Nexus 5 update error

[AC Question]

I'm very new to Nexus, just got a used one yesterday (amazing condition 32GB battery running low on juice bu that seems to be an easy fix from what I read)

It's running Android 5.1.1 (reset to factory)
build: LMY48B

pretty simple, trying to update to Marshmallow

phone keeps saying it downloaded an update and it would like to install
the update is always 10.1MB
after clicking install and restart, it just says error then force restarts in like 30 seconds

why is this happening

 

[B. Diddy]

Welcome to Android Central! Try wiping the cache partition, then try the update again. Be aware that this can take up to 5-10 minutes on a Nexus 5: http://forums.androidcentral.com/nexus-5-rooting-roms-hacks/352008-guide-nexus-5-recovery.html