For the battery with different models(especially with different volume),the higher its capacity is, the longer time it can be used.Except for the volume & weight, the higher the capacity is, the better it is.

While for the same battery model, the nominal capacity (such as 600mAh) is also the same, but the actual measurement of the initial capacity is different: for example, one for the 660mAh, the other is 605mAh, then is the 660mAh better than 605mAh?

Actual situation may be the high capacity because of electrode materials in the increase in the initial capacity, and reduce the stability of electrode, after the result is reused dozens of times, high capacity battery rapid capacity failure, and low capacity of the battery is still strong. Many domestic battery manufacturers often in this way to obtain high capacity battery. The users after the second half of the standby time is too bad mess.

Those AA nickel metal hydride battery (which is the AA battery), generally 1400mAh, but also has the subject of ultra high capacity (1600mAh), and the reason is the same.

Adding the capacity of the price is the cost of life-span. The manufacturers do not change the battery material in the article, so it is impossible to truly improve the battery capacity.