Trackpad problems

I'm using an iMac running OSX 10.11.1 and have started to get problems with the (Bluetooth connected) Apple Trackpad. The cursor sometimes responds in a delayed or jerky fashion and sometimes does not respond at all - using a single finger or 'click'. I have tried disconnecting and reconnecting, replacing the batteries, without success. I've gone back to using a mouse because it is just too difficult using the trackpad. So far as I can see there is little discussion of this problem on the community site. has anyone experienced anything similar? Thanks for any suggestions.