Why Power Logging Should Happen Before Adding EV Chargers, Solar or Batteries

Why should power logging happen before adding EV chargers, solar or batteries? Because it shows how much power your property actually uses, on each phase and at what times, so new equipment is sized to your real load and your supply's limits. Without it, installers are guessing, which leads to chargers that trip the main switch, needless supply upgrades, solar inverters that shut down on high voltage, or batteries sized for a load profile you don't have.

⚡ Quick Answers: Power Logging

• What is it? A logger at the main switchboard recording current, voltage, power factor and demand over time.
• How long does it run? Typically one to two weeks of normal use.
• Is it disruptive? No. It's installed and removed with minimal or no outage, depending on the board.
• Is smart meter data enough? It helps, but usually lacks per-phase current, voltage and short peaks.
• What does it prevent? Nuisance tripping, oversized or undersized systems and unnecessary upgrades.
• Who needs it most? Older homes, strata buildings and businesses adding big new loads.

1. What a power logger actually measures

A power logger is temporarily connected at your main switchboard by a licensed electrician. Over the logging period it records current on each phase, voltage, power factor and demand at short intervals. The result is a clear picture of your baseline load, your true peak, when it happens, how evenly your phases are loaded and whether your local voltage runs high or low. That's information a switchboard inspection or a quick calculation can't give you.

2. EV chargers: will your supply cope?

A 7 kW single-phase EV charger draws around 32 amps for hours at a time. On an older Inner West terrace with a modest single-phase supply, electric hot water, air conditioning and cooking, that can push peak demand over what the supply or main switch can carry, especially on a winter evening. Logging shows how much headroom you really have. Often the answer is a charger with load management that throttles charging when the house is busy, rather than a supply upgrade. For strata buildings, logging is essential before planning shared charging. Our guide to what an EV charger installer should check covers the rest of the assessment.

3. Solar: voltage and export

In parts of Sydney, local network voltage can already sit at the high end of the allowed range. Add a solar system exporting on a sunny afternoon and the inverter can trip off on over-voltage, costing you generation you paid for. Logging voltage before installation lets the designer size the system and cabling to reduce voltage rise, and flag a network voltage issue early. It also shows your daytime usage, which determines how much solar you'll use yourself rather than export. Our guide to solar and batteries on Inner West terrace roofs covers the roof side of the design.

4. Batteries: sizing to your evening load

A battery earns its keep by covering your evening and overnight usage. Sizing one well means knowing how much you use between sunset and morning, and how high your evening peaks go. Logging gives you that profile, so you don't overpay for capacity you'll never cycle, or buy a battery that runs flat by 8pm. It also shows whether your backup circuits can realistically be supported during an outage.

5. Businesses and strata: evidence before spending

For Inner West businesses and strata buildings, logging is the evidence behind any big electrical decision: adding EV chargers to a car park, installing commercial solar, replacing a main switchboard, or applying to Ausgrid for more capacity. It feeds straight into the AS/NZS 3000 maximum demand calculation and often shows that better phase balancing or load management avoids an upgrade altogether. Our guide to commercial three-phase supply upgrades explains how that works.

6. What happens after logging

1. We review the data with you: peak demand, phase balance, voltage and usage patterns.
2. We calculate the added demand of the EV charger, solar or battery you're planning.
3. We recommend the simplest option: install as planned, add load management, rebalance phases, upgrade the switchboard, or upgrade the supply.
4. You get a written recommendation to share with your installer, strata committee or landlord.

How High Demand Electrical helps

We're a Level 2 ASP team (Licence 397193C) working across the Inner West. We install and remove loggers, interpret the data in plain English, and if an upgrade is needed, we handle the switchboard, consumer mains and Ausgrid side ourselves. That means your EV charger, solar or battery goes onto an installation that's ready for it.

Power Logging FAQs (Inner West)

What is power logging?

Power logging is temporarily installing a meter-grade logger at your main switchboard to record current on each phase, voltage, power factor and demand over time, so you can see your real peak load and when it happens.

How long should power logging run?

Usually one to two weeks of normal use, so it captures weekday and weekend patterns. For businesses, it should cover typical trading, including the busiest periods.

Can I use my smart meter data instead?

Smart meter interval data is a useful starting point for usage patterns, but it usually doesn't show per-phase current, voltage or short peaks, which matter for sizing EV chargers and checking supply capacity.

Will power logging tell me if I need a supply upgrade?

Yes. Combined with a maximum demand calculation for the new equipment, it shows whether your existing supply can carry the added load, or whether load management or an upgrade is needed.

Why does voltage matter for solar?

If your local network voltage already runs high, a solar inverter can trip off on over-voltage during sunny periods. Logging voltage beforehand helps the installer design around it and flag it early.

Book Power Logging Before You Buy

Planning an EV charger, solar or battery? Book power logging first, or call 0402 559 777. It's the cheapest way to make sure the expensive part goes right.