What happened with Flightpower batteries
 

I am coming back to fly my E-Flite Z-Yak 54 and have to get new batteries for it. I used different brands 4 years ago including the amazing flightpower which is no longer in business.
Can anyone recommend a good reliable 4S, 14.8, 30C long lasting battery for that airplane? From the other brands that I used all of them got puffy after a few 6-7 min flights.
Your comments are highly appreciated.
JP

;) My two comments here are ;

I have never had any LIPO battery that lasted longer than Hyperion , with ThunderPower being a close second .

And , , ,

If your puffing multiple batteries in a few 6 or 7 minute flights your likely drawing too much current out of them , try reducing your prop pitch a degree or two (replace a 10-7 with a 10-6 or 10-5 for example) .......

I've been buying from RedWing RC. Good selection and great customer service.

David

You didn't say how many mAh your 4S LiPo are (or is "14.8" an abbreviation for 14,800mAh?). But, to tell if you are abusing them, make a note of how many mA are put back into them when you recharge. The rule of thumb is never discharge a pack beyond 80% of its capacity.
EG: If they are 4S 14,800mAh and they take more than 11,850mA (80% of capacity (14,800 x 0.80 = 11,840)) to recharge, they are being over-discharged and any brand's battery will puff when they are over discharged.
If you are using a LVC (Low Voltage Cutoff) setting on the ESC as your signal that the pack is done and you need to land, you are (most likely) over-discharging the pack.

Also, did the packs that puffed come down hot to the touch one or two (or every) times?
If so, the motor pulled more current out of the pack that it was designed for.
When the label on the pack states "30C", 99% of the time it is a total lie. If they are really 5C, you would be lucky.
So, your motor / prop / ESC may all be fine, but your pack is crap.
The distributors that label their pack as "30C" pretty much bank on the fact that most modelers don't stress the packs they own. So, the modelers don't know that they are only pulling 4C or 5C out of the pack that they paid extra for that was labeled "30C" and they think it is a great brand.
That means the pack may be designed for 5C but the label lied.

Your best source of "truth" is too look at the RCG thread on "Battery Load Test Comparisons". This is a thread that has been running for 8 years and is run / moderated by guys that fly EDF and Speed helicopters and have been testing various brands and liPo construction using engineered and repeatable tests to debunk the myths of certain brands being better than others with real data.
They got tired of buying the latest "super pack" and having them catch on fire or puff so bad they couldn't remove the pack after 1 flight. So, they started testing.
Pretty much search the thread for a 4S pack with the mAh you want and you can see which ones work and which ones don't.