BLUETTI’s AC300 and AC500 are built the same way: an inverter “head” with no battery of its own, stacked on BLUETTI’s 3,072Wh B300-series packs. The AC500 is the bigger sibling. BLUETTI’s U.S. product page lists it at 5,000W continuous with a 10,000W surge, against the AC300’s 3,000W. In the comparison table on that same page on Oct. 17, 2026, an AC500 with two B300S packs ($3,598) cost less than an AC300 with two B300 packs ($3,999).
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The AC500 figures here come from BLUETTI’s U.S. AC500 + B300S product page, its FAQ and the AC500 user manual. The AC300 figures come from BLUETTI’s AC300 product page and the research behind our AC300 vs Apex 300 comparison. I haven’t tested either system. Runtimes I calculated myself are marked as estimates.
Shop the BLUETTI AC300 + B300 on Amazon or the AC500 + B300S on BLUETTI’s store.
Quick pick
- AC500 if you want to run big 120V loads such as a well pump, a window AC plus a microwave, or shop tools, or if you want the most solar and AC charging per head.
- AC300 if you already own B300 packs and your loads stay under 3,000W, or if you want the lighter inverter head at 47.6 lb versus 66.2 lb.
Spec comparison
| Spec | BLUETTI AC300 | BLUETTI AC500 |
|---|---|---|
| Continuous AC output | 3,000W | 5,000W (4,500W with only one B300S) |
| Surge | 6,000W | 10,000W |
| AC outlets | 6 × 120V/20A + 1 × TT-30R | 3 × 120V/20A, 1 × L14-30, 1 × TT-30, 1 × NEMA 14-50 (5,000W total) |
| DC outputs | 12V and USB outputs (see BLUETTI’s AC300 listing for ratings) | 12V/30A RV port, 24V/10A car port, 2 × USB-A 5V/3A, 2 × 18W USB-A, 2 × 100W USB-C |
| Wireless charging | 2 × 15W pads | 2 × 15W pads |
| AC charging | Up to 3,000W | 4,500W (1 × B300S) or 5,000W (2+ B300S) |
| Solar input | 2,400W total, 2 MPPT inputs, 12–150V, 12A each | 3,000W total (2 × 1,500W), 12–150V, 15A |
| Max AC + solar | 5,400W with 2+ B300 | 8,000W with 2+ B300S |
| Battery packs | B300 (3,072Wh), up to 4 | B300S (3,072Wh), up to 6; B300 works through an adapter cable |
| Max capacity per head | 12,288Wh | 18,432Wh |
| Split-phase 240V | 2 × AC300 + P030A fusion box | 2 × AC500 + P030A; up to 36,864Wh with 12 × B300S |
| UPS switchover | 20 ms | 20 ms |
| Rated cycle life | 3,500+ to 80% | 3,500+ to 80% |
| Inverter head weight | 47.6 lb | 66.2 lb (30 kg) |
| Head size | About 21 × 13 × 14 in | 20.5 × 12.8 × 14.1 in |
| App | BLUETTI app, Wi-Fi + Bluetooth | BLUETTI app, Wi-Fi + Bluetooth |
| Warranty (BLUETTI U.S.) | See BLUETTI listing | 4 years |
The five differences that matter
1. 2,000W more continuous power
The 5,000W rating is the headline. Here’s what that headroom means in practice (illustrative loads, not BLUETTI tests):
| Load mix | Approx. watts | AC300 | AC500 |
|---|---|---|---|
| Fridge + furnace blower + lights + internet | ~700W | Yes | Yes |
| Window AC + microwave | ~2,200W | Yes | Yes |
| 1,800W space heater + 1,300W hair dryer | ~3,100W | Over the limit | Yes |
| Well pump running + fridge + microwave | ~2,700W | Tight, so check the pump’s start surge | Yes, with surge to spare |
| Table saw + shop vac | ~2,800W | Tight | Yes |
The AC500’s output tops out at 4,500W with a single B300S. To get the full 5,000W you need two packs. For motor loads, check the start-up surge as well as the running watts. Our guide to surge vs running watts explains how.
2. More outlet types on the AC500
The AC300 gives you lots of ordinary 20A outlets plus a TT-30 for an RV. The AC500 trades some of those household outlets for an L14-30 and a NEMA 14-50, the high-current receptacles used for generator inlets and larger RV hookups. Its 24V/10A car port is also worth noting for 24V fridges and accessories.
3. Faster charging all around
The AC500 takes up to 5,000W from the wall (with 2+ B300S), 3,000W of solar and 8,000W combined. Estimated 0–100% times for a 6,144Wh system (two packs), ignoring taper near full:
| Source | AC300 + 2 × B300 | AC500 + 2 × B300S |
|---|---|---|
| Wall, max rate | ~2 h at 3,000W (estimate) | ~1.2 h at 5,000W (estimate) |
| Solar, max input in strong sun | ~2.6 h at 2,400W (estimate) | ~2 h at 3,000W (estimate) |
| AC + solar together | ~1.1 h at 5,400W (estimate) | ~0.8 h at 8,000W (estimate) |
A standard 120V/15A household circuit can’t supply 5,000W, so the top AC rates need a suitable circuit or a large generator. Both systems accept solar strings up to 150V. Our series vs parallel wiring guide shows how to build a long series string that stays under that limit.
4. Bigger maximum system
| Configuration | AC300 | AC500 |
|---|---|---|
| 1 pack | 3,072Wh | 3,072Wh (4,500W output) |
| 2 packs | 6,144Wh | 6,144Wh |
| Max per head | 12,288Wh (4 × B300) | 18,432Wh (6 × B300S) |
| Two heads, split phase | Up to 8 packs, 22.1kWh per BLUETTI | Up to 12 packs (36,864Wh) |
5. Weight and footprint
Both heads have nearly the same footprint, but the AC500 is about 19 lb heavier. Each B300-series pack adds its own weight, so plan for these to stay in one place, on a cart or in a utility room, rather than travel to every campsite.
What stays the same
- A 20 ms UPS switchover (BLUETTI FAQ).
- LiFePO4 packs rated for 3,500+ cycles to 80%.
- Two 15W wireless phone pads on top.
- BLUETTI app control over Wi-Fi and Bluetooth, with over-the-air firmware updates.
- A split-phase 240V option with two heads and BLUETTI’s P030A fusion box.
One detail from BLUETTI’s AC500 FAQ: with the fusion box, the system offers EPS (emergency power supply) switching rather than UPS. The AC500’s maximum is 7,200W through the P030A, or 10,000W when wired directly to a distribution box by an electrician.
AC500 UPS modes
The AC500 manual lists four UPS modes, all set in the BLUETTI app:
| Mode | BLUETTI’s description |
|---|---|
| Standard | Good for regions with an unstable grid |
| Time Control | Charges during off-peak hours to save on electricity bills |
| PV Priority | Better for regions with plenty of sunlight |
| Customized | Design your own power supply schedule |
Runtime on two packs (estimates)
Both systems hold 6,144Wh with two packs, so runtime at the same load is about the same. The AC500 just lets you run bigger loads at once. These estimates assume about 85% usable after inverter losses (~5,200Wh).
| Load | Average watts | Runtime (estimate) |
|---|---|---|
| Refrigerator | 60W average | ~3.5 days |
| Essentials: fridge, internet, lights, phone | 200W | ~26 h |
| Window AC, 8,000 BTU class | ~700W | ~7 h |
| 1,800W space heater | 1,800W | ~2.9 h |
BLUETTI’s own comparison table for 6,144Wh systems lists about 5 hours for an 8,100 BTU air conditioner and 2.7 hours for an 1,800W heater, in line with the estimates above. For whole-home sizing, see how many batteries it takes to power a house.
System prices on BLUETTI’s U.S. store (Oct. 17, 2026)
| Kit | Capacity | Price |
|---|---|---|
| AC500 + B300S | 3,072Wh | $2,299 |
| AC500 + 2 × B300S | 6,144Wh | $3,598 |
| AC500 + 3 × B300S | 9,216Wh | $5,497 |
| AC500 + B300S + Home Integration Kit (120V) | 3,072Wh | $3,158 |
| 2 × AC500 + 2 × B300S + P030A | 6,144Wh, 10,000W, 240V | $4,699 |
| AC300 + 2 × B300 (comparison table on the same page) | 6,144Wh | $3,999 |
Prices change often during sales, so check both listings before buying.
Already own B300 packs?
The AC500 manual says it connects to the B300S with the P150D expansion cable, and to the older B300 through a P150D-to-P090D cable. That gives AC300 owners an upgrade path: keep the batteries and swap the head for more output and faster charging. Check BLUETTI’s compatibility notes for mixing pack types before ordering.
FAQ
Is the AC500 just a bigger AC300?
Mostly. Both are modular inverter heads that use 3,072Wh packs. The AC500 adds 2,000W of continuous output, 600W more solar, faster AC charging, higher-current outlets and room for six packs instead of four.
Can the AC300 or AC500 run on its own?
No. Neither head has a built-in battery, so each needs at least one B300 (AC300) or B300S (AC500) pack.
Do they make 240V?
Not from a single head. Two AC300s or two AC500s with BLUETTI’s P030A fusion box create 120/240V split phase.
How fast is the UPS?
BLUETTI lists 20 ms for the AC500. The AC300 is also rated at 20 ms.
Can I use third-party solar panels?
Yes. BLUETTI’s AC500 FAQ asks for 12–150V total, 3,000W maximum and MC4 connectors. Rooftop arrays must not use microinverters.
Which is better for a home backup?
The AC500, for most homes, thanks to its higher output, faster charging and bigger maximum capacity. If your loads stay under 3,000W and you find a good deal on an AC300 kit, it does the same basic job.
Bottom line
The AC500 is the stronger system on almost every measure: 5,000W versus 3,000W, 3,000W versus 2,400W of solar and up to 18.4kWh per head. On BLUETTI’s own comparison it also cost less for the same 6,144Wh. The AC300 still makes sense if you already own B300 packs or find it discounted. For a new modular home backup build, the AC500 is the easier recommendation.