[mcguyver]

Battery has ABSOLUTELY NOTHING to do with velocity. Now that that's out of the way, it's all about allowable tolerances.

When companies order a part from someone, the more precision in tolerances you ask for will cost you more money. People need to be paid to sort through parts and weed out those that are outside of "spec". If you don't care about tolerances, you will get the best price per part.

When companies build something for a retail market, do they care about getting the cheapest part, or getting the best part? After all, if you want the "best" part, there is a whole marketplace full of people willing to sell them to you for profit, so the manufacturer doesn't need to be concerned with that. It's simple economics.

This holds true for anything that is manufactured from parts, including AEGs.