I'm seeking a battery for my 700c 36v 500 watt wheel- and I'm wondering if the cases I'm seeing- mostly rack cases- usually come apart to repack with cells when the battery fails? I was leaning to a bottle battery, but became aware even as I bought the wheel that a bottle battery of 10 amps often says it's only good for a 350 or under watt motor- while the wheels seem to be going the other direction- getting higher voltage and more wattage. This was the only pre-built wheel I could find in 700c- I'm not looking to go real fast, just get around short trips with baskets. Does anyone have experience with the bottles and are the manufacturer claims about amps needed accurate or are they after higher priced battery sales? The square and rectangle cases go higher, but are unclear about mounting on an rack- the square ones are usually behind the seat tubes on pre-assembled bikes that weigh much to much and bind you to 26" wheels. any thoughts? I thought this science would be more developed by now- but hostile marketing forces seem to be at play, and they don't seem to favor the consumer on two wheels. Why aren't there frame cases available so the 18650 cells simply snap into place? Or is that already an inherent part of cases? I seem to have seen two different amps listed for 18650 cells in the past couple of days one at .9 amps and the other something like 1.2? Am I mistaken or is there fluctuation between manufacturers, or just confusion over newer developments?