What is 80% worth?

[Sweller11]

I was very used to the charge limit of 85%. And I understood it. It made sense.

Then, someone at Samsung decided 80% was better for me and my tablets. I still understand it. It still makes sense. Just not as much.

However I also agree with the position that we're being dealt a shorter hand that we bargained for  by buying premium devices with premium batteries.

So I'm left wondering, what does 80% get me over 85%? It seems like a pretty small difference. Samsung must've done sufficient testing to validate the change. More to the point, Sammy must feel like it's valid enough the they chose not to give us any control over it other than to charge it to 100%. Which rather negates the whole equation.

So, does anyone know what the real value is of 80% over 85%?

[TipsyTrex]

Capping at 80% is already industry standard for a lot of technologies such as car batteries, the change was probably just to get things more in line with other standards.

[Sweller11]

It's an industry standard??? That's interesting.

Pointer please?

[Sweller11 · Accepted solution]

In an unscientific (feeble) attempt to answer my own question, I gathered these data points from my S8+ and S8 Ultra. I used a MacroDroid routine to alert me when the charge levels reached 80, 85, and 100%. The results are as reported by the respected tablets.

S8+ (10090 mAh)
---
100% available: 18h 46m left, 1126m
85% available: 15h 57m left, 957m (-169m)
80% available: 15h 10m left, 910m (-47m)

S8 Ultra (11200 mAh)
--------
100% available: 21h 48m left, 1308m
85% available: 18h 32m left, 1112m (196m)
80% available: 17h 45m left, 1065m (-47m)

And so, in my completely unqualified opinion, it looks to me like the move from 85% to 80% resulted in a net loss of 47 minutes of useable battery charge per charge cycle. Whereas the more significant trade off is from 100% to 85% which resulted in a reduction of 169m and 196m respectively.

I also need to point out that 87.3% of statistics are completely made up.

[bill-e]

My Tab S8U has been having charging weirdness since 6.1.  I keep my Tab plugged in 24/7 with Battery Protect and it used to sit right on 85% all the time.  Now it discharges quite a bit and even down to 0v when it should be charging.  I charge off my monitor USB-C which also passes 4k video to my monitor.