One of the security precautions to prevent robots or hackers from simply causing login failures and then rebuilding the password is to set a password re-creation or regenearation time.  The following tutorial will guide you in setting the password regeneration time in the Prestashop 1.5 Administration Panel.

How to Set Password Regeneration Time in Prestashop 1.5

1. Login to the Administration Panel as an Administrator
2. Hover over the menu bar where it says PREFERENCES, and then click on CUSTOMERS in the drop down menu. Scroll down the list of options and look for Preferences: GENERAL.  Select the Regenerate Password option in the menu as shown below:
   
   
   
   
3. Click in the blank to change the time it will take before you can regenerate the password.  Note that this time period is measured in minutes.  The default time is set to 360 minutes (6 hours).  
4. Select the green SAVE button in the right hand corner of the screen to save the time you have selected.

Setting a minimum time to regenerate a password helps to add security to the process so that automated processes generated by hackers cannot simply change your password.