I bought a couple of HF ones on sale several years back. Don't bother.
I have 3 or 4 BTJs. My oldest one is 8 years old and works great. I don't think my best HF one lasted 8 weeks, maybe days,
If you're willing to spend money on a decent battery then you should be willing to spend money on a decent tender - or just get your battery from HF too. :neener: