I have had my Garmin 750 for three years. When new the battery would last about 2-hours, I found that to be much shorter than claimed. And about the last year it seems to last about 40-minutes. I began to dislike my GPS.
When searching the Garmin site for battery replacement information I just found the info that it was not replaceable by the end user. What I could find for the costs at having them do the replacement was nearing $100.00. It is obvious that they sell new GPS units and want to sell them.
So, I started poking around the internet and found a video on battery replacement of this model and a vendor for the battery. It looked easy enough, as it was a plugin battery. I was dreading using the soldering iron on the Garmin - but great news as it is not needed.
Really folks, it took about the same skill level as changing the battery on a cell phone (at least the ones I have done). The total cost with shipping was $31.00.
Since I am a new user to these forums I don't know if it is a no-no to mention the retail establishment. But they can be found doing a Yahoo search.
Oh yes, my GPS now lasts 5.5 hours on a charge. Much better than it ever did. My relationship with my unit has been rekindled.