Description
More of your battery energy reaches your PC
In an RV or off-grid workspace, a conventional desktop often takes battery DC through an inverter to AC, then through an ATX power supply back to DC. Each conversion consumes energy. This DC-ATX supply converts a suitable DC source directly into the rails used by your motherboard, CPU, graphics card and drives. A good mains PSU can already be efficient; the opportunity here is to remove the extra conversion stage.
Conventional PC supply
Battery DC → inverter → AC PSU → PC
Direct DC-ATX supply
Battery DC → DC-ATX supply → PC
Desktop gaming, work and everyday browsing off-grid
Build a desktop for an RV, a battery-backed workspace or a cabin with a suitable DC electrical system. The board replaces the conventional AC PSU’s conversion function; it is an open-board component, not a drop-in enclosed ATX box. Check the mounting bracket, protection, airflow and cable routes for your case.
RTX 3070 + Ryzen 7 7800X3D: a transparent runtime example
Replacing a less efficient AC PSU and inverter
With the less-efficient setup modelled here, battery draw during gaming falls from about 451W to 339W: roughly 113W less, a 25% reduction. Estimated gaming runtime rises from 10.2 to 13.6 hours on the specified battery—about 3 hours 24 minutes extra. At idle the model saves about 39W (35%); while browsing, about 41W (30%). These are conditional calculations, not measured savings or an estimate of what most customers own.
Battery basis: 51.2V nominal LiFePO4 × 100Ah = 5.12kWh; 90% usable gives 4.608kWh. Results cover the PC tower only, excluding the monitor, router, other loads and cable losses. A 12V 100Ah battery stores much less energy and cannot connect directly to this product.
Less-efficient setup assumptions (idle / browsing / gaming): AC PSU 70 / 75 / 80%; inverter 85 / 88 / 90% effective, including operating overhead; DC-ATX 92 / 94 / 96%. These are illustrative values for an older or inefficient setup, not efficiencies inferred from a missing Bronze badge. Certification alone cannot tell you the efficiency at your actual load.
Modelled battery draw
| Workload | PC DC load | Inverter + AC PSU | DC-ATX |
|---|---|---|---|
| Desktop idle | 65W | 109W | 71W |
| Web browsing | 90W | 136W | 96W |
| Gaming | 325W | 451W | 339W |
Modelled runtime on the same battery
| Workload | Inverter + AC PSU | DC-ATX | Extra runtime |
|---|---|---|---|
| Desktop idle | 42.2 h | 65.2 h | 23 h 2 min |
| Web browsing | 33.8 h | 48.1 h | 14 h 20 min |
| Gaming | 10.2 h | 13.6 h | 3 h 24 min |
With only 90% DC-ATX efficiency during gaming, the less-efficient AC scenario still calculates about 90W less battery draw (20%) and roughly 2 hours 33 minutes extra. The actual result depends on both conversion chains.
Compare with a more efficient AC setup
In the gaming scenario below, calculated battery draw falls from about 393W to 339W: roughly 54W less, or 14%. On the specified 48V-class 100Ah battery, that means about 1 hour 52 minutes extra gaming. These are planning estimates, not measurements of this PSU or a tested complete PC.
Modelled battery draw
| Workload | PC DC load | Inverter + AC PSU | DC-ATX |
|---|---|---|---|
| Desktop idle | 65W | 85W | 71W |
| Web browsing | 90W | 114W | 96W |
| Gaming | 325W | 393W | 339W |
Modelled runtime on the same battery
| Workload | Inverter + AC PSU | DC-ATX | Extra runtime |
|---|---|---|---|
| Desktop idle | 54.2 h | 65.2 h | 11 h |
| Web browsing | 40.6 h | 48.1 h | 7 h 35 min |
| Gaming | 11.7 h | 13.6 h | 1 h 52 min |
Assumed efficiencies (idle / browsing / gaming): AC PSU 85 / 88 / 92%; inverter 90% effective at each load, including operating overhead; DC-ATX 92 / 94 / 96%. The supplier states >96% headline efficiency but publishes no load curve. These selected values are modelling assumptions, not guaranteed efficiencies.
Inputs, method and sources
The gaming budget is 325W at the PC rails: about 220W GPU + 67W CPU + 38W for motherboard, memory, storage and fans. Independent measurements provide the GPU/CPU anchors; 65W idle and 90W browsing are illustrative whole-PC budgets. These are not measured results for this exact component combination. Games, frame-rate limits, monitors and background activity change demand.
Battery power = PC DC load ÷ conversion efficiency; multiply the inverter and AC-PSU efficiencies for the conventional path. Runtime = 4,608Wh ÷ battery power. Figures are rounded. For the more efficient AC setup, at 90% DC-ATX efficiency instead of 96%, the same gaming scenario saves about 31W and adds about 1 hour. If the inverter remains on for a monitor or other appliances, its remaining losses must be included; the full saving may not be realised.
Why show this scenario? A 2010 bit-tech laboratory test found only about 70% efficiency in a generic PSU, which also failed voltage-regulation checks. That historical result illustrates how poor efficiency can get; it does not describe today’s average PSU or a suitable gaming-PC build. Our 70/75/80% profile is a separate sensitivity scenario, not that unit’s measured curve.
Reference measurements and conversion background:
Choose the DC source and PC together
- 16–60V throughout operation: suitable 24V and 48V battery systems must stay in range during charging and discharge. Do not connect directly to a 12V battery or an uncontrolled solar panel.
- 500W is a conditional maximum: output is optimised for 48V and decreases above or below it. Forced airflow is required at maximum load. The +12V rail is rated at up to 40A, within the 500W combined limit. Allow for GPU transients and all other rails.
- Gaming compatibility requires a power budget: NVIDIA’s general RTX 3070 system guidance specifies a 650W PSU. Our 325W workload example does not override that recommendation or prove compatibility. Check your exact card, CPU, connectors, peak demand and the supplier’s limits before building.
- Thermal and mechanical requirements: 125 × 63 × 31mm board with heatsink/backplate; verify bracket and enclosure. Ambient range −10 to +70°C, with maximum output derating above 40°C. Fanless use requires reduced +12V load to keep the PSU below 65°C.
- Connections: one ATX 24-pin, one EPS 4+4-pin, two PCIe 6+2-pin, three SATA and one peripheral connector. Some GPUs need their own adapter. No ATX 3.x or 12VHPWR support is claimed. Use correctly rated battery protection, input wiring and fusing.
Download the PVShop technical datasheet (English PDF)
DC-ATX questions
Can I run this from a 12V leisure battery?
Not directly: the minimum input is 16V. A separately designed step-up stage would add losses and its own power limits. Choose a suitable 24V or 48V system for a direct connection.
Will it power every 500W gaming PC?
No. Input voltage, cooling, individual rails, connectors and transient loads all matter. The example is an energy calculation, not a compatibility certification.
Do I still need an inverter?
The PC tower does not need an inverter when supplied from a compatible DC source through this unit. Your monitor and other AC appliances may still need one.