Dirt devil easylite 7.2 v does not hold charge. Can you suggest any fix? Thanks

Sorry to say that the batteries seem to be worn out. Usually this is caused by using it for to short a time each time you use it. Batteries develop a 'memory' after several short time uses, and can only be charged the time it 'Thinks' is a full charge. You can try running it until it almost stops. Then let it sit for about an hour turned off, then turn it on again, and run it till it almost stops. After doing that put it on the charger for 8 hours. Then run it until it almost stops again. then charge it again. That process sometimes breaks the memory problem. If not, you need new batteries- or a new dirt devil.