Is it possible that it's overcharged? Which contacts to measure?

My Nexus 6 pooped out on me yesterday. The previous night it shut down randomly (Not powered down- just went black and then started back up.) and I didn't think much of it. The next morning it froze briefly and shut down just like last night, except it didn't power on. It was on the charger, but wasn't warm at all as it had been charging all night. I tried to access the fastboot (I had it enabled) but nothing, no response at all. So I had to tear it down. It was plugged in both times it shut down.

Once I had access to the battery connector, I measured it with my multimeter. The two contacts on the sides had "P+" and "P-" under them, like this:

When I contacted my multimeter to these, it registered 4.10 volts. I know this isn't normal voltage for this battery, but shouldn't it still start up? Any chance it ruined the logic board? Upon inspection, the logic board looks perfect. At least the front side of it. The battery looks visually perfect too.

@avanteguarde Any chance you think this is firmware related?

@theimedic @refectio is it bad for an iPhone battery to be above 3.7v? Do you think I wasn't measuring the voltage right?

I was saving up for something else more important and I don't want to buy a new phone right now, so if I can make this one last another 12 months that would be great.