BUYER'S GUIDE • RUNTIME + CAPACITY PLANNING
BLUETTI Expansion Batteries
Expansion batteries are the fastest way to multiply your runtime without replacing your entire power station. The key is compatibility — the battery must match your power station family — and your real win is more stored energy (Wh), not higher watts. This guide covers every BLUETTI expansion battery, which station each works with, and how to pick the right one without overspending.
Quick Answer
Buy an expansion battery when your power station already runs your devices but the runtime is too short. First confirm your station's model family, then match the correct expansion battery line. If your problem is that appliances won't start at all — that's an output (watt) problem, not a runtime problem. An expansion battery won't fix that. Move to a higher class station instead.
The short version: B80/B80P for AC60/EB-series compact stations. B230/B300/B300K/B300S for mid-range AC200/AC300/AC500 systems. B500 and B500K for whole-home EP800/EP900/Apex 300 setups.
BLUETTI Expansion Batteries — Full Lineup
Every standalone expansion battery currently available from BLUETTI, with pricing, capacity, and compatible stations.
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BLUETTI B80P Expansion Battery
- Capacity806Wh
- Outputs100W USB-C, 18W USB-A, 12V/10A car port
- StandaloneYes — works as standalone power station
- Solar4 ways to recharge
- Best forCompact station users needing 2–3x more runtime
The B80P doubles or triples runtime on BLUETTI's popular compact stations. At 806Wh it can charge a phone 50–60 times or run a CPAP machine for multiple nights. Also works as a standalone power station with its own outputs.
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BLUETTI B230 Expansion Battery
- Capacity2,048Wh
- Outputs100W USB-C, 12V/10A car port, USB-A
- StandaloneYes
- ChargingSolar, car, lead-acid, AC
- Best forAC200MAX users expanding to 4,096–6,144Wh
The B230 nearly doubles the AC200MAX's onboard 2,048Wh to over 4,000Wh. Stack two for a 6,144Wh system — enough for 2–3 days of home backup covering lights, fans, a fridge, and phone charging without grid power.
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BLUETTI B300 Expansion Battery
- Capacity3,072Wh
- Outputs100W USB-C, 12V/10A car port, USB-A
- StandaloneYes — with smart MPPT solar input
- SolarSmart MPPT for faster solar recharge
- Best forAC300 system builds and serious home backup
The B300 is the workhorse of BLUETTI's expansion lineup. Required for the AC300 inverter, it can also expand the AC200MAX to 8,192Wh with two units. The smart MPPT solar input speeds up recharge — critical for extended off-grid use.
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BLUETTI B300K Expansion Battery
- Capacity2,764.8Wh
- CompatibilityNewer AC200L, AC300, AC500, Apex 300
- BatteryLiFePO4 — 3,500+ life cycles
- StackUp to 4 units on supported stations
- Best forAC500 and Apex 300 system expansion
The B300K is the newer generation expansion battery supporting BLUETTI's latest high-output stations. With 2,764.8Wh per unit and support for up to 4 stacked units, the AC300 + 4×B300K system reaches over 11,000Wh — full multi-day home backup territory.
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BLUETTI B300S Expansion Battery
- Capacity3,072Wh
- Required forAC500 inverter (won't operate without it)
- BatteryLiFePO4 — 3,500+ life cycles
- ChargingAC, solar, car
- Best forAC500 system builds needing 5,000W output
The B300S is required to operate the AC500 inverter — the AC500 cannot function without at least one B300S. Stack up to 3 for 9,216Wh of total capacity paired with the AC500's 5,000W output. The top choice for whole-home backup that doesn't compromise on power output.
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BLUETTI B500 Expansion Battery
- Capacity4,960Wh per unit
- Stack up to4 units = 19,840Wh per EP800/EP900
- Warranty10 years — industry leading
- BatteryLiFePO4
- Best forWhole-home off-grid or grid-tie setups
The B500 is BLUETTI's whole-home expansion battery, designed exclusively for EP800 and EP900 inverter systems. Each unit adds nearly 5,000Wh — one unit extends home backup by a full day. Four units with an EP800 gives nearly 20,000Wh, enough to run a home for 5–7 days on a single charge.
Check Price on BLUETTI →Expansion Battery Compatibility Chart
Match your power station to the correct expansion battery. Using the wrong battery family will result in incompatibility — these are not interchangeable.
| Your Power Station | Compatible Expansion Battery | Max Total Capacity | Notes |
|---|---|---|---|
| AC60 / AC60P | B80 / B80P | Up to 2,015Wh (station + 2× B80) | Turbo charging to 100% in 1 hour on AC60 |
| EB3A / EB55 / EB70S / AC180 | B80 / B80P (Power Bank mode) | Varies by station | B80P works in Power Bank mode with these stations |
| AC200MAX | B230 or B300 (up to 2 units) | Up to 8,192Wh with 2× B300 | Mix and match B230/B300 is supported |
| AC200P | B230 or B300 | Up to ~5,000Wh+ | Older model — confirm compatibility before purchase |
| AC200L | B230 / B300 / B300K / B210 | Up to ~6,300Wh with 2× B210 | B300K is the newer preferred expansion for AC200L |
| AC300 (inverter) | B300 or B300K (required) | Up to 12,288Wh (4× B300) or 11,059Wh (4× B300K) | AC300 CANNOT operate without at least one B300 or B300K |
| AC500 (inverter) | B300S or B300K (required) | Up to 9,216Wh (3× B300S) | AC500 CANNOT operate without at least one B300S or B300K |
| Apex 300 | B300K or B500K | Up to 8,294Wh (3× B300K) or 10,240Wh (2× B500K) | Newest flagship — B300K and B500K both supported |
| EP800 / EP900 | B500 only | Up to 19,840Wh (4× B500) | Whole-home system — B500 is purpose-built for this |
How to Pick the Right Expansion Battery
Three questions narrow your choice down to one or two options in under two minutes.
1) What station do you have?
Expansion batteries are family-specific. Start here — everything else follows from your station model.
- AC60 / compact EB series → B80P
- AC200MAX / AC200P → B230 or B300
- AC200L → B300K (preferred) or B230/B300
- AC300 → B300 or B300K (required)
- AC500 → B300S or B300K (required)
- Apex 300 → B300K or B500K
- EP800/EP900 → B500 only
2) How many hours do you need?
Match capacity to your actual daily usage — not your worst-case fantasy scenario.
- 1 extra day of phone/light backup → B80P or B230 is enough
- 2–3 days with fridge + fans → B300 or B300K
- 3–5 days full home backup → B300S × 2–3 or B500
- Extended off-grid living → B500 + EP800/EP900 system
3) Can you recharge it?
Big capacity without a recharge plan becomes a liability after day one.
- Grid power available intermittently → Any expansion works; fast AC recharge tops it off quickly
- Solar only → Size solar panels to recover at least 50% per day
- Vehicle alternator → Works for B80P and smaller expansions; impractical for B500
- No recharge plan → Buy only as much capacity as you can practically recover
Avoid These Common Expansion Battery Mistakes
Most bad expansion battery purchases come down to one of four avoidable errors.
| Mistake | What happens | Fix |
|---|---|---|
| Buying incompatible battery | The battery physically won't connect or communicate with your station. | Always verify the specific battery SKU matches your station model before ordering. |
| Expanding when you need more output | More capacity won't help if your appliance won't start — that's a wattage issue, not storage. | If your problem is "device won't run," step up to a higher watt station, not a bigger battery. |
| Buying cable/accessory listings thinking it's a battery | You receive a cable and still have the same runtime problem. | Confirm the listing title includes the battery model name and Wh rating — not just "cable" or "bundle." |
| No recharge strategy | A large battery runs out once and takes days to recharge without adequate solar or AC. | Calculate your recharge rate (solar watts × hours) against your daily usage before sizing up. |
| Stacking batteries without a plan | Overspending on capacity you can't recharge or don't realistically need. | Start with one expansion unit, test real-world runtime, then add a second if genuinely needed. |