Just read this Bernard. It is possible you may have a dying and/or defective battery, so it acts erratically. That is, it may show full charge then an hour later show very low power. Sometimes it would take 20 minutes to one hour or so of being on, not even in use, and the battery indicator would go from full to almost zero. I had three such batteries and disposed of them. Such batteries often charge very quickly or not at all. But this only a possibility. Something to consider.
JR