Garmin 128 saga continues...................

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Slowtack

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Opened the Garmin 128 gps and found what appears to be the battery (soldered in 20mm diameter disk with plastic surround) in bottom right corner of the circuit board as you look from the back. Voltage across this measures 2.92V. No visible markings.
I sourced a replacement batttery on Ebay which has just arrived - 50mm x 35mm x 6mm rated at 3.7V. Plenty of room inside the back of the gps to take the larger battery. I guess I will need to remove the old battery so as not to drag down the voltage in the new one. My question is - has my new battery the correct voltage?
 
Slowtack said:
Opened the Garmin 128 gps and found what appears to be the battery (soldered in 20mm diameter disk with plastic surround) in bottom right corner of the circuit board as you look from the back. Voltage across this measures 2.92V. No visible markings.
I sourced a replacement batttery on Ebay which has just arrived - 50mm x 35mm x 6mm rated at 3.7V. Plenty of room inside the back of the gps to take the larger battery. I guess I will need to remove the old battery so as not to drag down the voltage in the new one. My question is - has my new battery the correct voltage?
Click to expand...

Anything like this?
 
Thanks Lustyd - first class photos and advice. Ive just googled the BR2032 and CR2032 which are rated at 2.8V and 3.0V respectively. As the existing battery in my gps is showing 2.9V it seems to me that the battery is not my problem after all! Think I will just have to shell out for a Garmin 72H or similar. I mainly rely on the Garmin for output to dsc radio and low power course and speed readout to a cockpit repeater when engine is off rather than using the chartplotter.
 
Slowtack said:
Thanks Lustyd - first class photos and advice. Ive just googled the BR2032 and CR2032 which are rated at 2.8V and 3.0V respectively. As the existing battery in my gps is showing 2.9V it seems to me that the battery is not my problem after all! Think I will just have to shell out for a Garmin 72H or similar. I mainly rely on the Garmin for output to dsc radio and low power course and speed readout to a cockpit repeater when engine is off rather than using the chartplotter.
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The battery is only there to remember previous position as well as routes/waypoints so the unit should still work if it's flat. What issue are you having on the unit?
 
Its detecting about 10 satellites but unable to establish its own location. None of the menu options for re-initialising will work.
 
Aha the plot thickens!. I seem to recall the time was a bit off when I last looked. I assumed that would be reset automatically when it had finished its initial setup. Didnt know it needed the help of a mere human, so much for blind faith in technology! Great advice all round from everybody here. Much appreciated and thanks to all.
 
It would get the right time from the satellites eventually if it's working. It definitely doesn't sound like the battery is preventing it working but replacing the battery will help avoid a blank start every time so might still help. As the others have said, switch it on for a very long time to prove whether it is still capable of working. If the screen comes on and it can see satellites I'd be surprised if you don't get a fix eventually.
Cheers
Dave
 
I have the same problem with my GPS 128XL, even after hours it didn't get a fix. It may be an issue of the too old internal almanac. In the internet I found a workaround by holding the PAGE button during power on to deactivate the internal almanac. I will try it in two weeks when I will by at my boat again.
 
Slowtack said:
Aha the plot thickens!. I seem to recall the time was a bit off when I last looked. I assumed that would be reset automatically when it had finished its initial setup. Didnt know it needed the help of a mere human, so much for blind faith in technology! Great advice all round from everybody here. Much appreciated and thanks to all.
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not sure you can set time manually I have 3 diff garmins 2 can be set manually the other sets itself and has no manual option , the date can be set though .

if rechargeable batteries when they fade, The clock then goes off a bit . The other thing is, rechargeable batteries charge while the unit is switched on, so if its not been switched on for a long while the battery can be a bit low .
 
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I have a 128. I checked the battery last year (unusually proactive of me) and measured 2.9v. And my unit works fine.

I can confirm that it can take hours to get an initial fix after nearly a year unused. Also I suspect that turning it on and failing to get a fix can slow it down. I tested once with the boat on the hard next to a metal shed. Predictably it couldn't see a single satellite. But it subsequently took all day when the boat was on the water. I wonder if it bins the last fix before finding a new one? Seems a basic error. But it's a basic device!
 
Can I put in a word of warning here?
I have heard of people who have tried to solder in a new battery and the battery has exploded - potentially causing you some harm. I believe it is better to get a battery holder from somewhere like Maplins, then solder that in place and then the battery just slips into the holder. I guess that this also makes future battery replacement simpler as well.
 
Interesting thread.

I have a Garmin GPS120, an older model than the 128 I think, but it has very similar problems.
After leaving it oiver the winter it just cannot find itself or seem to see ANY satellites. The only thing that seems to work is pressing "Quit" whilst pressing the power on button and turning on.

This resets everything, but wipes out all the stored waypoints and routes:( but at least after leaving it a further 30 minutes it eventually finds itself.

I now call it a "student GPS" because it takes a year off to find itself:D

It's a pain in the a**se though, having to input all the waypoints and routes every year. I'm seriously thinking of replacing it with a modern chartplotter.

Problem is, the Garmin is so much more user friendly than the Furuno GPS. But the Furuno has bulletproof reliability...
 
PeteCooper said:
Can I put in a word of warning here?
I have heard of people who have tried to solder in a new battery and the battery has exploded - potentially causing you some harm. I believe it is better to get a battery holder from somewhere like Maplins, then solder that in place and then the battery just slips into the holder. I guess that this also makes future battery replacement simpler as well.
Click to expand...

The link I put up at the start of the thread shows this process with pictures :)
 
I replaced mine last year - I'm almost certain that the cmos battery is a non rechargable lithium cell. Can't remember the number but I ordered mine online. Came with solder tags attached. Just google the battery number when you manage to remove it. I'm sure it's 3v so the voltage you're reading sounds like it's still ok. Mine was totally dead but the 128 still worked ok, just lost the info when switched off.
 
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