Stopped by the closest thing to a speed shop that I can reach by land today, a tiny store in the rafters of a furniture warehouse. I noticed a Braille lithium battery sitting in the pile of stuff in front of the counter. This was noteworthy because last I heard, importing large loose lithium batteries was a legal gray area and giant PITA. Me and the shop owner got to talking about these things and I mentioned the rumor that they were just rebranded Deka batteries with an expensive name on them.
Turns out he'd investigated this thoroughly before deciding which lithium batteries to stock at his shop, and found that it's not true. First he called both manufacturers and asked, both insisted it was a myth, but that's probably what they'd say if it were true 
Then he got a Deka for his own Evo X and the Braille I was holding for comparison. He noticed the Deka was physically quite different and seemed cheaply built next to the Braille. Then he found a shop with serious battery testing equipment and had both batteries run through a...battery of tests and the Braille's cranking amps were significantly higher.
So, not saying the price difference matches the quality difference, but they're not the same units with different stickers on them.
