Anker SOLIX C300 vs PowerHouse 521 — day-use entry
Two entry day-use bricks: SOLIX C300 DC (288 Wh · 300 W · USB-C-first) versus legacy PowerHouse 521 (256 Wh · 200 W AC). Feature-class honesty, not a winner crown. Prices: check current listing.
Honesty first (read this)
- No invented Wh, watts, or street prices. C300 DC: 288 Wh LiFePO4, 300 W total output, two 140 W bidirectional USB-C, 100 W solar (11-28 V), 2.8 kg / 6.17 lb, no AC outlets (Anker support / manual). 521: 256 Wh LiFePO4, 200 W AC, 2 AC outlets (anker.com); 4.34 kg, 65 W DC input (Anker support, sibling cite on 521 vs 535).
- C300 DC vs C300 (AC) naming. Anker also sells a C300 with AC outlets; QuietWatt siblings cite it at 288 Wh · 300 W · ~4.1 kg — check label for your exact card. This page compares the DC variant unless noted.
- No AC on C300 DC. If your load has a wall plug (CPAP brick, fan, lamp), the 521 or C300 AC variant fits; the DC model needs USB-C / 12 V.
- Legacy PowerHouse. 521 availability moves — confirm the current Anker card.
Nameplate figures below are from manufacturer product / support pages (checked 24 Oct 2026) — not QuietWatt lab tests or electrical / emergency-planning advice. Prices: check current listing. Estimates labelled. Feature-class, not a winner crown.
Axes that actually differ
- Wh. 288 vs 256 Wh — small gap. what size.
- Output type. 300 W total via USB-C / car socket vs 200 W AC inverter. pure sine wave.
- Refill. C300 DC up to 280 W via dual 140 W USB-C (mfr); 521 adapter / 60 W USB-C class. charging speed.
- Solar. 100 W vs 65 W max (mfr). MPPT vs PWM.
- Weight. 2.8 kg vs 4.34 kg (mfr) — stairs / lightest.
Side-by-side (manufacturer nameplate)
Not a sponsored ranking. Confirm the current listing / label for your region SKU.
| Axis | SOLIX C300 DC | PowerHouse 521 |
|---|---|---|
| Capacity | 288 Wh LiFePO4 (mfr) | 256 Wh LiFePO4 (mfr) |
| Output | 300 W total, USB-C / USB-A / car; no AC (mfr) | 200 W AC, 2 outlets (mfr) |
| USB-C | 2× 140 W bidirectional + 100 W + 15 W (mfr) | 1 USB-C — check listing for watts |
| Solar input | 100 W max, 11-28 V (mfr) | 65 W max DC (mfr) |
| Weight | 2.8 kg / 6.17 lb (mfr) | 4.34 kg / 9.57 lb (mfr) |
| Sibling ladders | 535 vs C300 · C300 vs C800 | 521 vs 535 · 521 vs 757 |
Models on this page (confirm listing)
Approx. USD: check current listing — QuietWatt does not quote street prices here.
| Model | Wh · notes | Why it lands here | Approx. USD |
|---|---|---|---|
| Anker SOLIX C300 DC 288 Wh DC | 288 Wh · 300 W · 2.8 kg (mfr) | Laptop / phone / camera day bag, fast USB-C refill. | Check current listing |
| Anker 521 PowerHouse 256 Wh AC | 256 Wh · 200 W AC · 4.34 kg (mfr) | When a small AC plug is the job. CPAP overnight. | Check current listing |
When each one wins
C300 DC wins
521 wins
535 / C800 wins
Surge / start / continuous: motor loads can trip small inverters — see peak vs continuous · best camping · what size.
Where to buy (affiliate placeholders)
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Placeholder anchors: #aff-ecoflow, #aff-bluetti,
#aff-anker, #aff-jackery, #aff-amazon.