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B500K for Apex 300 vs EcoFlow DELTA Pro Ultra Series 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.

B500K for Apex 300 EcoFlow DELTA Pro Ultra Series Smart Extra Battery (Recommended Accessory)
Price today$1,999$2,099
Deal statusTracking since 6dTracking since 6d
Capacity5120Wh6000Wh
$/Wh$0.39$0.35
ChemistryLFP
Rated cycles
Output
Solar input
Weight
Expandable
Standalone useNo — link port only
Recharge without stationNo — only through the station
All-time low$1,999 (2026-07-07)$2,099 (2026-07-07)
View at BLUETTI — $1,999 View at EcoFlow — $2,099
Full tech-spec comparison all specs
B500K for Apex 300 EcoFlow DELTA Pro Ultra Series...
Battery
Chemistry LFP LFP
Capacity 5,120Wh 6,000Wh
Rated cycles 4,000+ cycles to 80% original capacity (confirms held value) 3500
Expandable Yes Yes
Max expanded 100,000 Wh (confirms held value) 90000
General & physical
Weight 99.21 lbs (45 kg) 111.8
Warranty 4 years 5 years

Also published by B500K for Apex 300

AC outlets0 (link port only)
USB-C ports0 (link port only)
USB-A ports0 (link port only)
12V / car output0 (link port only)
AC inputNone — recharges via the station only
Solar (PV) inputNone — pack has no direct solar input (600W value belongs to the host station)
Solar voltage / current13–50V · 20A
Car inputNone — recharges via the station only
Dimensions0.43x6.65 x2.74 in
Operating temperature4°F to 140°F
Noise level50 dB
ConnectivityWi-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 for B500K for Apex 300$1,9992026-07-072026-07-12

Price history — EcoFlow DELTA Pro Ultra Series Smart Extra...

Price history for EcoFlow DELTA Pro Ultra Series Smart Extra Battery (Recommended Accessory)$2,0992026-07-072026-07-12

Prices recorded daily from the official BLUETTI and EcoFlow stores. Deal statuses compare each product to its own 90-day history — methodology.