eufy Video Doorbell E340: problems, parts and running costs

Checked: 2026-10-16

Summary

The E340 is a dual-camera, battery-or-hardwired doorbell: a 2K front camera for visitors plus a 1600 x 1200 downward camera that watches the package drop zone, with free local storage and no subscription. The two things that go wrong most are battery life — owners report 3 weeks to about 90 days against a 6-month claim, including hardwired units that still drain — and latency: Expert Reviews measured 11.5 s from event to live view. Running cost is $0 if you keep storage on the device’s 8 GB; the optional extras are a spare battery pack at $29.99 and an Add-On Chime at $39.99 (eufy US, 2026-10). It is a good buy at or below $120, and reasonable at $149.99 (eufy US and Best Buy, 2026-10) if you get deliveries; above $160 faster single-camera doorbells are the better money.

Common problems and fixes

Battery drains far faster than the 6-month claim — the most common complaint on r/EufyCam: about 90 days in balanced surveillance mode, 28 days after dropping sensitivity to minimum and switching illumination off, 3 weeks in another household, and one unit going from 60 % to a low-battery shutdown overnight, draining 21 % in 6 hours [6][7][8]. Plan on charging every 1-3 months and buy the spare pack so one battery charges while the other is in the doorbell. eufy does not acknowledge a defect; the 12-month hardware warranty covers a failed unit, but these threads establish a pattern, not a failure rate [19].
Hardwired units still drain — an owner with a wired install and the green plug icon went from 50 % to a lost connection within three hours [9]; another saw a wired unit drop below 33 % in under 24 h [10]. eufy’s own FAQ says the battery must stay installed even in wired mode [1][16], which matches those reports. Workaround: none reported; verify the transformer first — eufy’s pages conflict (8-24 V at above 10 VA on the US page, 16-24 V at 10 VA on the spec sheet, 16-24 V at 30 VA or above in Ireland) [1][2][16], and one owner was told by the app to fit 16-24 V, 30 VA [11].
App rejects the existing transformer — one owner was told by the app to replace the transformer with a 16-24 V, 30 VA unit, and reported a wavy screen on the front camera after battery installation [11]. Check your transformer against eufy’s figures before ordering [1][2][16].
Motion detected but visits and packages not recorded — one owner reported the doorbell detecting motion without recording visits and packages [14]. Related maintenance: re-check the mounting bracket every few months, because wind and button presses loosen screws and a wobbly camera causes false motion alerts [21].

Parts and consumables

Rechargeable Battery Pack with USB-C — $29.99 (eufy US, 2026-10) [1]; the only user-serviceable wear item, removable so a spare can charge outside the doorbell; full charge takes about 5 hours [1][17]; replacement interval is not reported in the sources.
Add-On Chime — $39.99 (eufy US, 2026-10) [1]; the US base package appears to ship without a chime [1][17], so budget this if you want audible indoor ringing; the chime has a microSD slot for clip storage [4]. Not a consumable; no replacement interval applies.

Yearly running cost

$0 for a typical owner who keeps storage local: 8 GB on-device eMMC with no subscription, and eufy’s FAQ says 8 GB holds about 90 days at an average of 30 recordings of 20 s per day — a modelled figure, not a guarantee [1]; Best Buy’s copy says about 60 days [15]. One-time optional costs: spare battery $29.99 (eufy US, 2026-10) [1], Add-On Chime $39.99 (eufy US, 2026-10) [1], a microSD card (price not reported) [15], and the E340 + HomeBase S380 bundle at $219.99 (eufy US, 2026-10) for up to 16 TB and Cross Camera Tracking [18][3][5]. No electricity cost is reported in the sources.

When it is a good buy

eufy US lists the base doorbell at $149.99, Best Buy the black model (T821411C) at $149.99, and Dell the same part at $169.99 (all 2026-10) [1][15][20]. PCMag reviewed it at a $179.99 launch price and Expert Reviews at £180 with frequent discounts to £150 [3][4].
At or below $120: strong value — the dual-camera package with free local storage has no mainstream equivalent at that money [4][5].
Above $160: weak — single-camera doorbells with measured lower latency exist, such as the Ring Video Doorbell Plus at 2.4 s total [4]; above $180 only the HomeBase S380 route justifies it (16 TB, Cross Camera Tracking) [3][5].
If you do not receive packages, most of what you pay for is a camera pointed at your own doorstep [4][5].