The Garmin GPSMAP 298 battery is not workin no more what type of battery have i to order?

SOURCE: Cracked Screen on my Garmin GPSmap 76Cx

Sorry, that's beyond my scope. You might want to ask on some of the GPS forums.

SOURCE: Garmin GPSmap 76 not acquiring satellites

You need to do an auto locate. This also corrects your time issues (wrong date and/or time will be corrected. To do an auto locate do the following.

1. Start with the unit turned off.
2. If you have a GPSMAP 76, GPSMAP 76C, or GPSMAP 76S, hold down the Page button. If you have a GPSMAP 76CSx or GPSMAP 76Cx, hold down the Zoom Out button.
3. While holding down the first button (Page or Zoom Out), press and hold the Power button.
4. Continue to hold the two buttons until the Satellite page displays. You can then then let go of the buttons.
5. Finally, let the unit sit outside with a clear view of the sky. Allow about 20-40 minutes for the unit to acquire satellites.

SOURCE: Garmin gpsmap 295 will not run from internal battery power

I had the same problem. Reluctantly, I removed the batteries and the 8 phillips screws from the the case back perimeter. Be careful on opening. The unit is designed to open from the top and hinge at he bottom to keep the ribbon cables from being stressed. The unit should open nicely and lie flat on the table with the two bottom halves butted against each other. Get a magnifier and ensure the printed circuit board attached to the bottom half has all 3 screws. (I found one missing that has 2 functions - securing the board and delivering battery power. Mine had wedged against a piece of clear plastic...it was hard to find!!!) I carefully removed the wedged screw and returned to the circuit board left most attach point. Close up the unit and we were back in GPS heaven. Battery power restored!!!! and my $250.00 still in my pocket. Yipppeee.

SOURCE: would like to buy a garmin gpsmap 178/178c owners manual

Contact Garmin and they will sell you one.

SOURCE: battery power trouble

I have discovered an intermittent problem on my 10 year old 295 when powered by batteries.
It appears that the chrome plating is de-laminating from the battery contacts that are either side of the back panel attachment hole. At first glance it looks perfect but if you run a fingernail or other small item across the face of the contact you will see and hear a movement as if there a a loose layer of foil over it. This is causing all manner of faults including 'external power lost, shut-down in 30 seconds' when the external power was not even connected at all!