Don’t Trash that Old Garmin 48 GPS!

The dreaded Memory Battery Low error in your old Garmin GPS 48 doesn’t mean the unit is doomed . .

I was rummaging around the dead letter office at Practical Sailor and came across this bit of advice tucked away in our old Mailport files. Knowing that many Practical Sailor readers, like me, are quite content with a set of charts and a basic GPS showing position, course and speed data, I thought it would be a good idea to resurrect this handy tip. Hopefully, it reaches you before that ye ol Garmin gets chucked out during some overzealous spring cleaning.

Introduced more than 10 years ago, the GPS 48 was one of Garmins best selling handheld GPS units. I like to think of it as the first nail hammered into mighty Magellans coffin.

Sadly, the unit wasnt meant to last forever. Or, should I say, Garmin did not intend to support it forever? Doesnt matter. Sooner or later, the lithium battery required by the internal memory peters out, leaving all but the most industrious owners with a worthless piece of plastic and a bad taste in their mouth.

Fortunately, Practical Sailor readers are the industrious type, and they also have no qualms about sharing their wisdom.

A few summers back, reader Rick McLaren, owner of the 1970 S&S Swan 37, Dulcinea, pointed out that you can replace the GPS 48s internal battery with a your basic CR 2032 lithium battery.

If you want to go really high tech you can order a battery holder to avoid soldering directly to the lithium cell, and also to facilitate future replacement.

The parts required for the battery holder are available from Digikey, so is the battery. Last time I checked, the battery holder was less than a buck.

BS-3-ND Battery Holder-68

Step 1: Crack open the GPS casing around the perimeter of the GPS.

Battery in Garmin 48 GPS

Step 2: Unplug the wiring to make it more accessible.

Step 3: Remove the existing soldered-in dead battery. Both wires should be green, note which one is on the top, that should be the negative conductor – at least it was in McLarens GPS.

Step 4: Solder your new battery holder in place, making sure to connect the negative to negative and positive to positive (see Step 3 for correct identification of wires).

Step 5: Install the new CR 2032 battery. (You may still get the memory battery to low warning.)

Step 6: Install new AA batteries. (The warning should disappear.)

Step 6: Check for proper operation.

Step 7: Reassemble parts and seal with silicone.

Nope, you don’t get 3D contours of the bottom. Nor does the GPS 48 tell you where the nearest Dominos Pizza is. But if you have a chart, it will tell you where you are, and if you know where you are going it will tell you when youll probably get there. Nothing fancy, but it gets the job done.

For our report on the newer Garmin Colorado and Oregon GPS, see this GPS test article.