[Xperia Z3 Compact General] Infy_AsiX:
I've been researching about batteries out of interest of replacement, better charging maintaining and longevity. Being unable to find a recently manufactured Z3C battery anywhere, I'm setting up a Galaxy S8+ replacement battery with a removed Z3C battery's printed circuit board solder connected. I can't find a good source on lithium-ion shelf life through Google but it's commonly mentioned to be 2-3 years to being considered depleted. I've got the mod working but haven't finished cleaning it up. The leftover space in the device got me curious on the actual capacity limit. I started calculating the differences and ended up writing it all up for comparison. I can follow up with some photos.

Notes

Measured by eye using a steel ruler and flat tool on an official warranty replacement 16W13 manufacture dated battery. The capacity feels depleted maybe 80% or so, so it's considered depleted. Being depleted the thickness may have swollen up to 10%. See sources below on these points.

Dimensions in centimeters

All numbers rounded to two decimal places

Nom = Nominal Voltage

Sony's original battery has an energy density of 2008 maximum technology according to this graph http://2.bp.blogspot.com/-NkSg5gn6ePM/VVPBtPLreJI/AAAAAAAAAoI/-KeFe45ky14/s1600/Pix.png found on the source list below.

Using a case without the back panel easily affords an extra millimeter.

For an extra 0.9mm in thickness a Z1C 127 x 64.9 x 9.5 case can be used on a Z3C 127.3 x 64.9 x 8.6.

Original Batteries

Sony Z3C = 9 x 5.1 x 0.4 = 18.36ml = Nom 3.8V 2600mAh 141.61mAh/ml 0.54Wh/L = 2008 density

Samsung S8+, 2017 density = 8.3 x 4.55 x 0.5 = 18.88ml = Nom 3.85V 3500mAh 185.38mAh/ml 0.71Wh/L (or estimated Nom 3.8V 3360mAh 177.96mAh/ml 0.68Wh/L)

Hypothetical higher densitys

Sony Z3C, if matched 2014 maximum density = (estimated using 0.66Wh/L = Nom 3.8V 3189mAh 12.12Wh, 173.69mAh/ml)

Sony Z3C, if Samsung S8+ 2017 density = Nom 3.85V 3387mAh 13.04Wh (or estimated Nom 3.8V 3285mAh 12.48Wh)

Sony Z3C, hypothetical 0.1 thicker

9 x 5.1 x 0.5 = 22.95ml

If Original 2008 density = Nom 3.8V 3250mAh 12.35Wh

If 2014 density = (estimated using 0.66Wh/L = Nom 3.8V 3987mAh 15.15Wh, 173.73mAh/ml)

If 2017 density = Nom 3.85V 4231mAh 16.29Wh (or estimated Nom 3.8V 4106mAh 15.6Wh)

Sources

Good basic sources in general is scarce through basic searching on the topic of lithium-ion batteries. I think it's because the industry is highly competitive with low margins leading to secrecy in interest of intellectual property (got the gist of this from a few different Qnovo blog articles). Also it's got heavily ongoing academic focused research and development but would be funded and therefore guarded by the corporations . Funny though that my main sources are from CEO's of battery related companies. I think it's a case there of smaller companies with an interest and belief in sharing knowledge to create public awareness. Thus here we are on XDA with some relevant useful facts.

At 80% retained capacity a battery is considered depleted. Capacity loss is greatly accelerated after 80% as is the risk of safety measure failure

https://qnovo.com/what-happens-after-80-percent/. The industry leader in support and sales by model volume, Apple's warranty policy follows this guideline https://support.apple.com/en-au/ipho.../battery-power.

About battery thickness swelling.

https://qnovo.blogspot.com.au/2015/08/72_14.html

This article https://qnovo.com/moores-law-and-snails-law/ has a graph for Energy Density Wh/L by year which I used for estimating what Sony's battery could have been if maximum density was used at the time.

I used Table 4 from http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries to presume the capacity of 4.35V and 4.4V which I used for estimated results. Based like this:

4.30	110-115%

4.35 115-120%

4.4 120-125%