About GridSpec
Independent engineering answers for backup power buyers
GridSpec: Global EV, Solar & Battery Compatibility Lab exists to answer one deceptively simple question: “Will this battery actually run that appliance?” Manufacturer pages highlight battery capacity, yet most failed purchases come down to inverter surge limits, missing 240 V split-phase output, or wiring that was never sized for a continuous load. We built GridSpec so homeowners, RV owners, off-grid builders and electricians can check a pairing in seconds and see the engineering behind the answer.
Today the lab covers 35 portable power stations, whole-home batteries and hybrid inverters and 53 high-draw appliances and electric vehicles — 1,855 individually calculated compatibility reports, each reviewed against North American and international wiring standards.
Our methodology
Every verdict is produced by the same open, deterministic calculation engine. There is no manual scoring and no paid placement. Each pairing must pass three checks:
- Continuous output — the inverter’s continuous rating must equal or exceed the load’s running watts. Above 80% utilisation we flag the pairing as high-load.
- Surge output — the inverter’s surge rating must cover the load’s starting (locked-rotor) watts, the moment when motors and compressors draw several times their running power.
- Voltage — in North America, a 240 V load requires a 120/240 V split-phase source. In 230 V markets, all sources and loads in our dataset are single-phase 230 V.
Runtime, recharge and wiring calculations then use the following assumptions:
- 85% system efficiency from DC battery to AC outlet, reflecting LiFePO4 battery management overhead and pure-sine inverter losses.
- 80% solar harvest factor for MPPT conversion, cell temperature and soiling, with 4.5 peak-sun-hours per day as a conservative planning average.
- NEC (NFPA 70) 125% continuous-load sizing for breakers and conductors, standard breaker sizes from Section 240.6, copper ampacities from Table 310.16 (75 °C column) and resistances from Chapter 9 Table 8.
- IEC 60364 / BS 7671 protective-device coordination (Ib ≤ In ≤ Iz), IEC 60898 MCB ratings and PVC copper cable ratings for reference method C.
- 3% maximum voltage drop on the branch circuit between the power source and the load, calculated for the round-trip conductor length.
- EV supply equipment is modelled as a constant-current load; in 230 V markets the pilot current is capped at the 32 A single-phase Type 2 limit.
Where our data comes from
Power-source specifications — battery capacity, continuous and surge output, solar input limits, output voltages and receptacles — are taken from manufacturer datasheets and user manuals. Appliance running and starting watts come from nameplate ratings, manufacturer installation guides and published locked-rotor amperage figures, rounded to representative values for each product class. EV charging loads are derived from the current rating of each vehicle’s portable or mobile connector. When manufacturers revise a specification, we update the dataset and every dependent report is regenerated automatically.
Editorial independence & how we are funded
GridSpec is free to use. We are funded by display advertising served by Google AdSense and by affiliate commissions when readers buy hardware through some of our outbound links (for example, Amazon Associates or manufacturer affiliate programmes). Affiliate relationships never change a calculation: the engine has no input for commission rates, and the “suggested alternative” logic always recommends the leanest unit that passes every check. Advertisers have no influence over our content.
Corrections
Accuracy is the product. If you spot an outdated specification, a calculation you disagree with, or a code reference that has changed, please tell us through our contact page. We review every correction request and, where warranted, update the dataset and note the date of the change.
Safety first
GridSpec provides engineering estimates for planning and purchasing decisions. It is not a substitute for a site survey by a licensed electrician, and nothing on this site authorises you to work on live circuits. Connecting any generator, battery or inverter to a building’s wiring requires a listed transfer switch or interlock and, in most jurisdictions, a permit. Please read our Terms & Electrical Safety Disclaimer before relying on any result.