Device Inspection after Invalid Reading Notice

Device learning since July 16, 2025, 43% battery, Front Flower Bed
App version: 2.1.0
Serial number: 337-CYU
Mobile device: iOS

I got a notification early this morning for this device: Action Required: Invalid Reading. Problem may be caused by moisture leaks due to dirty O-ring. Followed recommendation of O-ring cleaning procedure. After cleaning outside of device, I opened battery compartment, here’s what I found:

Evidence of slight amount of moisture in battery compartment.

Corrosion (rust) on two battery terminals on the battery cap, with a blue deposit on the other two.

Two of the batteries seemed to have moisture on the negative ends but couldn’t tell if it was moisture ingress or if the batteries themselves were leaking.

Inspection of O-ring revealed no apparent cuts, tears, or other damage.

Removed battery spring electrical board and found corrosion on underside.

My initial thought was to clean the battery spring electrical board as best I could, allow everything to dry out for 24 hours per O-ring cleaning instructions, replace the O-ring, install new batteries, and reinstall the device in the ground. However, I’m wondering if it would be better to replace the battery spring electrical board and/or battery cap, assuming replacement is available?

Also, any thoughts on how moisture found its way in to the battery compartment given there is no damage to the O-ring? Perhaps I didn’t get enough silicone grease on the O-ring during original installation almost a year ago?

Is a year (or until batteries need replacing) too long to wait before cleaning O-ring? My plan had been to wait until batteries needed replacing to clean/replace the O-ring.

Any idea of blue substance on the battery spring electrical board? Could it be from battery leakage? I have had recent experience with Duracell batteries leaking inside my TV remote control and causing issues.

I realize that some of these issues have been addressed in previous threads, but thought there are some unique issues here that may be helpful to others.

Photos attached.

Thanks!

Mark

Hi @kramekooc - Thanks for reporting this.

There are two parts to my answer. (1) How to fix this now, and (2) How to prevent this going forward.

#1 - How to fix this now:
To repair/replace devices with moisture damage, I’m in the middle of of workin on something like the “AppleCare” program for GeoDrops users.

The high-level thinking is this (given my job history before GeoDrops):

  • Apple iPhone or Google Pixel phones have both “IP67 water seals” and “impact and scratch resistant screens” (similar to how GeoDrops has industrial-grade moisture seals)

  • But any moisture or screen damage are explicitly NOT covered under warranty (similar to how GeoDrops moisture leaks are NOT covered under warranty, with the only exception that we find leaks in the enclosure’s permanent seal during RMA inspection, and that this permanent seal leak does not show any sign of physical/environmental/external damage)

  • But since “cracked screens” and “moisture damaged” account for the vast vast majority of smartphone repairs, many companies offer some kind of “highly discounted warranty packages” (ie, AppleCare and similar)

Until we have finalized this exact program, for now to help you (and anyone else) move this forward (since most people are learning about these leaks for the first time), I’d like to suggest a flat $25 + shipping replacement cost, and we’re just going to send you a replacement device. The shipping fee will be effectively the discounted USPS fee that shippo.com or pirateship.com charges us, rounded up to the next nearest $1 dollar, to ship from our location (Los Altos, California) to you.

For your existing damaged device, you have two choices:

  1. Ship your current device back to us. Then we will test the factory seal. If we find factory seal leaks due to our fault, and if your device is still under warranty, we will replace your device for free. Please note that similar to industry-standard RMA procedure, you’re responsible for cost of shipping the damaged device back to us, if you choose to go down this path. Please reach out to us for an RMA repair authorization first, so we know to expect your package.

  2. Alternatively, if you suspect the factory seal is fine, and that the leak is likely through o-ring, you can also choose to assume this is an o-ring moisture leak and not the permanent-seal leak, which we categorize as an user-error. To go down this route, please let us know the exact Serial Number of the device you plan to exchange for a brand new device. We will ask for photo evidence that you break the sensor probes. After that, we will ship you the replacement device. You do NOT need to mail us the old device in this case, since we won’t be able to reuse a moisture-damaged electronic motherboard anyways for our factory-refurbished devices.

To everyone reading this: Please note that this highly discounted pricing is only effective until we have standardized and published the finalized discounted special moisture leak repairs program (not sure what we will end up naming it). Once that program is done, this special offer will get deprecated and we move over to that new program. This pricing is only valid for PURE moisture-only damage. If there is any other damage in addition to moisture (such as but not limited to cracked cases, significantly bent or damaged sensor probes, other types of physical damage, etc), then this discounted $25 replacement cost program does not apply.

#2 - How to prevent moisture leaks going forward:
We’re still studying how to reduce these rare causes of moisture damage. We’ve also been looking at more real-world example of leaks and how they happen. (For example, rare engine oil leaks on low mileage cars, on rare moisture leaks in GoPro cameras, and more).

It doesn’t seem like there’s any correlation with the installation location or even temperature! But we’re still looking into this.

For now, I’d like to suggest the following:

  • Please follow our newly published GeoDrops O-ring cleaning guide. A proper cleaning is not just the O-ring itself, but also the industrial-grade plastic surface that contacts the O-ring. Our guide explains this at length: How-To Guide: O-Ring Cleaning & Lubrication – GeoDrops by Homedigy

  • Pay extra attention to remove any small debris trapped in the O-ring when installing (the small debris is very easy to remove by gently rubbing it off with the Silicone grease). While our O-ring is pretty thick, if the trapped particle is too large, it can still result in an accelerated high-humidity air leakage rate.

  • To go the extra mile (to really really be safe): Clean the O-ring and let the device dry itself twice a year, instead of once a year and let the device . If you do this, I’d highly recommend doing this once in the Spring after the long winter, and the second time in early to mid Fall after the long summer.

  • To go the extra mile (to really really be safe): Consider replacing the O-ring every year as well. It’s not strictly needed, but just in case there is O-ring damage during a long-term in-soil installation removal, since rubbing O-ring against dust, sand, and plant root fibers can cause micro-scopic damage to the O-ring.

  • (ps - since O-ring replacement is relatively cheap, I am considering possibly making this the standard recommended procedure for everyone, we’re still studying this, and I’ll post something once we have more concrete findings)

  • (pps - Note that for your typical engine oil change, it’s now industry standard to always just replace the engine filter and O-ring every time, and don’t bother reusing those, to reduce the change of engine oil leaks.)

Please let me know if you have any questions and if this helps? Also let us know how you’d like to proceeed.

Thanks,
Lawrence

Lawrence,

Thanks for the thorough response, especially the recommendations on how to prevent moisture leaks going forward as this is really what I’m interested in.

While I have no basis for suspecting either the factory seal or the O-ring as the source of the leak, it seems the quickest way to get back into the moisture sensing business for this device is just to have you send a replacement for the flat fee of $25 plus shipping. Please let me know how to make that happen.

Also, if you would like to inspect the damaged device for any potential learnings that can be applied in the future, I’m happy to mail it back to you, just let me know and I’ll get it on the way.

Since most of my other devices have been in the ground for coming up on eleven months, I will be systematically removing them over the next few days to replace batteries and clean/replace the O-rings. Since I still have the spare O-rings that originally came with the devices, I think I will replace them to be on the safe side.

Thanks again!
Mark

Hi @kramekooc ,

Regarding this discussion, can you please send an email to tech-support@homedigy.com while referencing this thread? I would like to confirm confidential details there rather than doing it publicly. I also saw you filing another submission on a different thread, so we can coordinate with that in mind as well if it is experiencing the same issues.

Thanks,

Stanley
Marketing PM
Team GeoDrops