Don't Trash that Old Garmin 48 GPS!

Posted by Darrell Nicholson at 09:40AM - Comments: (6)

April 13, 2010

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 Garmin’s best selling handheld GPS units. I like to think of it as the first nail hammered into mighty Magellan’s coffin.

Sadly, the unit wasn’t meant to last forever. Or, should I say, Garmin did not intend to support it forever? Doesn’t 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 48’s 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 McLaren’s 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 you’ll 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.

Comments (6)

jmm Thanks for your very helpful comment.

I have two Garmin 48's. Both were kind of trashed by leaking AA batteries, probably trying to keep charging the internal batteries. As a result the ends of all the AA battery chamber end (with spings mounted on them) broke off in pieces. Somehow I will need to recreate that end. Any ideas?

Opened one of my mine and found it has the VL-1220 battery on the circuit board like yours. Also found the Digi source for replacement, as you advised. I have no idea how would accomplish desoldering/soldering in such a tiny area. All I have is a pencil tip soldering iron. Again, any advise would be welcome.

Thanks. Len

Posted by: Unknown | April 7, 2014 12:24 PM    Report this comment

I had been seeing that low battery error for a while, and stumbled onto this article. I scalpeled out the old silicone and pried open my GPS48 and looked at the components inside. I noticed that at least on mine, the disc shaped device on the black plastic close to the antenna where the photos in this article place a lithium coin cell, is actually a sound transducer. The two green wires which go through the connector would generate the beep which directs you to hit the page button which then tells you the battery is low. On mine, the real battery is soldered to the board, and has a brown plastic "tire" on it. It is standing up on the board soldered in vertically, visible in the middle picture approx 1/3 of the way from the top of the board (antenna end being "top"). The part is available for about $4 from digi-key but shipping is about $10, due to lithium shipping restrictions on usps. I pried the tack welded battery away from the terminals with a greenie, noting which way the positive terminal was(towards the antenna). Also got the part number. Then I de-soldered the terminals and wicked out the holes. Just for laughs, I powered the unit while the battery was out and it said data lost or some such, confirming the battery was really gone.I soldered the new battery in from the top with a really good soldering station. I then used DSR-5 to clean off the old silicone residue and resealed the unit with silicone. The unit works perfectly and only beeps when I get to a waypoint. If you have garmin mapsource, you can dump your tracks and waypoints, then recover them after this process. The actual part number is VL-1220 (http://www.digikey.com/product-detail/en/VL-1220/VCN/P080-ND/2592). Its a 3V battery, I don't know if a 3.2V is an issue or not.Plus the fact that the original is a rechargeable battery, while the 2032 is not. Have fun!

Posted by: jimm | December 15, 2013 10:37 PM    Report this comment

Thank you for posting this article. I have a Garmin 48 very much in need of this procedure! The 48 was my first hand held GPS and I was sad to see it fade away. I will order up the parts and bring it back from the dead as soon as they arrive!

David Cooper, Traverse City, Mi

Posted by: David C | November 22, 2013 10:27 PM    Report this comment

I think we may still have one of these aboard as a backup backup backup. Guess we should dust it off and check the battery. Will definitely save the article info for future reference if we need it. Thanks!

Posted by: DAVID M | November 22, 2013 9:48 AM    Report this comment

Darrell, just a note of thanks on the piece regarding the GPS 48. I've owned this unit for about 12 years and it finally gave up on memory...all wiped clean. After many frustrating searches on Google I stumbled upon a link to this website and the article. Well, I opened up the case and followed the instructions and decided to order the CR2030 battery holder from Digi-Key. I ordered a second one just in case I ran into a problem. Those folks are outstanding...the total order was $5.23 for two holders and postage. Gracious, what service for such a small order. Anyway, I sat down and went through the checklist and installed the holder/battery. I have since logged in about 20 waypoints, which included several shutdowns of the GPS 48. Memory is just fine, as they all appear intact when the 48 is booted. What a gift. BTW, the top wire is negative as pointed out. Many thanks again to you and Rick McLaren. Without that help the 48 would be history as a decent navigation instrument.

Hank Wood Durham NC

Posted by: Tarheel | December 6, 2012 1:30 PM    Report this comment

thanks for keeping yet another piece of electronic gear out of the landfill. It was heartbreaking last year (Feb 2010) to finally de-install my Loran and toss it when I read about E-Loran (whenever!) not being compatible.

Posted by: Paul P | March 27, 2011 11:20 AM    Report this comment


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