Will the Powerboost and Sleepy Pi be able to work together for my device?

Question

I'm trying to build a portable PDA like device, based on a RPi and am currently in the process of working out my hardware requirements.

I was looking at the Powerboost 1000C for the purposes of being able to charge the device while it's still powered on (and step up the 3.7v of the common LiPo batteries to the 5v the RPi needs).

I also discovered the Sleepy Pi 2, I figured it could be useful for extending the battery life and getting around the 'always on' problem to allow the device to sleep when not in immediate use.

My understanding of hardware and electronics isn't great and as far as my knowledge goes these things may as well be two black boxes. If I were to connect them up as such

[Powerboost]Power out --> USB --> Power in[SleepyPi]

would the Sleepy Pi be able to serve its purpose of saving power or does the Powerboost always generate its 1A of power and constantly drain the battery (thus making the Sleepy Pi effectively redundant)?

If not, is there anyway I could achieve this*? Please talk to me like I'm an idiot, it's been a while since I've done this kind of thing and even then my knowledge was never that deep

*'this' being:

1. Allow simultaneous power & charging
2. Reduce power consumption through some form of sleep mode

Answer 1

I'm no expert, but I would imagine that battery discharge would be minimal when the Pi is "asleep".

Batteries usually don't drain at max speed unless something's actually using a lot of power.

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One of the bullet points on the datasheet for the DC/DC boost control chip on the Powerboost 1000C specifically mentions low power drain when nothing's using a lot of power:

Power Save Mode for Improved Efficiency at Low Output Power