B500K for Apex 300 vs EcoFlow DELTA Pro 3 Smart Extra Battery (Recommended Accessory)
Compatibility note: expansion batteries only attach to their own brand's stations — this one pairs with BLUETTI systems, the other with EcoFlow's. Read this as a value and longevity comparison (which ecosystem is cheaper to expand), not a choice between interchangeable parts.
- Price today: EcoFlow is $300 cheaper ($1,699 vs $1,999).
- Cost per Wh: $0.39 vs $0.41 — B500K for Apex 300 gives you more battery per dollar today.
| B500K for Apex 300 | EcoFlow DELTA Pro 3 Smart Extra Battery (Recommended Accessory) | |
|---|---|---|
| Price today | $1,999 | $1,699 |
| Deal status | Tracking since 6d | Tracking since 6d |
| Capacity | 5120Wh | 4096Wh |
| $/Wh | $0.39 | $0.41 |
| Chemistry | LFP | LFP |
| Rated cycles | — | 4,000 |
| Output | — | — |
| Solar input | — | — |
| Weight | — | — |
| Expandable | — | — |
| Standalone use | No — link port only | No — link port only |
| Recharge without station | No — only through the station | No — only through the station |
| All-time low | $1,999 (2026-07-07) | $1,699 (2026-07-07) |
| View at BLUETTI — $1,999 | View at EcoFlow — $1,699 |
Full tech-spec comparison all specs
| B500K for Apex 300 | EcoFlow DELTA Pro 3 Smart... | |
|---|---|---|
| Battery | ||
| Chemistry | LFP | LFP |
| Capacity | 5,120Wh | 4,096Wh |
| Rated cycles | 4,000+ cycles to 80% original capacity (confirms held value) | 4,000 |
| Expandable | Yes | Yes |
| Max expanded | 100,000 Wh (confirms held value) | 12,000Wh |
| Output | ||
| AC outlets | 0 (link port only) | 0 (link port only) |
| USB-C ports | 0 (link port only) | 0 (link port only) |
| USB-A ports | 0 (link port only) | 0 (link port only) |
| 12V / car output | 0 (link port only) | 0 (link port only) |
| Input & charging | ||
| AC input | None — recharges via the station only | None — recharges via the station only |
| Solar (PV) input | None — pack has no direct solar input (600W value belongs to the host station) | None — recharges via the station only |
| Car input | None — recharges via the station only | None — recharges via the station only |
| General & physical | ||
| Weight | 99.21 lbs (45 kg) | 72.8 |
| Warranty | 4 years | 5 years |
Also published by B500K for Apex 300
| Solar voltage / current | 13–50V · 20A |
|---|---|
| Dimensions | 0.43x6.65 x2.74 in |
| Operating temperature | 4°F to 140°F |
| Noise level | 50 dB |
| Connectivity | Wi-Fi · Bluetooth |
Like-for-like specs both brands publish are shown first (✓ = better value); each brand's remaining published specs follow. Core figures are editorially verified; the rest come from each manufacturer's tech specs.
Price history — B500K for Apex 300
Price history — EcoFlow DELTA Pro 3 Smart Extra Battery...
Prices recorded daily from the official BLUETTI and EcoFlow stores. Deal statuses compare each product to its own 90-day history — methodology.