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AEG's / Re: not shooting
« on: July 02, 2011, 09:37:03 AM »Quote from: "KillerDragn"
Yeah, When you say: "Swap out all your plugs", I can only guess the only plug on the gun being the Battery Plugin. Correct
The battery is a Tenergy 7.4v 1600mah LiPo, 20c Written on the battery itself.
Is there anything extra I should know about LiPo's besides the common sense, Can I basically, Store my LiPo in a cool clean environment, and leaving it after i'm done using it (Storing it), would having it not charged after awhile sap the cells? (Curious here, I wish my High School offered a Workshop class with Electronics). Lipo's self-drain is much, much lower than that of nicad or nimh, but every month or two you might want to check them. Store them between 50% and 90% charge, if possible.
Once I purchase a Higher voltage lipo later on (Probably my next purchase as far as batteries, A 9.6v No doubt) I plan to purchase some deans connectors and swap out the Tamiya small type, then do the same to all my batteries (I hear Deans > Tamiya, any day from some people, as it offers less resistance on the current?) Basically, yes. It's still a good idea to swap them out with the 7.4, as your current battery will discharge 32amps at the 20c output. That is greater than the 15amp rating of the high quality, small tami connectors. Lower quality connectors will have lower maximum currents.
Link to the battery if it matturz:
http://www.airsoftgi.com/product_info.p ... ts_id=8211
I'm confident with the gearbox I have within my gun to handle the stress from a LiPo (Going upto a High Torque motor here soon, along with the Deans and 9.6v later on) Again, a 7.4 lipo certainly won't be terrifically increasing stresses or wear on your gearbox, just your rof. If you have a serious issue in your gearbox, it may exacerbate the problem somewhat, however, by increasing your ROF, you decrease the time it takes to fire the same number or rounds, which gives a perceived 'increase' in gearbox wear.
Gearbox if it'd help any:
http://www.airsoftpost.com/product_info ... s_id=33763
I'm not asking if my gun is "LiPo Ready", any gun takes wear and tear, but wondering
This applies to ANY airsoft gun, but especially if you're worried about the "power of the almighty lipo" (/sarcasm)... SHIM YOUR GEARBOX CORRECTLY, and MAKE SURE IT IS PROPERLY LUBED.
Quote from: "sinfulpain"
Don't bother with Tenergy again. I have 2 11.1's where one cell is .5-.75v lower than the other 2 after a days worth of games (I checked the voltage of the pack whenever I got the chance, so I had an idea when/if I needed to change). They're both retired for now, until I remove the bad cell, and convert the pack to a 7.4. They hadn't even seen 30 charge/discharge cycles by the time that happened. Internal resistance checked my #$@. I could build a better pack than that garbage! Sounds like you just need to balance those packs, unless you over-discharged the low cell.
As for storage, store the cells at 3.6 or 3.7 volts per cell. If you store them charged, their capacity will diminish quickly (about 50-70% capacity after storing at full power for a year). This isn't their state of charge I'm talking about, but their physical capacity. It would basically drop from 1600mAh to about 800mAh. Check each individual cell, not the pack voltage, as the individual voltages may vary. I've never seen a lipo build up a memory from being stored charged. In fact, most manufacturers recommend that you store them with an intermediate to high charge (such as 3.6 or 3.7 volts, as you've recommended. I just don't want them confused and think that this means to store them dead). Link to some RC enthusiasts who agree http://www.rcgroups.com/forums/showthread.php?t=593322
I would also suggest charging the LiPo outside, just to CYA. Worst case, you have a char mark on the ground, and need a new charger. Better than having no house! Not as big of a deal if he has a liposac, which the OP said he did. It just fills your house with noxious fumes if it vents. That smell delicious... beware, a delicious sugary smell similar to that of sugar cookies coming out of the oven means your lipo has vented and you are now breathing toxic fumes.
The Deans>Tamiya is correct. REAL Deans connectors can handle up to about 70-80 amps constant. Mini Tamiyas are about 9, and Large are 13. I've found they can handle a bit more than that in an airsoft gun... their 'constant' rating isn't the big factor unless you're sitting on your trigger for greater than 10-15 seconds at a time, but yes, switch these out.
Overdischarging the pack will kill it, and if you charge it after overdischarging it, the chances of it going all Allah Ahkbar on your ass greatly increases! The good news is, I believe that tenergy cells have an over-discharge lockout, meaning that if they're over-discharged, they will just stop working entirely instead of allowing you to charge them with potentially disastrous results.
In short:
1. Liposac (you said you have one, that's good)
2. Good charger, make sure it has balancing
3. USE THE BALANCING FEATURE, it will make sure all your cells have the same voltage, and help prevent over-charging and over-discharging of single cells in the pack.
4. Dean's connectors (they're a real good idea, just do it. They're cheap)
5. Don't stab your batteries
6. Store with an intermediate charge at room temperature.
7. If you fully charge a battery inside during the winter, it will suddenly be overcharged when you take it outside and it's cold. Similarly, if you charge it outside during the summer, and then bring it inside for storage, the voltage will spike. Battery voltage is dependent upon the readiness of the cells to undergo a chemical change, and as such, is temperature dependent. This one doesn't get mentioned much, so I thought I would put it out there.
8. Lipo manufacturers across the board (with only a few exceptions, your battery is NOT one of the exceptions) recommend charging at less than a 1C charge rate. (1C means you charge a 1600 mAh battery at 1600mA, 1/2C means you charge it at 800mA, and 2C means you charge it at 3200mA). The slower you charge, the less permanent damage is done. If you have time, a 1/10C charge rate will leave almost no chemical signature on the cells, and as such will not significantly damage them.