This is a guide to help those who wish to use LiPo batteries in their guns. All this info is for guns that are stock, or mostly stock. Upgraded AEG's will differ, depending on what parts you use, and what you plan to achieve out of that said gun. However it will still give you an idea of how to properly handle and use LiPo's.
First a little info about these batteries.Are LiPo's safe? Will my battery blow up?
Yes, LiPo's are safe... The real question is, are YOU safe? Provided you choose the right battery, and take care of it properly, you, your battery and your gun will all remain unharmed. I've shot LiPo's point blank with a 400fps AEG, smashed and crushed them on rocks, thrown them at trees, and put them through hell and back again. As long as the battery has not been punctured, over charged, or over discharged, it will NOT blow up.
Please watch this video, it will help give you the idea of what kind of abuse they can take.How can I prevent my LiPo from failing?
The most common way for a LiPo to fail, is by over charging, or over discharging. A high quality charger with return volt sensing and automatic cutoffs can be a big help. They will monitor the battery and make sure it is charged properly. To prevent over discharging, you can use a volt tester. If you experience a noticeable decrease in the ROF of your AEG, stop using the battery and test the volts. A 11.1v battery actually has more volts then what is listed. The listed voltage is the minimal voltage of the battery. For example: A 11.1v battery will read around 12.6 volts at it's maximum charge. If it drops to 11.1v then you need to stop using it. Same goes for 7.4v LiPos. When the ROF of your AEG decreases, test the volts. If it is at the listed voltage (ex: 11.1v or 7.4v) then it is time to stop using it, and recharge it. If it drops below the listed voltage you over discharged it and your battery is no longer stable.How do I make my gun ready for a LiPo?
A very common problem with LiPo's is burnt out trigger contacts, burnt out wires, and burnt out connectors. This can be prevented by installing thicker wires, a new connector, and a MOSFET. I won't cover to much on MOSFET's, those are a different story, but you can get excellent MOSFET's from Hunterseeker Armory and Extreme-Fire, just to name a couple. As for wires, most stock wiring will hold up, however some brands like G&G use very thin low quality wires, which can burn or melt. Either way it would be a good idea to rewire your AEG. Some AEG's have limited space, while others have more. The most common size (while being the smallest I would recommend) is 16-AWG. As for connectors, I would replace your stock connector with Deans or Bullet connectors. These connectors can handle much higher loads, and will not melt or burnt like your stock connector would. All this will not only prevent the electrical components on your AEG from burning out, they will also increase the efficiency and performance.
The next step is your gears, piston, etc. As long as you upgrade your plastic bushings to metal bushings, that is really all you need to do (on a stock gun). You will also want to correct the AOE, re shim, and re grease. Correcting the AOE, re shimming and re greasing are very common, and should be applied to any AEG, upgraded or stock. There are many guides out there on how to re shim, re grease, and correct the AOE.
Depending on what kind of ROF you want to achieve will depend on what kind of upgrades you need. When your gun is cycling at a higher then normal rate, a common problem is 'pre mature engagement'. This refers to the piston moving so slowly, that the sector gear prematurely catches it before it has fully reset. On a stock gun this is usually not a problem. However some guns, like TM's, have weak springs, so this could be a problem, and you may need to upgrade the spring (in a Tm that would also require upgrading the bushings and gears).
I would also recommend upgrading the piston. Depending on what spring you are running will depend on what piston you need. Generally most stock pistons will hold up. TM makes very nice stock pistons, so if you want something that will last if properly installed, they can be pretty cheap and effective. Again, this all depends on your setup.
On most guns (with the exception of CA Sportline, TM, and G&P) the stock gears will hold up just fine.
That is pretty much all you need to do to get your gun to handle a LiPo. As long as it is tuned properly, there are not many upgrades you need, other then new electrical components as stated earlier, as they tend to be the first to go.
In the end, most guns will only need a MOSFET and a new connector like a Deans connector, then just fine tune the gearbox. So it's not that expensive to get your gun ready for a LiPo (a MOSFET, Deans connector and other things needed to fine tune the gearbox (like shims, grease, washers or sorbo for AOE, etc.) can be had for less then $50).What charger do I need? How do I properly charge a battery?
This depends on your budget. Chargers can go for as little as $3 (don't bother, there crap, as you would expect) to a few hundred $ (over priced IMO). I would go for a mid priced charger, such as the Thunder AC6. The thunder AC6 can be purchased from http://www.hobbypartz.com
for $55. This is one of the best chargers you could get. It's cheap, high quality, and charges both LiPo's as well as the standard NiMH/NiCd. Another thing you need to do, is balance the LiPo's. You ever wonder what that little extra connector on the end of a LiPo is for? It's called a balancer. You plug that into the charger, and it balances the battery cells, to make sure all the battery cells are charged equally, and also monitors the batter pack. These batteries do not need to be discharged like NiCd's. Just program the charger, plug it in and your done. If you are not going to use the battery for a long time, I would recommend discharging it a little. Do not over discharge it as that will kill the battery. The thunder AC6 has a "storage mode" which does all the work for you. As for how fast to charge it, you should charge it at 1amp per every 1000mAh. ex: I have a battery with 2200mAh, so I charge it at 2.2amps.
Here's a video on how to use the charger.What kind of battery should I get?
Well that depends. For a completely stock gun, I would not exceed 7.4v 20c. With a properly tuned gun (Corrected AOE, re shimmed, re greased, MOSFET, new connector, etc.) I would not exceed 11.1v 20c. Now, you can upgrade your gun to handle batteries like 14.8v and 18.5v, however those batteries are incredibly powerful, and if you plan on using one, you better have enough experience not to need me to tell you how to upgrade your gun, so I'll leave that aside.
Most airsoft made LiPo's (like the ones sold on GI and other airsoft sites) are over priced, underpowered, and are not stable. I prefer to purchase LiPo's from http://www.hobbypartz.com
There LiPo's are very high quality, and the price is right. When choosing a LiPo, it is important to make sure it has enough output to power your gun. I would not go below a capacity of 1000mAh, otherwise the battery will not last very long, and will not have enough potential power. Another thing to consider is the C rating. A good C rating for a stock gun is 20c, as this generally provides plenty of power for your AEG. Can a LiPo over power my motor? How do I know if a LiPo is to strong?
The motor will only draw as much power as it needs, any excess power is not put to use. ex: If the motor only draws 20amps, and your battery can deliver 50amps continuously, that extra 30amps is not used. Again, you can not over power the motor, so don't worry about a battery that's to powerful. But remember that it is possible to under power the motor. If the motor needs to draw 20amps, and the battery can only deliver 10amps continuously, the battery will over discharge, and potentially catch fire.What side affects occur to my LiPo if it has been over charged/over discharged/etc. What do I need to look out for?
Individual cells reading below 3.7v,
"Puffed" LiPo cells,
Reversed polarity (red = positive, black = negative),
Puncture wounds anywhere on the battery (especially the cells),
Exposed or touching wires.
When discharging a LiPo, or you have been using it for a long time, it is important to check the voltage (as stated earlier), and make sure the cells do not drop below 3.7v. If they do, that is one of the many signs that the battery is not safe to use.
Another thing to look out for is "puffed" LiPo's. The LiPo will puff up, expanding like a balloon. Obviously this is very easy to sport. This can occur if the LiPo shorts out, has been over charged, or has been over discharged.
Another thing, is reversed polarity. This is when the + and - are reversed, which can damage the battery, as well as the charger. If you use a battery pack with reversed polarity on your AEG, it will not break anything, the gun just won't shoot, as the motor is spinning the wrong way. It's not something incredibly dangerous, but you really don't want to do it
Puncture wounds will also kill the LiPo. These types of batteries are actually quite hard to puncture, so unless you shoot them with metal BBs at 500+fps point blank, not much will happen. If the battery is punctured, it will start smoking, puff up, and potentially catch on fire. You really don't want to puncture them.
Shorting out the LiPo will also kill the battery. A common way this happens is the red wire (+) and the black wire (-) are touching, which will cause sparks, and short out the battery. As long as the (+) and (-) are kept apart, you should be safe. If a LiPo shorts out, it will start to puff up, smoke, and potentially catch fire.
As long as you use common sense, and use LiPo's properly, these batteries won't do you or your gun any harm.Recommendations (brands, discharge rates, etc.)
Recommended retailers; http://www.HobbyPartZ.com http://www.HobbyKing.com
Recommended C rating/discharge rate; Generally 20-25C is good for both 7.4v and 11.1v LiPo's used on stock guns. Also, try not to go below 1000mAh, or it won't have enough juice to keep up with the discharge rate.
Recommended brands for batteries; Zippy, Turnigy, Turnigy Nano-Tech, Blue, Gens Ace, Sky, Rhino.
Recommended connectors; Deans or Bullet.
Recommended charger; Thunder AC6
Hope this helps anyone who wants to convert to LiPo's, and is wondering what they need and where to buy it from.