Battery life without

After I have generally made no bad experience with third-party batteries, I thought, I'll buy this from Mindax.
The first 2Monate everything worked without problems, but now, after about 5 months, I have one of the two batteries must be disposed already. Although he went to the store ended up after a minute already "full" and you could not make 20 more pictures. Several charging stations (Original Canon) I have tasted. Always the same result.
The second battery is already very weak off and only serves me more than absolute last hedge, when I'm traveling.
Although I use on my 50d first 2 original batteries (500 shots per battery) and another replica (approximately 1100 shots) and am therefore prepared for the most important. Plant one but a larger trip, on which one has no way to recharge the batteries and hopes mitzuhaben with Mindax batteries a decent alternative / hedge, so you have bet on the wrong horse ...