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Kia and Hyundai have opened up research into structural battery packs, which involve implanting the battery packs into load-bearing parts of the frame and body. This would significantly increase battery capacity without removing the cabin or storage room. However, placing cells inside load-bearing components would also make them hard to replace, offsetting this practice. There are three workarounds, though. Let's explore them.

Workaround One: Modular Battery Packs

Currently, EV battery packs tend to be one large unit that, when service is needed, can be dropped and opened, and then the cells, depending on the design, can be removed and replaced. It is time-consuming and challenging without more than a bit of danger if those battery packs become unstable or there is some intermittent internal short.

But if you were to take that monolithic battery pack and break it down into more modular components, components small enough to slide into the gaps in bodies and frames, then you could not only service the primary battery more efficiently by being able to unplug a component after dropping the lower battery pack metal shield but also, relatively quickly, pull and service the components installed in different parts of the car.   

With sensors and software, we can now generally tell which parts of a battery pack need to be replaced, and it is at least possible that, at some future point, this could be made easy enough for an EV owner to replace defective battery packs through, I expect, that'll be a decade or more out.

With 3D printing, you can also significantly reduce the metal used in structural components without sacrificing strength, leaving substantial additional room for these captured cells.

Better Batteries

If we can make batteries more reliable using better chemical formulations or different battery technologies (like solid-state batteries), the need to replace batteries becomes substantially reduced. If treated properly, an EV battery pack should last over 100K miles and 20 years or longer than the expected life of an ICE (Internal Combustion Engine) vehicle.

With a battery design that can reliably last longer than the expected life of the car, the only reason you'd have to replace the battery is if it were defective or damaged in an accident. On that latter path, you'd likely have to replace the component the battery was installed in, so you wouldn't necessarily have to try to remove the battery pack. A defect would be a much larger problem, but testing these captured battery components would need to be rigorous enough to ensure that a defective component didn't make it into the build.

But with better batteries, you could permanently seal wherever the batteries are located, making the resulting structures much stronger without adversely increasing repair costs because you've eliminated the need to repair them in the first place.

Modular Charging

Most EV drivers rarely use all of their battery range; they only need it on long trips. Therefore, batteries built into load-bearing automotive components would not be needed for daily use; they could be maintained at the ideal charge level for the battery formulation and rarely used except for long trips.

While this would put extra load on the main battery pack because the distributed packs wouldn't be used often, the captured battery components would have an almost indefinite service life. If they are rarely used and kept at the ideal charge, these components should last indefinitely, likely longer than the vehicle's expected life. 

Wrapping Up:

Hyundai and Kia are looking at structural battery packs, which can increase range with a possible adverse impact on repairability. However, if the carmaker were to use modular battery packs, it would reduce the related cost of repairs across all of the car batteries; if they had better batteries, the need to replace them would be substantially reduced, and if they implemented modular charging where only the easy to replace batteries were likely to need replacement, you could eliminate the downside to this. These three paths aren't mutually exclusive; an automaker could implement three, leading to more easily replaced or upgraded battery packs.

The result would be far more range when needed, a more straightforward practice for replacing or upgrading battery packs, and a more reliable EV. All of this would substantially improve the EV driving experience. Kia and Hyundai are on to something that could help both companies compete with Tesla and the coming wave of Chinese EVs.

Rob Enderle is a technology analyst at Torque News who covers automotive technology and battery development. You can learn more about Rob on Wikipedia and follow his articles on Forbes, X, and LinkedIn.