I have similar situiation, buy Intellect 5000mah battery in SSP, very good performance only 2-3 cycles, then can only recharge to 20% and stop. I just wonder those SSP shop are selling 劣質冒牌貨 !!
I bought 3 x intellect 4600mAH from KWS last year, already soldered packs from one of the popular shops. They have the same problem. I asked them, and they just said need to store with partial charge, and not full charge. But the problem still exists.