1 / 8Hover to zoom · click to enlarge4000W 12V Low Frequency Pure Sine Wave Inverter Charger
Ships from SunGoldPower's U.S. warehouse
- Free shipping, no minimumTo the lower 48 states and Washington, D.C.
- Authorized SunGoldPower dealerFull manufacturer warranty and support.
- 1-year warrantyBacked by SunGoldPower.
- 30-day returnsOn new, unused items.
Shipping & handling
- Orders are processed within 1–3 business days.
- Parcel items typically arrive 3–7 business days after shipping. Freight items (panels, batteries, inverters and kits) typically arrive 5–14 business days after shipping.
- Rich Solar and SunGoldPower products ship free to the lower 48 states and Washington, D.C., with no minimum. Lensun shipping is based on weight and shown at checkout.
- Freight deliveries need an appointment and a signature, and are delivered curbside.
Returns & refunds
Request a return within 30 days of delivery. Items must be new, unused, not installed, and in their original packaging.
- Contact us first for a Return Merchandise Authorization (RMA). Returns sent without one are refused.
- For a change-of-mind return, you pay return shipping and a 15% restocking fee is deducted from your refund.
- Damaged on arrival? Report it within 3 business days of delivery and we arrange a replacement or full refund.
Warranty
SunGoldPower's LFP series manual lists a 1-year standard warranty for these inverter chargers, starting on the date of purchase. Coverage is for the original buyer and excludes misuse, modification and unauthorized repair.
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A 4000W, 12V low-frequency inverter charger with a 120A charger
The LFP4K12V120VSG is SunGoldPower's 4000W, 12V low-frequency pure sine wave inverter charger. It combines an inverter, a 120A three-step battery charger and an automatic transfer switch in one unit, with a surge rating of 12,000W for 20 seconds.
It takes 120VAC from the grid or a generator and supplies 120VAC at 50 or 60Hz. AC or battery priority, automatic generator start and a 0-100% adjustable charge current suit RVs, off-grid cabins and backup systems. An LCD remote control and a battery temperature sensor cable come in the box.
Low-frequency design with 300% surge
A transformer-based, low-frequency design rated for 12,000W of surge for 20 seconds, for tools and loads with motors.
- 4000W continuous pure sine wave output
- Starts electric motors up to 4HP
Built-in 120A battery charger
A 3-step smart charger with charge current adjustable from 0 to 100%, or switched off.
- 9 battery type settings, including LiFePO4
- Battery temperature sensor (BTS) cable included
AC or battery priority with auto transfer
A built-in transfer switch moves loads between AC input and battery in 10 ms; AC priority is the default and battery priority is set with SW5.
- 120VAC input from grid or generator
- 120VAC output at 50 or 60Hz (SW4)
Automatic generator start
The inverter can start a generator when battery voltage runs low and turn it off once charging is finished.
- Works with generators that have an auto-start function
Remote control, GFCI outlet and DIP switches
An LCD remote control with cable is included, and DIP switches set output frequency, low-battery trip and AC/battery priority.
- GFCI outlet on the unit
- Idle draw 45W, or 18W in power-saver mode
Specs, images and product claims on this page come from SunGoldPower's LFP4K12V120VSG product page, spec sheet and LFP series manual. Last checked Oct 30, 2026.
Specifications
From SunGoldPower's published specifications for model LFP4K12V120VSG.
Inverter output
| Continuous output power | 4,000W |
|---|---|
| Surge rating | 12,000W (20 seconds) |
| Motor starting | Up to 4HP |
| Output waveform | Pure sine wave (same as input in bypass mode) |
| Output voltage | 120VAC |
| Output frequency | 50 or 60Hz (set by SW4) |
| Nominal efficiency | > 88% (peak); line mode > 95% |
| THD | < 10% |
| Transfer time | 10 ms (max) |
Battery (DC input)
| Nominal input voltage | 12.0VDC |
|---|---|
| Minimum start voltage | 10.0VDC |
| Low battery alarm | 10.5VDC / 11.0VDC |
| Low battery trip | 10.0VDC / 10.5VDC (set by SW1) |
| High voltage alarm | 16.0VDC |
| Low battery restart | 13.0VDC |
| Idle consumption | 45W; 18W in power-saver mode (spec sheet: 19W) |
Charger
| Charge rate | 120A ± 5A |
|---|---|
| Charge current | Adjustable 0-100%, or off |
| Charging | 3-step smart charger |
| Battery type settings | 9, including LiFePO4 |
| AC input range (grid or generator) | 90-135VAC / 100-135VAC (set by SW2) |
| Overcharge protection shutdown | 15.7V |
| Transfer switch / bypass breaker | 40A |
General
| Auto generator start | Yes |
|---|---|
| Outlet | GFCI |
| Remote control | LCD remote with cable, included |
| Battery temperature sensor | BTS cable included |
| Protection | AC input over/under voltage, low/high battery, over temperature, overload, short circuit, back-feed |
| Working temperature | 14°F to 104°F (-10°C to 40°C) |
| Mounting | Wall mount |
| Dimensions | 25.6 × 9.1 × 7.5 in |
| Weight | 62.2 lb |
| Shipping size / weight | 30.3 × 13.4 × 12.8 in, 71 lb |
| Warranty | 1-year (LFP series manual) |
| Model / SKU | LFP4K12V120VSG |
What's in the box
Package contents as listed by SunGoldPower.
Documents & certificates
Official files from SunGoldPower.
Customer reviews
Reviews from Sun Energy Depot customers, collected by Judge.me.
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