Pixel 4a 5G gets modded to take larger Pixel 5a battery

Damien Wilde | Jan 25 2023 - 4:22 am PT

It’s not often we see Android hardware mods attempted these days, but one adventurous Pixel 4a 5G owner has managed to mod their device to take the larger Pixel 5a battery into their handset.

Sure, the Pixel 4a 5G and Pixel 5a look almost identical from afar and include the same Qualcomm Snapdragon 765G processor, 6GB RAM, and dual camera system. Despite only being available in the US and Japan, the 5a came with some notable improvements in the materials used and, most notably, the internal cell size. The Pixel 4a 5G shipped with a 3,800mAh battery whereas the Pixel 5a has a 4,680mAh internal cell.

That’s almost a 20% increase but without a massive physical cell size increase was enough to spur Redditor /u/fakesky– to attempt to mod their Pixel 4a 5G to take a Pixel 5a battery (h/t Android Authority). According to their recount of the mod process, the Pixel 5a’s battery was just “4.5mm taller,” “0.4mm fatter” but “1.4mm less wide” than the Pixel 4a 5G internal cell.

Due to the increased dimensions, some alternations and accommodations were needed to ensure that the Pixel 4a 5G could take the Pixel 5a 5G’s battery. Because the battery wasn’t quite as wide, it meant that they had enough space to move the Pixel 4a 5G’s battery management system (BMS). It also helped that the ribbon connector for both devices was identical, meaning a switch would be simplified somewhat. You can see just how this looks below:

After closing up, they note that there is a very slight “bulge in the back” that is “imperceptible” provided you’re not “feeling for it.” The result of this battery mod is a 17% increase in the Pixel 4a 5G battery lifespan. Of course, if you’ve used the phone every day for the past couple of years, the normal degradation of the internal cell would mean a substantial boost in your potential daily usage capabilities.

The Redditor claims vast experience of phone repair and has even accounted for any potential dangers of battery expansion. Sadly, a casualty in this process is NFC no longer works:

I’ve many years in engineering and PCB design and repair, and from my assessment I’ve eliminated all points of potential failure in the event of expansion, namely the NFC sticker in the back which shaves off just under a millimeter and is a potential conductor, the left side of the battery where the BMS now sits has a comfortable amount of insulation and space for expansion as well.

This mod is not something we’d suggest to the “average” owner, and there are some potential risks unless you are well-versed in phone repair as this person clearly is. That said, it’s cool to see someone persevere with the Pixel 4a 5G and overcome some of the long-term lifespan shortcomings with such a mod.