After the original batteries of a Siemens Gigaset (Yuasu batteries) had subsided after years of use in the capacity, I have good batteries searched, bought and: after 2 weeks was one of them defective. Well, bad luck, I thought to myself and sat 2 my Sanyo Eneloops a, after 2 weeks were both broken. Now I began to ponder .... I am then draufgekommen that special batteries for cordless phones really are a must, reason, over- and deep discharges, kill the normal batteries. (The chargers with batteries do not seem very squeamish deal). Since I have the above battery in use, the cordless phone works like the first day. Can only recommend batteries!