Review (5/5): Norelco Battery Replacement
I replaced the battery in my model 3605X, 14+ year old razor with this product. It has only been installed for about 3 weeks, but so far it performs flawlessly. All NiCd batteries loose their ability to recharge to full capacity over time, and my old battery would only stay charged enough to run the razor for about 3 hours. With the new battery, it works like it did when I bought it, with a full charge being held for a few days. However, you need to dispose of the old battery properly through recycling facilities, as it contains toxic cadmium.
Unless you specifically need this battery for a Norelco razor, you might consider a different Sub 4/5 C battery with tabs, which is essentially what this battery is; the markings on this product do not resemble the original battery that I removed from my razor anyway. Note that replacing the battery with this product likely voids the razor's warranty unless you are a qualified Norelco technician, and it is possible to break some tiny copper wires inside the razor during battery replacement, so do so at your own risk. You will also need a proper set of screw drivers, (3mm star bolt drivers in my case), and a soldering iron to replace the battery.