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.
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.
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{ 9 comments… read them below or add one }
Just in the nick of time! You saved 2 G48’s.
Thank you.
Glad you liked it. Credit goes to Rick. We’re just the messenger. I’ll see if I can find some more money savers from the archives. Now that the May issue is at the printer, I got a little room to breathe.
Well damn………..about 3 weeks too late.
Thank you for this valuable information… I was about to throw my garmin 48 but refused to accept it’s working and garmin won’t service it anymore, do some search and find you.
I Really apreciate this guide Thx a lot.
How do you crack open the case in step one?
The case is glued together but will seperate if pryed gently apart. I still get the battery low message even after installing the new batteries, will it go away?
Rob,
I haven’t heard of the message remaining post surgery. Perhaps someone else who has performed this operation can chime in. On a related matter, we visited Catalina plant last week and noticed Chief Engineer and VP Gerry Douglas had an old Garmin GPS 45 on his desk. He said it was still working fine.
Hi,
I came across this page in my search to repair my garmin 48 gps and have tried what was described by Darell. Unfortunately, it didn’t work for me. I had my unit examined by my cousin in law who is knowledgeable in electronics. He identified the battery for me which is the small button like structure standing in the middle of the electronic board with a brown outer covering for insulation and welded on both sides (positive and negative) in to two thin plates of metal which feet is welded into the board. He was offering to look for a replacement battery for me but from my internet research, I believe it will be difficult to find one. He suggested to me an alternative which is to weld out the battery, making sure to remember the positive and negative foot of the plates holding the battery. I welded a couple of tiny wires in place of these battery plate holders (with the help of an electronic technician with expertise in welding small wires into delicate boards like this). Then I welded the opposite end of the wires to positve and negative sides of a CR2032 lithium battery (3 v same as the original battery , only bigger in size) using a battery holder as describe by Darell. I turn the power on and the low internal battery memory alarm is gone and the unit functioned well. I covered the exposed sides of the battery with silicon to prevent contact with the other wires/ electronic board.
Hope this will be of help to you out there.
Thanks, always missed my Garmin 45 even though I have lots of fancier stuff. I bought a 48 on ebay and replaced the battery with a 2032 hard wired in, no holder. A drop of silicone to hold it in place and viola. It was a funny looking original battery!