Just to repeat one thing: This thread is about a supposedly "1700mAh" battery with the same dimensions as the original battery.

Such batteries don't exist. Whatever your beliefs are w.r.t. exploding/swelling cheap batteries, be assured that what's announced in that original link (see first post) is a hoax. EVERY ad for a battery claming to have vastly larger capacity as the original battery, without increasing its physical size, is a LIE. That should be reason enough to realize the seller is not a trustworthy one.

Feel free to buy cheap batteries if you want to, but at least stay away from the obvious fakes.

Mugen batteries make a OEM size battery for the N95 that holds another 300mah. They may do the same if the BL-5J is used in popular handsets.

It is possible to cram more in, it is just expensive; hence, $5 batteries are likely to be fakes.

Totally with you on this one - 1700 sounds like a lot - claiming that its the same size as the original one is a joke! I would stay well clear.

I bought an oversized battery from ebay with a new battery cover for my N95 8GB and have been using it for about a year or so. The one problem i can say about it is that the connector terminals on the battery start to spread apart after a period of time so that they no longer hug tightly against the power terminals on the N95 so if i give the phone a sudden jolt or tap i get a reboot because battery gets disconnected in one of those three slots.

The temp fix is to take the battery and use a little pin to bend the two gold contacts in each slot closer together once every 2 or 3 months. But this is only a temp fix as eventually after a year those things suffer metal fatigue and the temp solution doesn't work and after about 4 days or so of bending those contacts back in you'll get the same issue again.
This is a quality control issue that needs to be brought up by the big corporations to the Chinese mass manufacturing plants in China that make these lithium batteries.
The metal on those contacts needs to be strengthened somehow or reinforced.so that 500 insertions and removals don't cause metal fatigue on the contacts resulting in loose power connection causing phone to become sensitive to sudden jars and taps.
After all, we live in the time of accelerometers, mobile tech should be expected to get jarred, tapped and have sudden jerks in motion.

I'm guessing Mugen overcharges for the same China mass manufactured batteries you can get off of ebay.
Anyone want to take a look at their Mugen battery and see where it is made?

Take a look at your original Nokia battery,
its not the productioncountry, its the service and quality (and Name) which increase the price.

Wonder if anyone have tried it? Is it indeed last longer than the original one? 1700ma is like 30% more.