B300K for AC500 vs EcoFlow DELTA 3 Max Plus (2048Wh) Smart Extra Battery
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 $600 cheaper ($899 vs $1,499).
- Cost per Wh: $0.54 vs $0.44 — EcoFlow DELTA 3 Max Plus (2048Wh)... gives you more battery per dollar today.
| B300K for AC500 | EcoFlow DELTA 3 Max Plus (2048Wh) Smart Extra Battery | |
|---|---|---|
| Price today | $1,499 | $899 |
| Deal status | Above typical | Typical price |
| Capacity | 2765Wh | 2048Wh |
| $/Wh | $0.54 | $0.44 |
| Chemistry | LFP | LFP |
| Rated cycles | 6,000 | — |
| Output | — | — |
| Solar input | — | — |
| Weight | 65 lbs | 35.3 lbs |
| Expandable | to 33177.6Wh | — |
| Standalone use | Yes — USB-A 12W | No — link port only |
| Recharge without station | No — only through the station | No — only through the station |
| All-time low | $1,249 (2026-07-07) | $849 (2026-07-07) |
| View at BLUETTI — $1,499 | View at EcoFlow — $899 |
Full tech-spec comparison all specs
| B300K for AC500 | EcoFlow DELTA 3 Max Plus... | |
|---|---|---|
| Battery | ||
| Chemistry | LFP | LFP |
| Capacity | 2,765Wh | 2,048Wh |
| 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 | 1× 12W | 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 — recharges via the station only | None — recharges via the station only |
| Car input | None — recharges via the station only | None — recharges via the station only |
| General & physical | ||
| Weight | 65.0 | 35.3 lbs |
| Warranty | 4 years | 5 years |
Also published by B300K for AC500
| Rated cycles | 6000 |
|---|---|
| Expandable | Yes |
| Max expanded | 33,177.6Wh |
Also published by EcoFlow DELTA 3 Max Plus...
| Dimensions | 494*239*196mm |
|---|---|
| Operating temperature | 14°F to 113°F |
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 — B300K for AC500
Price history — EcoFlow DELTA 3 Max Plus (2048Wh) 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.