If you have a Nokia phone in the 5100 or 6100 series, you're quite likely to need a replacement battery after a year or two (see my article on batteries), and if you shop frivolously, you will probably pay too much, maybe as much as twice the price you would have paid elsewhere. At least, that's what I found in my survey. Cellmania.com sold the BLS-2 battery for 89.50 after shipping compared to only 43.90 after shipping at Discountcell.com, which represents a price 104 percent higher, more than twice the price of the lowest seller! So you really need to be cautious.

Here is the price list (including shipping) for the BLS-2 battery, for stores that carried it:

Store	Price
WorldPhones.com	US$40.90 (shipping has been added to the price) **
DiscountCell	US$43.90 (shipping has been added to the price)
Buy.com	US$54.99 (shipping has been added to the price)
Marquel International	US$58.49 (shipping has been added to the price)
Roxy	US$69.95 (shipping has been added to the price) *
Cellmania.com	US$89.50 (shipping has been added to the price)
Difference	US$48.60

* shipping charge at Roxy depends on your location, so shipping is not included in that price.

** That price has been added on november 20, 2000, two weeks after the original shopping test, on a suggestion of an unidentified user who told me he found that battery for an even lower price at that store. WorldPhones.com also offers free shipping on orders of more than 50$ when purchased with American Express or Discover credit cards.

Find these retailers and others in my accessories section.

These were OEM batteries. Also note that the aftermarket products give you more options with specialty products that you can't find directly from the manufacturer, at interesting prices. For example, Atbatts.com (an online battery store) sells a Value Line brand 3000mAh Li-Ion replacement battery for the Nokia 5100 series, which means it can have up to 15 hours talk time and 27 days (almost a month) standby time. And they sell for only US$42.95 with a two year warranty... Unless there's fine print that I didn't notice, this really sounds like a good deal over what can be found in the original batteries market. Of course, they are close to one inch thick, but for those who need such a battery talk time, it might be worth it.

Is Aftermarket better or worse?
In general, replacement / aftermarket batteries have longer run-time for a better price than original batteries. But they are not manufactured by the original maker. So what? Some industry experts claim that it is better to use original batteries than aftermarket ones because they are intelligent batteries and aftermarket manufacturers may not comply to every technical requirement. True or false? I'm very skeptical, but there are few ways to verify that claim for sure... except maybe your input.

So I definitely need your input on that matter. Have you tried original versus aftermarket batteries? What is the difference? Have you experienced better or worse results with non-original batteries?