Strange battery usage screen

[LarryA]

Recently upgraded to 6.0.1 on my Z5 Premium. Overall I'm delighted with the upgrade. The phone seems much more stable and faster. Previously it would freeze every couple of days and require a hard reboot. It would also slow down if it wasn't rebooted regularly.
It's been 5 days now since the upgrade, with no freezes or slow down.
A couple of niggling issues though:
1. The low battery alert kicks in at 30% now and I can't find where to change this.
2. The battery usage graph scale is screwed up. It shows several days on the x axis, with the current usage all squashed up in the current day on the right of the graph. Anyone else have this behaviour?

[Qatrium]

@Z5PremiumUser

1. As for now, you can't change the percentage of battery power when the phone will alert you. A warning was added at 30% in addition to older 15%, 10% and 5%.

2. I think the graph will now resize to include the point at which the phone calculated your battery will deplete. 

[Bearings]

I read somewhere that to prolong battery lifespan, it's best to recharge between 40% to 80%. And to also totally drain your battery once in a while to recalibrate it.

[CameronT]

@Bearings,

I know that was true for older nickel batteries that had battery memory, but I'm not sure if it still applies to lithium-ion batteries. It's interesting if that is true. Do you have a link for that?

[Bearings]

Can't recall where I read that but this is close enough...

http://www.pcadvisor.co.uk/how-to/mobile-phone/how-charge-phones-battery-3619623/

Anyway, Sony will be making "Soft Charging" available in the next update...eagerly anticipating it...

http://www.xperiablog.net/2016/06/20/new-xperia-beta-firmware-with-soft-charging-landing-this-week-2...