The new Switch Lite and the slightly improved Nintendo Switch have each appeared in photos at the FCC. And, as you’d hope, they’ve both been thoroughly dissected, so we can get a closer look at what Nintendo seems to have changed from the original model (and what it hasn’t).

Nintendo claims that battery life is improved in the Switch Lite relative to the original Switch. And hours of additional battery life is also the only really tangible difference between the slightly updated Switch and the original. But Nintendo isn’t accomplishing that in either device by using a bigger battery. Instead, it’s using a more efficient processor.

According to the photo seen below, compiled with filings from the FCC, the Switch Lite uses a 13.6 watt-hour (Wh) battery, which is actually 16 percent smaller than the 16Wh battery in the regular Switch. Interestingly, the battery inside of the revised Switch is unchanged from the original. It uses the same 16Wh battery.

One obvious reason why the Switch Lite might have better battery life, despite using a smaller battery, is that it requires less power to run. The display is smaller, and no removable Joy-Con controllers means that the Switch Lite’s battery doesn’t need to be used to charge them. Nintendo also said that it’s using a “more power-efficient chip layout.”

Then there’s the new, slightly updated full Switch. There are two ways to get better battery life: by increasing the size of the batteries, or making the processor more efficient. Nintendo is clearly doing the latter. We got a good hint of that from FCC leaks in early July, and Nintendo confirmed that it was using a new CPU just a week later.

Now that the FCC has released photos, we can also see that Nintendo is using different boards with each of its Switch models — and they are each named after important figures in Norse mythology. If you look closely at the bottom of their main boards, below where the processor is, and to the left of the USB-C port, you can see that the original Switch has “ODIN” spelled out on its board, and a corresponding “ODNX01-A2” appears on the processor, likely signifying that it’s the Tegra X1.

The new Switch Lite has “VALI” on it, the name of a son of Odin. So, what does that make the revised Switch for 2019? Not Thor, Baldur, or Vali, actually. It says “MODIN” on it, which may designate that it’s a modified version of the ODIN board and the processor.

We’re going through this tour of Valhalla to make a point: Odin has another son that Nintendo hasn’t used yet: Thor. Essentially, Nintendo still has room to name its rumored Switch Pro after the hammer wielder.

As much as this makes sense, some of this is speculation. We don’t know exactly what Nintendo will do with its boards in the future, and the parts that Nintendo is using to aid in battery life are hidden behind thermal paste and a heat spreader. But, hopefully iFixit and other teardown sites will break them open soon.