Garmin Corrosion

A friend commented that his Garmin Map76cx battery contacts were showing corrosion. He thought it was from minor salt water leaks into the battery compartment. I have a new GPS72 that has a similar battery compartment.

Is the battery compartment on these units supposed to be up to the JIS-7 waterproof rating listed for the units?

Would it do any harm to take the batteries out and submerge the unit with the battery compartment open to wash any salt water leakage out of the battery compartment?

Would it do any good to do the above in terms of reducing corrosion?

Has anyone else had corrosion problems in the battery compartments on the newer models from Garmin?

Thanks for any help you can give me.


not the new one
But the old one (76S) had such bad corrosion that one of the contacts fell off. On all trips I would take the batteries out at the end of the day and sleep with the GPS in my tent to fully dry. The compartment is most definitely not waterproof.

On my last trip I used an Aquapac and never took the device off my deck (in a very wet and rainy place). I didn’t use it much so never had to change the batteries and the compartment looks like it did the day I bought it.

Some people here say they paddle with their Garmin on their deck and it stays dry, but I’ve had two prior ones that didn’t, so used the Aquapac for insurance. I could see through the plastic well enough when I needed to (the color screen is really great) and it stayed completely dry.

I’d call Garmin tech support and find out how to treat the corrosion, then get something to keep it dry.


standard isn’t all that wonderful. Also, there is a lot that can go wrong with the battery compartment seal. A grain of sand for instance …

I’m not familiar with this unit, but formerly worked with and tested high(er) end GPS units. I would not submerge the unit to clean the contacts. Maybe try some baking soda on a q-tip to clean the corrosion off. Inspect the battery compartment seal - look for small imperfections. Put the unit in a drybag.


I bought an Aquapac for it. But when I got home I read the directions on the Aquapac and it had a warning about operating electronics in the pac in the sunlight due to over heating. Since I am in South Texas I took this warning seriously. I did develop a blackened area on the screen of a Magellan GPS that I kept in a simialr Voyager case. I returned the Aquapac and bought a clear top Pelican Case that has some air circulation room. Of course with the Pelican Case I can not operate the GPS without opening the case. I would love to be able to change screens on the GPS while paddling without the trouble (and potential dropping danger) of opening the case all the time.


Timely thread for me
My GPSMAP 76c just had a contact in the battery compartment break off last week. I’ve used it without a drybag since I bought it in 2004. Like you I opened it most nights in the tent to dry it out, but some corrosion started to appear anyway.

I could never figure out what was worse. Whenever I put in in a drybag, condensation seemed to inevitably find its way into the display. When I used it without a bag, it seemed to operate just fine withour the fogging, but there would usually be a little water in the battery compartment…

I guess I’m sending it in for repair now. It has served me well to date. Hopefully it won’t cost an arm and a leg to repair.


I agree with others
JIS7 (which is the Japanese version of IPX7) is dust proof, not waterproof. JIS8 would be the first waterproof rating.

I have had to replace one already. Thankfully, they say waterproof in their literature )or did when I bought mine), so was able to get them to warranty it. But now I keep mine in an aquapack.

Garmins and IPX-7
I have had a lot of trouble with Garmin GPS units with this issue. Somehow Garmin does not consider the battery compartment to be really part of the unit and while the internal components may be sealed to IPX-7 standards the battery compartments are not. I was told by Garmin tech support that there is not an international standard for the size of AA batteries and this is why Garmin cannot make a waterproof battery compartment. I used the Garmin 12 for a long time and had to use silicone sealant around the battery compartment to keep the water out. You had to replace the sealant everytime you replaced the batteries. When you look at the issue of GPS units being waterproof it is rather pathetic. Most will claim they are waterproof to 1 meter for 30 minutes but they are not. I have used Garmins, Magellans and most recently USGlobalSat and have yet to find a model that is actually waterproof to IPX-7 standards. My US GlobalSat took all of three times on the water before it died and there is no way you can use it in a waterproof bag (it is on your wrist). They refunded my money which was nice of them. Just light splash destroyed a unit that is supposed to withstand one meter of water for 30 minutes. Pretty sad.

You Scared Me
My map76 is fine.

So it looks like older model good. Newer model bad.

I wouldn’t rinse a battery compartment with water. Maybe electronic contact cleaner. I might use WD40 and a soft, absorbent paper towel or cloth to get the salt out after a trip.

Put it in a bag!!!

Some kind of sealant?
I wonder if some kind of silicone or other marine sealant that can be peeled and replaced during battery changes would work. Many of these don’t adhere well to plastic.


The antennae port is also a
point of entry for water. I have mine permanently sealed.


apparently deet is a commmon culprit for degrading the rubber and allowing corrosion.


so is the everglades
If you apply DEET properly (with the BACK of your hand) you should never again dissolve anything or numb up your mouth or other body parts.

My E trex was done in by ten days in the Everglades…there was so much rust in the battery compartment that it clearly was not moisture proof…

My new GPS is always dry bagged in an electronics dry bag now.

Battery corrision
Is the corrosion from a water leak or leaving the batteries in to long. I always remove the batteries when not in use. Have you ever had a battery powered light corrode from leaving the batteries in them? Most things battery powered have warning labels to remove the batteries if you aren’t going to use them very often.

Probably not
My friend paddles minimum of 4 times a week and uses rechargable batteries so I think they get changed out fairly often.

On my old GPS I changed out batteries about once per week. With the new GPS72 it may be a little less often, but I have not had it long enough to really tell.

Two prior ones?
When mine failed and they wouldn’t warranty it, I switched to Magellan. Fool me once, shame on you, fool me twice,shame on me.

Battery compartment

– Last Updated: Aug-09-07 9:22 PM EST –

There's no way dunking the gpsmap76c* would be a good idea without the battery cover on, you can see the circuit board down through the hole the latch locks into and can also see vulnerable contacts through the memory card slot.

The claimed rating for this unit, however good it really is, had to have included the battery compartment.


Garmin screen darkened by heat
I have used a Garmin for years but always in an Aquapac. On occasion heat has caused the screen to darken or blacken. This has been easily remedied by submerging the Aquapac in the water long enough to cool the GPS. I always meticuously dry the case and GPS over night so have not had problems with condensation in the Aquapac. A silica gel packet within the case would be a good option to deal with condensation of necessary.

Check the price before they repair!!
I was quoted $135 for all repairs by Garmin, which is why I bought a new one instead of fixing a 3 year old one.


The 1st one was replaced under warranty

– Last Updated: Aug-10-07 6:58 AM EST –

and that replacement was used without a dry bag for 3 years, always carried on my deck.