I've replaced the battery in my 3 year old 200, I did about 3 months back.
I desoldered and soldered the speaker wires. Easy enough to do as long as your eyesight is good and a reasonably steady hand.
The whole process was easy, following the process in the link below. I had to purchase a PH000-50 philips screwdriver for the tiny philips screws holding the board in place, so watch out for that if you haven't got the necessary tooling. I'm sure I'm getting much better performance out of this replacement battery than I ever did with the Garmin battery! The only thing I've noticed is that it seems to lose GPS signal more frequently under trees than it used to... so whether the antenna was disturbed, I'm not sure.
Keep your 200 alive, it's the best Edge out there!
http://weightweenies.starbike.com/forum/viewtopic.php?f=14&t=122698
Also, the 200 is fine with a portable charger for the ride. I used one for ages, until it got to the point the battery couldn't hold charge for 3 hours, then went for the replacement. Use the portable charger in the dark, so the 200 illuminates and navigates me through the unknown....
