The major problem with rechargeable battery powered tools is the lack of use that the average person gives them. The batteries are OK for someone who is using the tools on a regular basis, and have a good life as they get a complete discharge before rechargeing. For the average DIY person they rarely get comletely discharged except when left for long periods without use, or they get charged when only partly discharged. None of this treatment is good for the battery so they have a relatively short life in the hands of Mr DIY. I have suffered exactly the same way as you have with power tools but still buy and use them as I need and like the convenience of not having to have mains power available everywhere I have a drilling job to do. It doesn't seem to matter how much you pay for the tools the batteries are all afflicted the same.