Go Power! ASW-1200-12-TS
#28 in 1,100 to 2,000 WFull review
For RVs that already have a converter or solar charging and want an inverter with a built-in transfer switch.
Amazon $398.74$398.74
The Go Power! ASW-1200-12-TS rates 3.1 among 1,100 to 2,000 W 12V inverters; the Go Power! GP-ISW1000 rates 2.5 among up to 1,000 W ones. The Go Power! GP-ISW1000 costs $30.84 less ($367.90 vs $398.74).
Go Power! GP-ISW1000
#25 in Up to 1,000 WFull review
For vans and small RVs that run a small microwave or coffee maker and want low idle draw.
Amazon $367.90$367.90
Prices were last checked October 24, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Scores side by side
These two sit in different size classes (1,100 to 2,000 W and up to 1,000 W), and each is scored against the reference points for its own class, so a rating says how well each does among its own size peers. How we rank explains each factor.
| Factor weight | Go Power! ASW-1200-12-TS | Go Power! GP-ISW1000 |
|---|---|---|
| Overall rating | 3.1/5 | 2.5/5 |
| Value 30% | 33 $0.33 per continuous watt | 48 $0.37 per continuous watt |
| Idle draw 15% | 13 1.8 A idle (about 21.6 W) with nothing plugged in | 0 1.5 A idle (about 18 W) with nothing plugged in |
| Safety listing 15% | 100 Certified UL 458; cULus certified | 0 no UL 458 or UL 1741 listing stated |
| Warranty 15% | 25 2-year warranty | 25 2-year warranty |
| Features 15% | 52 optional remote, transfer switch, hardwire terminal; no app | 12 optional remote; no app |
| Efficiency 10% | 67 91% peak efficiency (maker rating) | 78 92% peak efficiency (maker rating) |
Specifications
| Go Power! ASW-1200-12-TS | Go Power! GP-ISW1000 | |
|---|---|---|
| Output | ||
| Type | Pure sine wave inverter | Pure sine wave inverter |
| Continuous power | 1,200 W | 1,000 W |
| Surge power | 2,400 W for 3 s | 1,750 W |
| DC input range | 10 to 16.5 V | 10.5 to 16.5 V |
| Idle draw | 1.8 A (21.6 W) | 1.5 A (18 W) |
| Power-saving draw | 0.1 A | 0.1 A |
| Peak efficiency | 91% | 92% |
| Connections | ||
| AC outlets | 0 | 2 |
| GFCI outlets | No | Yes |
| Hardwire terminal | Yes | No |
| USB ports | None | None |
| Transfer switch | Yes | No |
| Parallel units | No | No |
| Control and build | ||
| Remote | Optional extra | Optional extra |
| App | No | No |
| Display | No | No |
| Safety listing | Certified UL 458; cULus certified | No |
| Cooling | - | load-controlled fan |
| Dimensions | 227 x 86 x 346 mm (8.94 x 3.39 x 13.62 in) | 372 x 200 x 83 mm (14.65 x 7.87 x 3.27 in) |
| Weight | 7.5 lb | 7.2 lb |
| Warranty | 2 years | 2 years |