[kylec]

The 2015 15" had a 100Wh battery, the 2018 has an 83Wh battery. The 2015 gets better battery life because it has 20% more battery capacity.

[arvinsim]

I wonder if the touchbar is also doing significant drains on the battery.

[giovannibajo1]

That would make sense if they had the same hardware. Different hardware absorbs different current. You cannot deduce anything from battery size.

[nikanj]

I've had the pleasure of upgrading from a 2015 to a 2017. The battery life on the latter is definitely worse, no matter what the official specs say.

[davnicwil]

Yeah I went from 2014 to 2017, and went from broadly not worrying about doing 6 hours of solid dev work without thinking about battery to essentially never feeling comfortable away from a plug.

I'd guesstimate I get at most 3 hours on the 2017 before the battery level gets low enough I have to start planning where I'll next plug in. Not ideal.

[blueboo]

part of the issue is if you have anything other than textedit open, the discrete GPU is on hoovering up all your watt-hours.

[saagarjha]

It is, but I haven't found it to be significantly worse. About an hour less.

[reversengineer]

Many people would describe an hour's difference to be a "significant" change, especially when a scale of around 10 hours total battery life is being considered.

[saagarjha]

Sure, but considering the "fudge factor" that Apple often applies for their battery life estimates ("casual browsing", etc.) an hour isn't all that much.

[jammygit]

I think decaying batteries might drive people to get new machines? Just a suspicion. They do it with iphones :p

[bluescrn]

It’s certainly an incentive to upgrade, but only if the newer model is a clear upgrade...

I suspect that Apple will be seeing a lot of 2015 MBPs brought in for battery replacements...

[wild_preference]

All batteries decay.

[thebooktocome]

I concur.

[hamstergene]

That's kinda the point... Instead of using more energy efficient new gen CPU to add ~3 hours of life, Apple used it to make the already perfect laptop insignificantly thinner and lighter by reducing the battery size.

[kowdermeister]

> You cannot deduce anything from battery size.

physics might have a word with you :)