor voltage level. The lipo's are charged in constant current mode at 1C until reaching 4.0V/cell. Then I'll switch to constant voltage mode until it peaks at 4.2V and I'm done charging. Takes about 1 hour or so.

[infected]

Wouldn't it just be easier to have a charger that does that for you? That's why I use the Trition 2. Just set it and then you've got nothing to worry about. I wouldn't leave it unattended (like run to the mall or anything), but you wouldn't have to watch the charge and such and change charging methodology. The charger handles it all for you.

[hugh_b]

Made the switch to li-po's today, went out and bought a pretty fancy fusion charger, flightpower 11.1v 2100mah 20c battery, li-po charging sack, and some connectors that a lot of the rc guys are using that are easy to wire up and have gold connectors so no worries about resistance! The whole set-up cost me £110-120 but most of that was the charger. Looking forward to trying it on my new kwa m4 this weekend!

 

EDIT: Your articles have been a great help infected! Thanks

[infected]

Thanks for the thumbs up there hugh_b. I've got several articles in the works covering quite a few things from grenade shells, to an aeg, to reviewing retailers so keep your eyes open for more stuff.

 

I will be reviewing the Elite Lipos soon, as I have acquired a 7.4v 2200mah which will be used in my Dboys SCAR assuming that arrives FINALLY on Monday morning. I'll skirmish with it on the 12th of this month. So look for that lipo review soon.

[johnyew]

I already had the benchtop PS and multimeter and seeing how a good lipo charger costs, couldn't convince myself to get it. Besides, I charge while I'm tinkering with my guns on my workbench.

[dinj]

Fantastic thread, filled with very useful information on the whole subject.

 

This thread has piqued my interest in moving away from NiMh battery packs and towards LiPo's... at the moment I use an 8.4v 4400mah NiMh in my stock CA M15A4 and G&P Stubby Killer. The M15 is fine, the battery sits in the full stock... but the Stubby has been wired to take the battery externally (the battery sits in my vest).

 

Now... there was mention a couple of pages back that Greg was going to test the FlightPower Evolite 7.4v 800mah LiPo in his AEG... as this is one of the few batteries I've seen that will fit in a buffer tube, I was wondering if the results were in? Stubby is running about 295fps (indoor CQB use mainly). Will the FlightPower battery be ok in there?

 

(The plan is to get a mosfet in both AEG's at some point, so I don't want to go too mental on the battery front at the moment for fear of having to replace a piston, the trigger contacts, or both...)

[infected]

Now... there was mention a couple of pages back that Greg was going to test the FlightPower Evolite 7.4v 800mah LiPo in his AEG... as this is one of the few batteries I've seen that will fit in a buffer tube, I was wondering if the results were in? Stubby is running about 295fps (indoor CQB use mainly). Will the FlightPower battery be ok in there?

 

GREG! Get in here an answer the man's question! (cause I want to know too)

[Kraut]

Anyone know where I could pick up a 7.4v lipo that would fit under the receiver cover of an AK (AKA stick battery)?

[LordElpus]

1stCommando can probably confirm, but the Duramax 11.1v Nunchucks should fit.

[Boom3r]

GREG! Get in here an answer the man's question! (cause I want to know too)

 

 

I've just fitted an Evolite v2 7.4v 800mah in the stock tube of my L119a1. fits very nicely, rate of fire is comparable if not better than the 8.4v intellect 1400mah that I was using before. Not quite as good as the 9.6v 1400 I also have. The firefox 11.1v 1200 mah gives and absolutely insane rate of fire in an aeg producing 350fps.

[tangman]

...

 

Now... there was mention a couple of pages back that Greg was going to test the FlightPower Evolite 7.4v 800mah LiPo in his AEG... as this is one of the few batteries I've seen that will fit in a buffer tube, I was wondering if the results were in? Stubby is running about 295fps (indoor CQB use mainly). Will the FlightPower battery be ok in there?

 

...

 

 

GREG! Get in here an answer the man's question! (cause I want to know too)

 

Here ya go

 

 

Gearbox consists of

 

Stock CA M15A4 CQB Gearbox except for a Systema M100 instead of the stock CA Spring, and a Guarder Air Nozzle (apparently the CA ones suck balls?). It is firing at 345-350FPS with 0.2's

 

And I'm using a G&P M120 Motor there, so unless you have the equivalent expect a lower ROF.

 

The cells were at 3.8v each.

 

Any more questions please feel free to ask

 

EDIT: Last week I used the setup as seen in the video but that was with a stock CA Spring and CA Air nozzle and was only doing 275FPS with 0.2's.

 

I fired about 2,000 0.2's that day on a fully charged battery (4.2V each cell) and by the end of the day it was at 3.75-3.78v each cell

[dinj]

Fantastic, thanks for that. Time to order 2.

 

(And also time to seriously consider taking apart my M15A4 and fitting a mosfet, and maybe an 11v lipo... )

[infected]

(And also time to seriously consider taking apart my M15A4 and fitting a mosfet, and maybe an 11v lipo... )

 

(I know where you could get that mosfet ).

[dinj]

I bet you do

 

When the time comes (probably some time in the next week if I know my attention span ), you'll be the first to know.

[greg]

GREG! Get in here an answer the man's question! (cause I want to know too)

 

 

Ok, ok, I'll give it ago tommorrown night.

 

 

Greg.

[johnyew]

I already have two EvoliteV2-8002S on order. I'm going to use it as a replacement for stick batteries. That video just happened to ease some of my concerns. Thanks again!!

[johnyew]

Anyone know where I could pick up a 7.4v lipo that would fit under the receiver cover of an AK (AKA stick battery)?

 

Kraut,

I have the Flightpower EvoliteV2-8002S on order. Based on the dimensions of the pack, i made a styrofoam mockup and its a 'snug' fit within the tube but plenty of space if under the cover. Once I get the actual packs, I'll post pics.

 

 

Once again, I would like to thank Greg for recommending the Flight Power brand of LiPos. Great product.

 

Try Flight Power Evo30-2000-2S as a replacement to the 8.4V mini battery

[Boom3r]

As well as using a 7.4v 8002s Evolite v2 in my L119a1 stock tube. I've also replaced the truly awful batteries that go with the TM Mac 10 with an 7.4v 1345 Evolite. Given that with the nineball upgrade kit and the new battery the combo works really well though I, could do with fitting a mosfet I think.

[jumper]

for those of us with more milspec buffer tubes , like G&P and Systema. would adding two 7.4v 350mAh packs in parallel 350+350 = 7.4v 700mAh work? they have a slightly slimmer width profile and would fit better in the tube.

 

I'm refering to the smaller version of the pack everyone else uses. the Evoflight 2s 350.

[Fly'n Brian]

Just saw this listed by King Arms, but haven't seen it available anywhere yet.

 

They have a buffer tube made to better fit Lipo batteries.

 

http://www.kingarms.com/productpage.asp?prodid=1435

Stock pipe with marking for M4 Collapsible Stock. Designed to store 11.1V 1100mAh 15C Lithium battery (KA-BAT-10).

The battery can be inserting completely into the pipe. Package included 2 types of stock pipe cover.

 

[jumper]

Just saw this listed by King Arms, but haven't seen it available anywhere yet.

 

They have a buffer tube made to better fit Lipo batteries.

 

http://www.kingarms.com/productpage.asp?prodid=1435

Stock pipe with marking for M4 Collapsible Stock. Designed to store 11.1V 1100mAh 15C Lithium battery (KA-BAT-10).

The battery can be inserting completely into the pipe. Package included 2 types of stock pipe cover.

 

Looks like you need to cut down your receiver or get theirs to go with it. However if their batt stats are true that battery is better on power than the 7.4 evoflight commonly in use.

 

15C x 1100mAh = 16,500 = 16.5 amps

20C x 800mAh = 16,000 = 16 amps

 

hmm.. might be worth the investment... if they can give me a price that is.

[greg]

As well as using a 7.4v 8002s Evolite v2 in my L119a1 stock tube. I've also replaced the truly awful batteries that go with the TM Mac 10 with an 7.4v 1345 Evolite. Given that with the nineball upgrade kit and the new battery the combo works really well though I, could do with fitting a mosfet I think.

 

 

After using the same bat for the same thing, I found you can pop one of infected's ab fets in the space at the front, under the inner barrel.

 

 

Greg.

[greg]

Ok, ok, I'll give it ago tommorrown night.

 

 

Greg.

 

 

Well, it's er, ok.

 

The only bat I had, was for an Mp7 with the tm connectors on, so I had to bodge connection & with about 4 different leads involved I probably added a bit of load .

 

But It turned over a 1 jule gun fine. Not stunning but fine. I have no rof counter at present, so can't really give a comparison, but, like the mp7 it is used for, rof, was similar to an 8.4mini nimh.

 

 

Greg.