First Alert SMI100-AC
Hardwire Interconnect Smoke Alarm with Battery Backup, 1-Pack
Price as of 2026-08-12. Check Amazon for the current price.
Quick Decision
Is This Right For You?
- •Those who want a top-rated option — in the top 1% of Smoke Detectors by rating
📊 Based on data analysis of 6 products in this category.
Mubboo Score: A
How we calculate the Mubboo Score
Quality (45%): customer rating, normalized to a 10-point scale
Popularity (35%): review volume vs the category leader, log-scaled
Value (20%): price position vs other Smoke Detectors
Computed from live Amazon rating, review count, and price across 6 Smoke Detectors available to US consumers · last refreshed 2026-08-12.
How It Compares
This Product First Alert SMI100-AC | Most Popular First Alert Smoke Alarm | Best Rated Kidde Smoke Detector | Best Value First Alert Smoke Alarm | |
|---|---|---|---|---|
| Price | $19.49 | $24.59 | $21.77 | $16.99 |
| Rating | 4.6/5 | 4.4/5 | 4.6/5 | 4.6/5 |
| Reviews | 2,162 | 8,237 | 7,603 | 4,421 |
| Mubboo Score | A | A- | A | A+ |
Quick Specs
- Alarm
- Smoke Alarm
- Color
- White
- Style
- Precision Detection
- Unit Count
- 1.0 Count
- Item Weight
- 0.6 Pounds
- Sensor Type
- Ionization
- Manufacturer
- Resideo
- Model Number
- SMI100-AC
What buyers say about Smoke Detectors
Themes from buyer reviews across this category — not review data for this specific model.
Test units upon arrival, as included batteries may be dead or drain quickly. Verify activation tab functions and note that sealed-battery models may not interconnect with other alarms.
- Ease of Installation
- Good Value
- Reliable Performance / No False Alarms
- Compatibility with Existing Mounts
- Long Battery Life / No Battery Changes
- Pre-installed Battery Drains Quickly
- Dead on Arrival / Activation Issues
- Flimsy Build Quality
- Confusing Instructions
Expert Picks in Smoke Detectors
- X-Sense SCO7-WX — Best overall value combo
- First Alert SMICO100 — Best battery life
- First Alert SMCO100V-AC — Best hardwired option
- Google Nest Protect — Best overall smart detector
- First Alert Onelink Safe and Sound — Large homes and Apple ecosystem
- Kidde RemoteLync Monitor — Best battery life and vacation homes
Category recommendations from independent expert publications. Source links in References.
Related Video Reviews
- 📹 There are two types of smoke alarm. One of 'em ain't so good. — Technology Connections
- 📹 Using the Google Nest Protect Smart Smoke Alarm — Tech With Brett
Key Features
- ✦First Alert's Precision Detection advanced sensing technology complies with new industry standards to reduce cooking nuisance alarms and provides early warning in the event of a ho…
- ✦Through early warning interconnect, when one alarm sounds, all compatible alarms will sound
- ✦Battery backup provides continuous protection during power outages
- ✦Alarm indicator visually identifies the unit that initiated the alarm
- ✦Quick Connect Plug included allows for easy installation with no need to rewire
Source: product listing on Amazon.
About First Alert
- 10 products in our database
- Average rating: 4.7/5 across all products
- Price range: $11.98 – $42.98
- Categories: Carbon Monoxide Detectors, Fire Extinguishers, Smoke Detectors
If not the SMI100-AC, consider these
Featured in Our Reviews
Bottom Line
First Alert SMI100-AC earns Mubboo Score A. Priced at $19 — a mid-range option, below the category average of $31. Rated 4.6/5 from 2,162+ reviews. Strong buy if: those who want a top-rated option.
Frequently Asked Questions
Is the First Alert SMI100-AC worth buying in 2026?
It earns a Mubboo Score of A, with a 4.6/5 rating from 2,162 reviews — better than 100% of Smoke Detectors we track.
How much does the First Alert SMI100-AC cost?
It is currently $19.49 — mid-tier pricing for Smoke Detectors.
How does the SMI100-AC compare to other Smoke Detectors?
The category's most-reviewed alternative is the First Alert Smoke Alarm (4.4/5, 8,237 reviews, $24.59). The SMI100-AC carries a Mubboo Score of A vs A-.
Sources & References
- View on Amazon →
- safewise review →
- smarthomeexplorer review →
- wirecutter-via-engineerfix review →
- Browse all Smoke Detectors on Mubboo →
Products available through US retailers. Prices in USD. Sales tax varies by state and is not included.
Mubboo may earn a commission on purchases made through affiliate links. This does not affect our Mubboo Score, product rankings, or editorial judgments. Prices are accurate as of the last sync (2026-08-12) and may change.