Prezlock Fingerprint Padlock with Key Backup, 2keys, Smart P

The Verdict

Let’s be honest: most fingerprint padlocks under $40 are gimmicks. Slow readers, flimsy shackles, batteries that die at the worst possible moment. The Prezlock Fingerprint Padlock with Key Backup isn’t perfect, but it’s one of the few in this price range that actually gets the fundamentals right — and the key backup alone puts it ahead of most competitors.

What You Actually Get

The package includes the padlock itself, two physical keys, and a micro-USB charging cable. The lock body is a zinc-alloy construction with a hardened steel shackle — it’s not military-grade, but it shrugs off casual tampering. The fingerprint sensor sits flush on the front face, and the keyhole is discreetly tucked on the bottom edge. It’s compact enough for a gym locker or a tool chest.

Performance: The Good, The Fast, The Frustrating

The fingerprint reader is genuinely quick. Registering a finger takes about 10 seconds — you press and hold, it beeps, done. Unlocking is near-instant, usually under a second. I tested it with slightly sweaty fingers post-workout and it still read reliably. That’s the headline feature, and it delivers.

The key backup is the smartest design choice here. Most biometric padlocks leave you stranded when the battery dies. Prezlock gives you two physical keys. When the lock’s internal battery runs out (roughly a year of normal use), you’re not cutting the shackle or calling a locksmith. You just use the key. This single feature is why I’d recommend this over cheaper alternatives.

Battery life is a genuine concern. The lock is rechargeable via micro-USB, but the battery is sealed inside. When it eventually stops holding a charge — and it will, after a couple of years — you can’t swap it out. The entire lock becomes e-waste. That’s a real environmental and cost downside. Amazon reviewers echo this: one buyer noted, “Works great for 8 months, then the battery won’t hold a charge. No way to replace it.”

What Buyers Consistently Praise

Across the 200+ ratings at 4.0 stars, the recurring themes are speed and convenience. One reviewer put it well: “I bought this for my storage unit. I don’t carry keys anymore. Fingerprint works every time, even in the cold.” Multiple users mention the 10-fingerprint capacity as a plus — you can register your partner, a roommate, or a trusted coworker without handing over a physical key.

Where It Falls Short

Beyond the non-replaceable battery, there are two notable limitations:

1. No audit trail. This lock doesn’t track who opened it or when. If you need accountability — say, for a shared tool shed or rental property — look elsewhere. This is a convenience device, not a security management tool.

2. Weather resistance is partial. It handles rain fine, but dust and sand can work their way into the shackle mechanism. One reviewer from Arizona reported, “After 3 months in the desert, the shackle sticks. I have to wiggle it to get it open.” If you’re mounting this outdoors in a dusty environment, keep it covered or expect maintenance.

Who Should Buy This

• Gym-goers and commuters who hate carrying keys — this is your lock
• Storage unit renters who want quick access without a keychain
• Families sharing access to a gate, shed, or fence — the 10-fingerprint limit covers everyone
• Not for security-critical applications. This is a convenience lock, not a high-security deterrent. A determined thief with bolt cutters will get through it.

FAQ

Q: Can I use it while it’s charging? A: No. The micro-USB port is for charging only, not power. Once the battery dies, you use the backup key until it’s charged.

Q: How many fingerprints can I store? A: Up to 10. You can delete and re-register fingerprints at any time, but there’s no app to manage them — it’s all done on the lock itself.

Q: Is it waterproof? A: It’s weather-resistant, not waterproof. Rain and splashes are fine. Full submersion — like leaving it on a boat that capsizes — is not.

The Verdict

Buy it if you want a fast, keyless lock for everyday convenience and appreciate the safety net of physical keys. The fingerprint reader is responsive, setup is painless, and the backup key design is genuinely thoughtful.

Skip it if you need a long-term, maintenance-free outdoor lock or require audit trails. The sealed battery means this is a 2-3 year product, not a decade-long investment.

Rating: 4.2/5 — A solid biometric padlock that wins on speed and smart design, but loses points for the non-replaceable battery and limited weatherproofing. For the price, it’s a smart buy for gym, storage, and light outdoor use — just know its lifespan going in.

Where to Buy

👉 Check Price on Amazon →

We earn a small commission at no extra cost to you — this helps fund more honest reviews.

Last updated: 2026-08-06. Ratings and prices current as of review date. Verify on Amazon before purchasing.