Des someone have the 3600 mah for the n810 ? What is your feedback ?

Wow, this is definitely something that'll fill my needs. Been wondering about those higher capacity batteries. I too would be interested in knowing the thoughts on the 3600mah batteries. Also, does it affect how the kickstand operates? And what's the total runtime on them?

Check these threads.

Battery almost empty after 5 hours with locked N810
Extended life battery?

There is a Suspend-To-RAM application for NIT. I recommend to consider n800-s2ram (it works on N810, at least on mine) provided you keep a bug in mind which makes it use 100% CPU. Killing it, and restarting it, solves the problem.

I have the Mugen Power 3600mAh battery (#HLI-N810XL.) From what I've been able to gather, Mugen seems to have a good reputation. The battery is a little bit thicker than 2 original BP-4L's stacked up together. It fits well into the battery socket space. The empty space created next to the battery (under the add-on cover) could be used to stash something except that the inside of the cover has some strengthening ribs running across it. Even so, I managed to wedge a couple of mini SD cards in between the ribs. This after-market cover is plastic, but it is shaped nicely, fits very well, and is painted the exact same gray metallic color as the permanent piece that runs right above it across the top of the Tablet. In place, the new cover is about the same thickness as the main keyboard section of the Tablet, maybe a hair thicker (I didn't break out the micrometer.) It does not get in the way or impede the operation of the kickstand at all. When holding the Tablet, I always open up the kickstand and slip one hand up between the back of the tablet and the kickstand. This is still possible with the new cover, although it does get a little tight around my knuckles. But it's still a very doable way of holding the tablet. Oh, and the Tablet still slides into the original pouch, although it's a tight fit.
OK, battery life. Actually, I've never put a clock on it. I use the Tablet sporadically and for a wide variety of uses.......some which are much more power intensive than others. But sure, I would guesstimate that the 3600mHa lasts at least twice as long as a new 1500mHa battery.

kenny,

does it still fit in the car mount? ( i use the gps all the time)

theres no way it could...thats my only reason for not getting it right now....as i use the 810 for navigation and as my main source for in-car audio

Ya know, I've been finding that having the extended battery (given it's rather excessive size vs case form factor) isn't really worth it as much as I had thought. Having one of the power extenders handy though has seemed to be the better option, at least for me. Typically under normal use I easily lasts me a good 16 hours or so on the normal battery, and if I'm watching movies or playing music, the extender works well, unless of course I'm mobile, and that's the only real time the extended battery works well. But if I'm doing any battery draining things like movies or music or games, I'm typically either stationary, or using another device to do the music/movies/games.

Ordered the extended and slim Mugen batteries from ETEN. Both arrived pretty quick, but sadly both with not charge. Plug Nokia charger in and you don't get the "charging" on screen. Even leaving it for 24 hours, still apparently not enough charge in the batteries to boot the N810.

ETEN emailed to say return the batteries and they will replace them.

"Jiggled" the contacts on the 3600mAh battery and its now showing as "charging"

mardibloke, it sounds like you didn't get them in there right, or they're not making proper contact.

I agree, the batteries are a good fit in the space, so pretty sure its the contacts, but I'm not keen to start bending contacts on the batteries until I hear back from ETEN, or maybe someone else that has received the Mugen batteries and has found a fix that didn't break anything.