Touchpad Jumpy

What would be the cause of a jumpy touchpad even after cleaning it, yet its fine when an external mouse is plugged in?

Nope.

And it seems to be jumpy when I have my charger cable attached on a full battery. Also tried reinstalling the touchpad driver. No change. Also have cleaned it.

And the fingers bit wouldnt explain the touchpad working perfectly once an external mouse is connected at the same time :/

Sometimes the settings that control the touchpad are in 2 places: one set of controls in Windows > Control Panel > Mouse, the other in the touchpad driver program > usually accessible in the taskbar icon, or the Programs menu.
You want to check both for conflicting settings (with mouse disconnected).

If you find nothing obvious there, then note all the Mouse settings in Control Panel with the mouse disconnected and then compare them to the same settings with the mouse connected.

And then you may have a driver conflict. Try uninstalling the mouse and it's driver in Device Manager, disconnect the mouse, then uninstall the touchpad and it's driver, then restart the computer.
Windows will install a generic driver for the touchpad on restart. Use that for a while and see if it works better without the manufacturer's driver.

Note: always create a new System Restore Point before doing these kinds of changes so you have a quick and easy path back if things do not go as planned.