They have a new thing now where they are sticking labels on the back of their packs with warranty codes. You have to enter the code into the website within 24 hours of it being delivered to validate the warranty. Smart for them, bad for us. Especially those of us who resell them.
I've placed 22 orders with them in the past 16 months with over $5,000 in batteries and had a total of 1 arrive bad. It was actually sold to a guy in North Carolina and he informed me of it being bad. (I had checked it when it arrived and it was fine but another story)
I accepted the return, sent it to HK, and about 5 weeks later had a new battery.
I've also had 1 charger arrive dead.
That's 2 items out of more than $5,000 worth. Maybe I'm lucky, I don't know.
As stated, you could buy 5 batteries, have 2 come dead, and still have 3 good ones for less than a single MaxAmps pack. To me it's worth it. To others, not so much.
I have $850 worth of lipos on the way that I will be selling and I personally will warranty every one of them. No dealing with HK so let me know if you're interested.