I recommend.....

[toff]

Long time sufferers of my occasional posts, will remember that I bought some thunderpower and flightmax evo batteries. I have recently had cause to regret buying these, as I have had issues with 'stuttering', 'power loss' and 'puffing' ( no, I'm not joking.)
I've used these 3s batteries with my twin jet and radian ( you can hear the power loss and stuttering on the radian video, thats the thunderpower 2200). All were charged and balanced with an Imax B6 ( the real one, not a copy).
All of the batteries were used in the supercub, and never 'overworked'. 28 amps was the most recorded, fresh charged using a 35 amp lipofly brushed ESC and stock motor.)
The only battery that seems to work constantly and consistantly is the zippy flightmax 2200 (20- 25C) , so therefore, I've bought 5 of them.
Best batteries ever, and I'm a cheapskate (and proud of it!), so that is a recommendation!

[flydiver]

A touch of possible reality to this.
Those battery brands have a very good reputation. ANY, and I mean ANY lipo can be abused. In fact I think that lipos are more likely to be abused than used well.
There are folks that use them in high power EDF, jets, or helis (etc.) put 30 cycles on top of the line lipos (since low end ones just don't cut it) then dump them. They can tell when the power is starting to degrade since they need so much. A lower power application won't show this initially but the damage has been done and they start to run down hill.

An abused lipo doesn't necessarily puff. You can just have a degraded sense of performance. It has to do with changes in the internal chemistry and increases in internal resistance.

The 'stock' Cub is pretty easy on lipos (though pilots aren't necessarily). As soon as you start doing the serious upgrades that a bunch of Cubbers do the stock size and C-rating just don't cut it anymore, let alone the low grade PZ lipo as many have found out the hard way.

[toff]

Exqueese me, I did say, I have NOT abused these lipos in any way. My reality is that these lipos ( branded though they are) have not performed as I expected ( to wit - with near perfection) whereas the Zippyflightmax have. The thunderpower and flightmax have been given preferential status as regards charging and balancing, as befits their status, and in spoil brat way, have responded by acting up. Oh, and BTW, I'm quite a Good RC pilot now, and thanks to your informative posts, quite good at reading my lipos state.
So thank you for that. The batteries seem Fuc*ed ( please watch the video, with the sound up)
s461.photobucket.com/albums/qq340/toffas1/?action=view¤t=radian1.mp4

Listen at 1.03 to 1.12.... Thats the newly charged thunderpower.

[flydiver]

I thought you bought them used?
Do I have that wrong?
If not abused in a prior life that is indeed d**ning evidence against them.

[toff]

Yes I did buy them used, but in all honesty, when i originally used them , they seemed great, but the more I use them, the worse they become ( Especially the puffing - in a twin jet, at half power!) I am annoyed!

[flydiver]

OK, I 'think' I'm vindicated. My strong suspicion is they were flown hard and put away hot by the previous owner. A lame lipo will croak after a few cycles like that. A good lipo will take it a lot longer but not forever.
When the performance just started to lag, he dumped them.

You used them under their failing threshold. But the decline had started and soon crossed into your use window. I've had lipos seem fine on one flight and fail miserably the next time out. I think once the chemistry starts to go...well there's no saving it. The goal is to prevent that deterioration from being accelerated beyond it's normal state.
Getting them hot, using beyond their rating (and THAT is a VERY suspicious number I seldom believe), over discharge, storing fully charged all contribute to their decline.

[toff]

Well, I've learned a lesson. Those batteries have been retired, and the zippys turned up this morning, so I'm once again happy. These are new, and will be treated like royalty!

[pauliepilot]

Flydiver my 2200 25c lipos both seem to have less power n stuter now n then like today i was flying the squall at quarter power did stutter and like i say as soon as i notice any power loss i bring it down..alltho tbe last 4 or so flights the lipos do seem a bit warm,but when they were new they didnt even get warm?
Are they are buggerd or neally?

[flydiver]

Feb 19, 2011 21:33:05 GMT 1 pauliepilot said:

Are they are buggerd or neally?

Sounds like it unless it's really cold. Lipos don't like the cold. Keep 'em warm (not hot) until you start to fly. Then the draw should help keep them warm. I use an insulated picnic basket and put one of those neck warmers you can microwave for a couple minutes inside. They stay warm for a good while.

In a nutshell, if you have a lipo that used to work fine and now is not and you are SURE your charger is working up to proper level then it's possible your batteries are on the way out. I think PZ chargers are entirely inadequate for this task and really think you want a charger with a digital readout of charge progress and parameters. Anything less and you are working in the dark.

You can downgrade them to a less demanding application, give them to someone with that kind of need, or trash 'em when you can't tolerate it anymore.

If you aren't OK with replacing them all the time then it's time to study up on lipo care.

[pauliepilot]

It was quite cold today but did have one lipo in my jacket pocket but probly still to cold!!
Stoped useing the hz charger 2mths bk n got a "fusion ethos lx41b" its just finished charging at 12.529v?
Iv had the 2200s at about the same time with "i quote my gf says at least 50 flights"
i say more like 35+

[flydiver]

I'm a bit OCD about my lipos. I put tape on the side and check off my uses. I recommend folks leave at least 20% of their capacity after flying.
Try not to fly to LVC unless you have it set high (3.2-3.4v/cell) The stock LVC is not good. That is something I consider important to pay attention to in an ESC.
I frequently only use 50%. It's a rare day I get close to LVC. I store them in ziplock baggies in the fridge at @ 50% capacity. I never leave them fully charged for any period of time.

But the catch is lipos have a finite life even with good care. Some of my older, seldom used but seldom abused ones seem to be showing their age. I was using a older 2200 3S for bench testing a motor that pulls about 120W and it was hitting LVC (3.2v/cell) with 50% of capacity remaining. It just was not holding up it's end well at all. I think I'm going to make an effort to abuse them a bit more. No sense letting them die of old age and neglect in the fridge.
I'll use lipos like that for teaching on my Slow Stick or other low draw application until it can't do that anymore.

Your charger looks like it ought to do fine.

[pauliepilot]

Fridge Never heard of that but i charge then leave till i fly..next day or 2!
Is it best just to leave with at least 3v per cell then charge a hour or two befor i fly?
Im going to look for the lvc of the squalls esc just to make sure!

[flydiver]

Phase 3 Squall EDF? 4-cell?
You get what you deserve. There are worse things on a lipo than an EDF but not many. It's RTF so I doubt you have any way to figure out the LVC if the ESC is stock. They never tell you squat about specs that are really useful.

Storage = 3.85v/cell
That's why a lot of better chargers have a storage function.
If I'm leaving mine out of action for awhile I shoot for that #. If using in the next week anything from 3.7-4.0v/cell is fine with me.

I charge mine just before use. If they don't get flown I try to get the "top" off even if it means a light bulb discharge at home after.
Sometimes the fridge storage is a pain. I have to take them out long enough to warm up in the ziplock before I charge them.

Prolonged storage at full charge increases internal resistance which decreases performance (C-rating). It does NOT necessarily decrease capacity. Heat makes this worse. One of the hardest things on a lipo is being fully charged and HOT. Storage in a hot garage, shed, or summer car can do them in quickly. The heat can make them go over volt, which is very degrading. It's like deliberately over charging them.

Fridge is not going to help much if you are flogging them with an EDF.

Here, do some reading.
sites.google.com/site/tjinguytech/charging-how-tos/
batteryuniversity.com/learn/

Found the Phase3 site:
www.phase3models.com/Instructions.aspx
2 Squall models, 3S and 4S. Read the instructions on both. Pretty worthless for power train specs.

Found this little tidbit from Graves RC:
[It is recommended that you use a 2500mAh 30C battery (Impulse or Intellect) as a minimum, so that battery life is maintained when you're having that much fun.]
That means it sucks amps like crazy.

[parrothead]

Great information to know.

Thanks guys.

[flydiver]

For folks interested in internal resistance [IR) a bit more and/or have the hots for the new "nano" lipos this is worth looking over.

www.rcgroups.com/forums/showthread.php?t=1384403

There may be less to them than meets the eye, maybe just marketing.
Say 'nano" and they will come.