I used a cheapo one in mine that I got on ebay. Like $18 from china. Yea 1 year warranty, but after 5 months, wouldnt hold more than a 15-20 minute charge with constant use. They would have warranteed it, but would have cost more than I wanted to send it back to china. I dont know how they afford to give stuff away and ship for free too.

But for a us seller from amazon, it would almost be worth it. When it fails you can get a replacement and it'd be cheap to ship back. So it would cost ~$30 for a year. Much cheaper than a crestron one which you get about the same life expectancy.