17 hours to what percent? If you're using the battery until it gets close to 0, that's about to be expected. Lithium batteries are not deep-discharge batteries.
If you're charging at about 40% (which is where you should). restart in Safe Mode and see how long a fresh charge lasts to 40%. (If it lasts longer that way, there's a "runaway app". Find out which one it is, and stop it. (Uninstall it unless you absolutely need it, then force stop it every time you're finished using it).