After using these Amazon Basics C-cell batteries for over 2 years across multiple devices, I can confidently say they're a mixed bag with impressive longevity but some quality control issues.

The Good: When they work, they WORK. The 5000mAh capacity is legit - my Maglite flashlight runs for months without recharge. The low self-discharge claim holds true too; after 9 months in storage, one battery still had 92% charge!

Real-World Testing: I've used them in everything from LED lanterns to vintage radios. In my Grundig Satellit 750 radio, they lasted through daily use for 9 months before needing recharge. That's better performance than most premium brands I've tried.

The Bad: Quality control seems inconsistent. In my last order of two 4-packs, one entire set measured only 7000mAh discharge (vs the rated 10,000mAh). It took multiple charge cycles to 'wake up' some batteries - something I've never experienced with Eneloops.

Charging Quirks: These demand patience! Using my XTAR VC4SL charger, a full charge/discharge cycle takes about 24 hours per pair. Pro tip: Use the 'CHG' mode specifically or you'll get incomplete charges.

Value Verdict: At their regular $20/4-pack price, I'd hesitate. But when on sale below $15? Absolutely worth it despite the occasional dud battery - Amazon's warranty covers replacements.