Question 1

the two camera views on the S350 are out of sync in the app, the wide angle is like 5 seconds behind the telephoto

Accepted Answer

DIAGNOSIS This is a streaming latency issue, not a recording problem. The two video streams are taking slightly different data paths to your phone, often because one stream is being processed or prioritized differently by your network or the eufy servers. FIX First, check your local network. 1) If you're on Wi-Fi, try moving closer to your router. 2) A quicker test is to switch your phone to cellular data (if you have a strong signal) and see if the sync improves. If it does, the problem is your home Wi-Fi congestion. Try rebooting your router and any network switches. The goal is to give both video streams a clear, fast path. IF THAT DIDN'T WORK The issue might be within the eufy app's cache. Force close the eufy Security app completely on your phone, then clear its cache (on Android: Settings > Apps > eufy Security > Storage > Clear Cache; on iOS: offload and reinstall the app). Log back in and check the live view. This clears out temporary data that might be causing a playback bottleneck. HEADS UP When you review recorded events, they will be perfectly synchronized. This sync problem usually only affects the *live view* stream. If you need to monitor in real-time and the delay bothers you, try viewing only one lens at a time in full-screen mode, which often reduces the latency.

Question 2

i get a 'failed to format' error when i try to set up the homebase 3 microSD card for continuous recording

Accepted Answer

DIAGNOSIS The HomeBase 3 is picky about the microSD card's format and type. Cards that aren't formatted to the correct file system (exFAT or FAT32), are too slow, or are simply defective will cause this error. FIX Start with the card itself. You need a high-endurance, Class 10 or U3, A2-grade microSD card, 16GB to 512GB. Once you have a compatible card, format it on your computer first. 1) Insert the card into a computer (using an adapter). 2) Find the drive, right-click, and select "Format." 3) Choose exFAT as the file system (or FAT32 if the card is 32GB or smaller). 4) Click "Format." After it's done, safely eject it, insert it into the powered-off HomeBase 3, power the HomeBase back on, and try formatting again through the eufy app. IF THAT DIDN'T WORK The issue could be with the HomeBase 3's own software. Try resetting the HomeBase's network settings. On the back of the HomeBase, press and hold the sync button for 10 seconds until you hear a prompt. This won't delete your cameras, but it will reset network and some accessory settings. Then try the SD card format process in the app once more. HEADS UP Never remove the microSD card while the HomeBase 3 is powered on. Always go into the eufy app settings for the HomeBase and select "Eject SD Card" first, wait for confirmation, then power down the HomeBase before physically removing the card to avoid data corruption.

Question 3

the battery on my S350 drains super fast even though it's plugged in all the time, says 'charging' but never gets to 100%

Accepted Answer

DIAGNOSIS This is a known behavior, not necessarily a faulty battery. The camera is designed to run primarily on wall power and use the battery only as a brief backup. To preserve the battery's long-term health, the software often keeps it at a partial charge, like 80%, when constantly plugged in. FIX First, confirm you're using the official power adapter and cable that came in the box. Off-brand chargers often don't provide enough consistent power for both operation and charging. If you have the right gear, try a full power cycle: 1) Unplug the camera. 2) Let it run on battery until it powers off (or until it gets below 10%). 3) Plug it back in and leave it alone for a full 24 hours. This can recalibrate the battery's internal meter. IF THAT DIDN'T WORK There might be a setting causing excessive activity. Go to the camera's settings in the app, then "Power Manager." Make sure "Surveillance Mode" is set to "Optimal Surveillance" and not "Customized," which might have overly aggressive recording schedules that keep the camera awake and draining power faster than the charger can replenish it. HEADS UP Constantly keeping a lithium-ion battery at 100% charge while also being warm from operation can shorten its overall lifespan. Seeing it hover between 80-90% when always plugged in is normal and is actually a protective feature.

Question 4

the person detection on my dual camera is terrible, it alerts me for every shadow or light change from the window

Accepted Answer

DIAGNOSIS The camera's AI is being overwhelmed by a high-traffic area with lots of non-human movement. The default sensitivity and detection zones are probably too broad, so it's flagging everything as an event. FIX You need to train the AI by adjusting zones and sensitivity. 1) In the app, go to your camera's settings and select "Activity Zones." Draw a zone that excludes the problem area—like the window where light changes or a busy street view. 2) Next, go to "Detection Settings." Turn off "All Motion" and make sure only "Human" is selected. 3) Finally, slide the "Detection Sensitivity" down to about 3 or 4. Test it for a day. The goal is to ignore the area where shadows play, not to see everything. IF THAT DIDN'T WORK The camera's positioning might be the root cause. If it's facing a window, the backlight can silhouette everything, making it hard for the AI. Try moving the camera so the main light source (like the window) is behind it, not in front of it. This improves image contrast and makes human detection more accurate. HEADS UP The AI works best when it can see a full or mostly-full body shape. If the camera is mounted too high and just sees the tops of heads, or too low and just sees legs, its ability to identify a person drops significantly. Aim for chest-to-head height relative to where people walk.

Question 5

eufy S350 keeps going offline in the app every day or two, have to unplug it to get it back online

Accepted Answer

DIAGNOSIS This is almost always a Wi-Fi stability issue. The camera isn't handling a weak signal or interference well over long periods, causing it to drop its connection and not successfully reconnect on its own. FIX Start by checking your camera's signal strength. In the eufy Security app, go to your camera's settings, then "General," and look for "Wi-Fi Signal Strength." If it's fair or poor, you need to improve the connection. 1) Try moving your router closer, or use a Wi-Fi extester on the same 2.4GHz network. 2) More reliably, consider a powerline Ethernet adapter with a Wi-Fi access point, or move the camera closer to your router. A stronger signal is the permanent fix. IF THAT DIDN'T WORK The problem might be your router assigning a new IP address that confuses the camera. Log into your router and set up a "DHCP Reservation" or "Static IP" for the camera's MAC address (found in the eufy app under Device Info). This guarantees the camera always gets the same IP and can prevent these drop-offs. HEADS UP If you have a dual-band router, ensure the 2.4GHz and 5GHz networks have different names (SSIDs). If they have the same name, the camera can sometimes get confused after a router reboot and try to connect to the 5GHz band, which it doesn't support, causing it to fail.

Question 6

how do you clean the lens on the S350 without smearing or scratching it? the wide lens especially gets dusty

Accepted Answer

DIAGNOSIS You're right to be careful. The lenses have a multi-layer anti-reflective coating that can be damaged by rough cloths or cleaners. Dust and fingerprints are the usual suspects for blurry footage. FIX The safest method is using a camera lens cleaning kit. If you don't have one, here's the shop-teacher approved method. 1) First, use a rocket blower or a can of compressed air to gently blow loose dust off the lenses. Don't use your breath—you'll spit. 2) Get a microfiber cloth meant for glasses or screens. Never use paper towels or your shirt. 3) Lightly breathe on the lens to create a faint mist. 4) Immediately use the clean, dry microfiber cloth in a gentle circular motion from the center outward. No need to press hard. IF THAT DIDN'T WORK If there's a stubborn smudge, dampen a corner of the microfiber cloth with a tiny drop of distilled water—not tap water and absolutely not window cleaner or alcohol. Wipe gently, then immediately dry the lens with the dry part of the cloth. HEADS UP Never spray any liquid directly onto the camera lenses. Liquid can seep into the tiny seam around the lens and damage the internal electronics. Always apply the cleaner to the cloth first, not the device.

Question 7

the dual camera keeps making a loud clicking noise every few minutes, sounds like it's trying to focus over and over

Accepted Answer

DIAGNOSIS That's the sound of the PTZ (Pan-Tilt-Zoom) motor trying to recenter or recalibrate. It often gets stuck in a loop if the camera's physical movement is obstructed or if there's a software glitch telling it to go to a position it can't reach. FIX First, physically check the camera. Gently move the camera head with your hands through its full range of motion—pan left/right, tilt up/down. Feel for any snags or resistance. Once you've done that, give it a hard reset. 1) Unplug the camera from power. 2) Hold down the sync button on the back. 3) While holding the button, plug the power back in. 4) Keep holding the button for another 10 seconds until you hear the startup sound, then release. This forces a full recalibration of the motors. IF THAT DIDN'T WORK The issue might be tied to a specific Activity Zone or tracking setting. In the eufy Security app, go to the camera's settings, then to "Pan/Tilt/Zoom." Turn off "Auto-Tracking" and delete any custom Activity Zones you've created. See if the noise stops. You can try re-enabling features one by one later. HEADS UP Avoid placing the camera where curtains, blinds, or cords can drift into its field of view and trigger constant auto-tracking attempts, which can wear the motor out faster.

Question 8

my eufy S350 indoor cam just shows a solid blue light and won't connect to wifi no matter what i try

Accepted Answer

DIAGNOSIS The camera is stuck in its initial setup mode, usually because it’s not completing the handshake with your Wi-Fi network. The most common culprit is a 5GHz network or a network with special characters in the name or password. FIX First, hold the sync button on the camera for about 5 seconds until you hear a voice prompt and the light starts flashing blue. This resets the connection. Now, go into your phone's Wi-Fi settings (not the eufy app) and look for a temporary network named something like "EufyCam_XXXX". Connect to it, then return to the eufy app to finish setup. During setup, make absolutely sure you are selecting your 2.4GHz Wi-Fi network, not the 5GHz one. IF THAT DIDN'T WORK If it still fails, your router might be using a channel the camera doesn't like. Log into your router's admin page—usually through a browser—and try changing your 2.4GHz band's channel to something common like 1, 6, or 11. Save the settings, restart your router, and then try the camera setup again from scratch. HEADS UP If you have a mesh network, temporarily disable the "band steering" or "smart connect" feature that automatically switches devices between 2.4GHz and 5GHz. The camera needs a stable 2.4GHz connection to set up properly.

eufy Indoor Cam S350 Dual Camera

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