makita replacement battery BL1830 18V 3.0 for MR100 BL1830 BL1815

Quote from mercywhy : I want to buy a makita battery for my drill, the original is very expensive, two packs takes about $180, but for a replacement it only takes around $109, some people said that replacement battery has short life with poor quality, but the price is half compare to the original one, so how should I choose the makita pack:http://www.amazon.com/gp/offer-li...dition=new the replacment pack:http://www.amazon.com/RAVPower%C2...tery+bl180 does anybody can tell me how to choose, any opinion will be appreciate.

in fact, i have bought two packs of this battery, has already used almost two months, to be honest, it performs great, fits perfect with my makita drill and charge fast, and this seller even give me a follow call to see if the battery work well, i feel lucky to buy this great battery with less money, will buy this again, highly recommend this seller to anyone who wanna buy a makita battery. Just as the post said, now this battery is on the deals, only cost $109 for two packs, anyway , thanks