Magnum MS4048-L
For a 48 V RV, cabin or backup system that needs a rugged, listed 120 V inverter-charger with big surge.
ResSupply $2,026 A1 Solar Store $2,531.49$2,026
The Magnum MS4048-L rates 3.8 among 120V inverter-chargers 48V inverters; the Cotek SP-4000-148 rates 2.3 among over 1,500 W ones. The Cotek SP-4000-148 costs $710 less ($1,316 vs $2,026).
Cotek SP-4000-148
#17 in Over 1,500 WFull review
A 4,000 W hardwired inverter for a 48 V off-grid panel feed, with good efficiency but a short warranty.
Amazon $1,316$1,316
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 (120V inverter-chargers and over 1,500 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 | Magnum MS4048-L | Cotek SP-4000-148 |
|---|---|---|
| Overall rating | 3.8/5 | 2.3/5 |
| Value 30% | 45 $0.51 per continuous watt | 33 $0.33 per continuous watt |
| Idle draw 15% | 79 25 W idle with nothing plugged in | 5 48 W idle with nothing plugged in |
| Safety listing 15% | 100 ETL listed to UL/cUL 458 and CSA C22.2 No. 107.1-01; UL 1741 certificate (ATM) | 0 no UL 458 or UL 1741 listing stated |
| Warranty 15% | 50 3-year warranty | 25 2-year warranty |
| Features 15% | 50 optional remote, app add-on, lithium charge profile, hardwire terminal | 20 optional remote, hardwire terminal; no app |
| Efficiency 10% | 100 94% peak efficiency (maker rating) | 67 91% peak efficiency (maker rating) |
Specifications
| Magnum MS4048-L | Cotek SP-4000-148 | |
|---|---|---|
| Output | ||
| Type | Pure sine wave inverter-charger | Pure sine wave inverter |
| AC output | 120 V | 120 V |
| Continuous power | 4,000 W | 4,000 W |
| Surge power | 8,500 W for 5 s | 8,000 W for 1 s |
| DC input range | 36 to 67.6 V | 42 to 66 V |
| Idle draw | 25 W (0.5 A at 48 V) | 48 W (1 A at 48 V) |
| Power-saving draw | 8 W | 4.8 W |
| Peak efficiency | 94% | 91% |
| Connections | ||
| AC outlets | 0 | 0 |
| GFCI outlets | No | No |
| Hardwire terminal | Yes | Yes |
| USB ports | None | None |
| Transfer switch | Yes | No |
| Pass-through rating | 30 A | - |
| Charger | 60 A | - |
| Lithium charge profile | Yes | - |
| Parallel units | No | No |
| Control and build | ||
| Remote | Optional extra | Optional extra |
| App | Optional add-on | No |
| Display | No | No |
| Safety listing | ETL listed to UL/cUL 458 and CSA C22.2 No. 107.1-01; UL 1741 certificate (ATM) | No |
| Design | Low-frequency (transformer) | - |
| Cooling | fan | load-controlled fan |
| Dimensions | 13.75 x 12.65 x 8 in (349 x 321 x 203 mm) | 255 x 158 x 462 mm (10.0 x 6.2 x 18.2 in) |
| Weight | 55 lb | 22 lb |
| Warranty | 3 years | 2 years |