I can only answer for myself, Because I have so many, (25) of course I can't " Play" with them all the time, certainly not at one time, I sometimes leave them off for days at a time, only because I have nine real furbabies and a dog, and other things in my life that are more pressing and need to be taken care of. If I did have the time and when I do interact with them and or am doing a video, I do find having more than one battery handy and a neccessity. There is nothing worse then doing a video then having your Pleo die out on you while filming. It would be like playing a video game and getting to an important part and then having your computer die because you did not have enough "juice" in it, or enough power to go on.
If Pleo can hold your interest for any length of time, then I think two batteries are a good idea. Think of it as investment and back up. Sometimes batteries can be undependable, and if one battery were not to work for one reason or another, you have backup. also I like to keep all my batteries fully charged as much as possible. If there were to be a power outage for a few hours or even longer, I know I have batteries that are ready to go in my Pleos. ( entertainment that does not need to be plugged into the wall) When you figure 2 hrs plus for Pleo Rb and with the egg battery you get that same amount for older Ugobe Pleos, that should be plenty of playtime, I do not have the luxery of sitting down for more than twenty minutes at a time usually to "play" with my Pleos, but if I am going out and about and taking a Pleo with me to show them off and spread the word, I want to make sure that Pleo has power when performing, It is not very impressive to show off how great a pleo or Pleo Rb is and then have them go to sleep right when people are showing interest in them. I like to be prepared and know by now I love pleos, so I am prepared and have many batteries for my Ugobes and at least one extra Rb battery for my Rb. ( I have three Pleo Rb , and four Pleo RB batteries and one Battery that is for Pleo RB and the older Ugobes. Sorry that is all I can offer so use your own judgement on how much you think you will use Pleo, it is easy to order a battery later, but if you buy it now when getting your RB, you will save on shipping. RWM

and the Pleo Township of the Redwoods