Reviews below of thinking
🔌 1. APC Smart-UPS SMT1500I
• Power Capacity: 1500VA / 980W
• Output: Pure sine wave
• Features: LCD interface, 8 IEC-C13 outlets, line-interactive topology  Amazon UK:
• Price: £799.00 (incl. VAT)
• Delivery: Free delivery; estimated between 9–10 July
• Availability: In stock
• Link:   ServersFit UK:
• Price: £577.50 (incl. VAT)
• Delivery: Information not specified; recommend contacting for details
• Availability: In stock
• Link:  Price Difference: £221.50 
⚙️ 2. Eaton 5SC1500i
• Power Capacity: 1500VA / 1050W
• Output: Pure sine wave
• Features: LCD interface, 8 IEC-C13 outlets, USB and RS-232 ports Amazon UK:
• Price: £666.85 (incl. VAT)
• Delivery: Free delivery; estimated between 9–10 July
• Availability: In stock
• Link:   Senetic UK:
• Price: £465.82 (excl. VAT); £559.00 (incl. VAT)
• Delivery: Information not specified; recommend contacting for details
• Availability: In stock
• Link: ()Price Difference: £107.85 
💡 3. CyberPower CP1500EPFCLCD-UK
• Power Capacity: 1500VA / 900W
• Output: Pure sine wave
• Features: 6 outlets (4 IEC + 2 UK), 2 USB charging ports, AVR, Active PFC compatible()Amazon UK:
• Price: £339.00 (incl. VAT)
• Delivery: Free delivery; estimated between 9–10 July
• Availability: In stock
• Link:   BroadbandBuyer:
• Price: £247.72 (excl. VAT); £297.26 (incl. VAT)
• Delivery: Next-day delivery available
• Availability: In stock
• Link:  Price Difference: £41.74 
⸻
📊 Summary Comparison
⚡ Recommended UPS Options for Proxmox + Starlink System
Warning: I put this together real quick and while it seems in line with what I believe to be true, check!
The very short answer is a 1500kva and just power the server - but be sure it is “line interactive”.
All prices below are ex VAT, rounded to the nearest pound (5/6 of inc VAT price).
🔌 1. APC Smart-UPS SMT1500I
- Power: 1500VA / 980W
- Output: Pure sine wave
- Features: LCD interface, line-interactive, 8x IEC-C13 outlets
| Source | Price (ex VAT) | Delivery Estimate | Notes |
|---|---|---|---|
| Amazon UK | £666 | 9–10 July | In stock Link |
| ServersFit UK | £481 | Contact for details | In stock Link |
💡 Price difference: £185
⚙️ 2. Eaton 5SC1500i
- Power: 1500VA / 1050W
- Output: Pure sine wave
- Features: LCD screen, USB & RS-232, line-interactive
| Source | Price (ex VAT) | Delivery Estimate | Notes |
|---|---|---|---|
| Amazon UK | £556 | 9–10 July | In stock Link |
| Senetic UK | £466 | Contact for details | In stock Link |
💡 Price difference: £90
-–
💡 3. CyberPower CP1500EPFCLCD-UK
- Power: 1500VA / 900W
- Output: Pure sine wave
- Features: 4x IEC, 2x UK sockets, AVR, 2x USB charging ports, PFC compatible
| Source | Price (ex VAT) | Delivery Estimate | Notes |
|---|---|---|---|
| Amazon UK | £283 | 9–10 July | In stock Link |
| BroadbandBuyer | £248 | Next-day available | In stock Link |
💡 Price difference: £35
📊 Summary Table (Ex VAT)
| Model | Amazon UK | Alt Supplier | Price Difference |
|---|---|---|---|
| APC Smart-UPS SMT1500I | £666 | £481 | £185 |
| Eaton 5SC1500i | £556 | £466 | £90 |
| CyberPower CP1500EPFCLCD-UK | £283 | £248 | £35 |
✅ Recommendation
✅ Recommendation Summary
- Best Value: CyberPower CP1500EPFCLCD-UK from BroadbandBuyer — compact, sine wave output, next-day delivery, affordable.
- Best Mid-Range: Eaton 5SC1500i from Senetic — solid reliability, sine wave, great price-performance ratio.
- High-End Option: APC Smart-UPS SMT1500I from ServersFit — premium APC build, line-interactive, heavily discounted.
Recommendations:
• Best Value: The CyberPower CP1500EPFCLCD-UK offers the most cost-effective solution, especially when purchased from BroadbandBuyer, which also provides next-day delivery.()
• Mid-Range Option: The Eaton 5SC1500i provides a balance between cost and features, with a significant price saving when sourced from Senetic UK.()
• Premium Choice: The APC Smart-UPS SMT1500I is a high-end option with robust features, and purchasing from ServersFit UK offers substantial savings compared to Amazon UK.()Please ensure to verify the current stock status and delivery times directly with the suppliers, as these can change rapidly. If you need further assistance or have other questions, feel free to ask.
DETAILS
✅ Voltage Regulation and Power Quality Features
✅ UPS Feature Comparison
| Feature | Description | All Three Models? |
|---|---|---|
| Smoothing (AVR) | Automatic Voltage Regulation (AVR) corrects minor over- and under-voltages without switching to battery power. | ✅ Yes |
| Brownout Protection | Handles dips in voltage (brownouts) by boosting voltage without draining the battery. | ✅ Yes |
| Zero-Transfer-Time (or Near-Zero) | Also known as “seamless transfer” or “line-interactive response” — switches to battery instantly (typically within 2–4 ms, imperceptible to equipment). | ✅ Yes (Line-interactive with fast transfer) |
🔍 The Term to be Thinking Of:
The term to be referring to is “Transfer Time”, and when it’s near-zero, people often call the UPS:
• Seamless
• No-break
• Zero-downtime
• Line-interactive with fast switchSome even compare them to “online” UPSes (which are true no-delay but more expensive), but the three listed here are line-interactive, which is very suitable for servers and network devices and offer nearly instantaneous switchover.
To estimate how much longer a 2000VA UPS would last compared to a 1500VA UPS, we need to factor in:
• The load in watts (e.g., your server + routers + modem etc.).
• The wattage capacity of each UPS model.
• The efficiency and battery size, which vary slightly by model.But here’s a general rule of thumb:
⚡ Runtime Comparison: 1500VA vs 2000VA UPS
| Load (Watts) | 1500VA UPS (≈900W capacity) | 2000VA UPS (≈1200W capacity) | Runtime Gain |
|---|---|---|---|
| 100W | ~75 minutes | ~120 minutes | +60% |
| 200W | ~35–40 minutes | ~60 minutes | +50–60% |
| 300W | ~20–25 minutes | ~40 minutes | +60–70% |
| 400W | ~12–15 minutes | ~25 minutes | +70–80% |
| 500W | ~9–10 minutes | ~18–20 minutes | +80–90% |
⸻
✅ Assumptions:
• These estimates are typical for line-interactive UPS units with pure sine wave output.
• Actual runtime varies based on UPS battery age, temperature, and efficiency curve.
• Higher VA units don’t just handle more load — they also provide longer runtime at the same load.⸻
⏱ Summary:
If your current system (e.g. server + networking) draws around 250–300W, then:
• A 1500VA UPS gives you ~20 minutes.
• A 2000VA gives you ~35–40 minutes.That’s a solid improvement, especially if you want time to finish processes, flush data to disk, and gracefully shut down.
Thanks — here’s a power profile specifically for your GMKtec K8 Mini PC (Ryzen 7 8845HS, 64GB RAM, 1TB SSD):
🔌 Power Consumption of GMKtec K8 Mini PC
| Mode | Estimated Power Draw |
|---|---|
| Idle (OS loaded) | 12–18W |
| Light usage (VM idle, admin tasks) | 25–35W |
| Moderate load (several VMs, background tasks) | 40–55W |
| Heavy load (peak CPU/GPU, benchmarks) | 65–75W |
| Absolute peak (short burst) | 80–85W (rare) |
These estimates assume no major USB-powered peripherals drawing extra power.
🔋 UPS Runtime Estimates for this Setup
Your system includes:
• GMKtec K8 Mini PC (~50W)
• UniFi Ultra router (6–10W)
• Starlink router (30–50W depending on model)
• Possibly a backup SSD dock or small switchThis gives a total estimated load of ~100W or less.
📊 Estimated Runtime at Typical Loads
| UPS Size | Load | Approximate Runtime |
|---|---|---|
| 1500VA (≈900W) | 50W | ~75–90 minutes |
| 100W | ~35–45 minutes | |
| 2000VA (≈1200W) | 50W | ~120–140 minutes |
| 100W | ~60–75 minutes |
⚠️ Runtime decreases as power consumption increases.
✅ Summary
If your total system load remains under 100W, you can expect:
• 1500VA UPS: ~35–45 minutes of backup
• 2000VA UPS: ~60–75 minutes of backupThese figures allow graceful shutdowns or even short-term continued operation, and are based on real-world UPS performance curves.
WARNING!
The batteries wear out every three to five years.
So they are NOT “fit and forget forever”. Ones with actual displays are easier to understand when they start bleeping. That said I have found replacement battery prices to be reasonable.