Does the Casio CDP-S110 have battery power?

Yes — the CDP-S110 runs on six AA batteries for approximately 13 hours of use. This is one of its most practical advantages over the Yamaha P-145, which requires AC power at all times. Battery power is useful for apartment players who want to practice away from a fixed desk, musicians who travel with their instrument, and anyone who has limited outlet access in their practice space.

Do the P-145 and CDP-S110 have the same polyphony?

Yes — both have 64-note polyphony, which is sufficient for beginner and intermediate practice. You are unlikely to exceed 64 simultaneous notes in normal playing. Where they differ is sound quality: the Yamaha P-145's CFIIIS engine produces more natural-sounding dynamics and resonance than the CDP-S110's standard samples, especially at quiet practice volumes through headphones.

Which is better for an absolute beginner, the P-145 or CDP-S110?

Either is a capable first instrument — both have 88 weighted keys and are honest digital pianos. For most beginners practicing at home with a stable setup, the P-145's better sound will be more motivating as you progress. For beginners who genuinely need portability (small apartment, shared spaces, lessons away from home), the CDP-S110's battery power and slim profile make it the more practical choice. Choose based on your situation, not the brand.