And that's one of the reasons why I think it would be easier to make a portable or hybrid PS5, having such version included in the range since the start (or at least planned since the start even if actually launched later) would solve many problems, dev tools should take it into account and produce games that can scale seamlessly between at least two graphics levels (a third level for premium home units could be added too, and the most flexible engines could let gamers choose their favourite tradeoffs between resolution and frame rate).

https://www.independent.co.uk/life-style/gadgets-and-tech/gaming/fortnite-playstation-sony-cross-platform-xbox-switch-cross-platform-play-a8516081.html?amp&utm_source=reddit.com&utm_source=reddit.com

Mr Yoshida said Sony was aware of the increasing importance of mobile gaming, adding the company needed a "growth strategy including mobile".

He added he welcomed the competition from other platforms as well as traditional gaming rivals.

"I think competition is always good. Healthy, fair competition is always good for the industry and growth," he said.

"I think competition with Nintendo and Xbox is a healthy situation."

Mobile means mobile and mobile games, not portable console. Sony already knows the importance of mobile since they have one of Japan's most popular and profitable mobile games with Fate/Grand Order.

Well there is only one Division in Sony that is growing, hopefully Mr. Yoshida can see the clear and obvious path to growing their Mobile business.

Their IFA conference didn't provide much hope though. The hole thing was how can we connect to our consumers past the point of sale? Here is this Google device with Google Music, Google Movies and TV, Amazon Music, Amazon Video, and Netflix. No mention of PlayStation Vue, PlayStation Video, or PlayStation Now. Well, ya sure as shit won't be connecting to your users after point of sale if you put them on another companies OS and direct them to competing services. 

If 5G, Solid State Batteries, M.2 Storage, and Ryzen Mobile is not the biggest oppertunity to shake things up in the mobile industry, I don't know what is. Between that and the success of PS4 and PSN, there is no blaring horn louder, and no flashing light brighter, the answer is right in front of their face. Now will they see and hear it?

So when do you expect solid-state batteries for mobile devices?

I think we will see a Phone with a Solid State Battery at CES 2019. Not from a major player, but some Start up, or Chinese brand. Then I think Samsung will introduce it in a Galaxy model by CES 2020. Apple will probably be behind them by another year or two. Sony should have a couple of year window to release in the early 2020's. Ideally I would love to see a PS5 and PS5 Portable launch simultaneously, but a Portable may have to drop a year or two later. AMD has been on a nm, nm+  cadence, so perhapps Home devices fall on the nm fab, with mobiles being built on the nm+ fab.

Solid State batteries are still years off. Right now Volkswagen is planning a trial production of solid state batteries for 2024. That hasn't anything to do with mass production, let alone with cheap batteries. This stuff will be crazy expensive in the beginning. So unless some miracle happens, we will not see a portable PS5 with a solid state battery. Maybe a PS6. But just maybe.

As far as I understand Cars will come after electronics. It is a mixed bag, with each company having different target dates, but most of the articles I've read have small electronics coming in the next 1 - 3 years. 

Fisker is claiming that there SSB's will be cheaper to produce than current batteries, and they are looking at going into product of Phine batteries by the end of the year or during 2019.

That is why I think we will see some random Phone at CES sporting an SSB.

Sony is already a big mobile player. They have one of the biggest mobile games in the world

A new portable for regular games and ps now/streaming console that can be connected to TV would put sony in a position to combat both the switch and the rumble of the scarlet device for streaming games while ps5 would follow its hardcore market.