Some laptop battery vendors offer refurbished discount laptop batteries for sale, claiming that most or all of the useful life of the laptop battery has been restored. Why would customers take the risk? Price. Refurbished items are generally cheap laptop batteries that are sold at a fraction of the cost of a new laptop battery.
Unfortunately, their true worth is essentially zero. The reality is that refurbished, cheap laptop batteries don't exist. Though technically possible, the process of refurbishing a laptop battery costs more than manufacturing a new one. The internal impedance of each lithium ion cell in a laptop battery pack must be matched precisely, and there are only a few manufacturers (mostly in Japan) who have the technical expertise required. By the time a skilled technician disassembles, tests, and reassembles a laptop battery, the cost is prohibitive - and that's before the laptop battery is shipped across the Pacific and back.
So what are these so-called "refurbished" discount laptop batteries? They're simply used laptop batteries that have been pulled from older laptops. The problem with old, cheap laptop batteries is that you don't know how much life they have left. All Lithium ion cells offer a maximum of 600 to 800 charge/discharge cycles over 1½ to 3 years of useful life. It's impossible to know how many cycles - and months - have passed since a particular used laptop battery was built, but one should probably assume the worst. In fact, that's just what the sellers of refurbished, cheap laptop batteries do - they generally warranty their discount laptop batteries for just three months.
Sadly, we've heard stories from customers who don't even get that level of warranty protection. It seems that some refurbished laptop battery vendors have such low margins and order volumes that they can't afford to handle warranty replacements. For that reason, we strongly advise all consumers to buy new discount laptop batteries - even if it's not from us!
If you do choose to buy a used laptop battery, at the very least make sure that your vendor is a member of the Better Business Bureau or some other organization that enforces honest business practices among its members. If you're thinking of buying a laptop battery from a private party on an online auction site such as eBay, make sure you review any available feedback to see how other customers fared.
Over time, we expect that consumer awareness will grow to the point that the market for "refurbished", cheap laptop batteries will die off.