Samsung's latest foldables, the Galaxy Z Fold8, Z Fold8 Ultra, and Z Flip, mark a significant shift with the introduction of silicon-carbon batteries. The Z Fold8 Ultra notably receives a 600mAh increase over its predecessor due to these higher-energy-density cells.

However, EU EPREL ratings reveal a trade-off: these new batteries are rated for 1,200 endurance cycles, a reduction from the 2,000 cycles found in the Z Flip7 and Z Fold7. This rating signifies the point at which a battery retains 80% of its original capacity. Consequently, the silicon-carbon batteries in the new foldables will degrade faster than traditional lithium-ion batteries with graphite anodes.

At a rate of one charge per day, reaching 1,200 cycles would take approximately 3.3 years. This limitation is a known characteristic of silicon-carbon battery technology. For context, the Galaxy S26 series shares this 1,200-cycle rating, while the latest iPhones and Google Pixels are rated at 1,000 cycles.