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You are three floors up in a CBD fit-out, the core drilling is booked for Thursday, and the building manager has just told you no petrol generator is coming inside. That is the exact job a battery-powered generator for construction NZ crews now solves. This article covers what one charge of the Instagrid One portable battery power unit actually gets you on a construction site, where it pays for itself, and the jobs it will not cover.
The power problem on construction sites
The problem is rarely that you cannot get power. It is that the power source you can get is not allowed where the work is.
Noise is the first wall you hit. Construction noise in New Zealand is assessed against NZS 6803:1999, which most district plans reference under the Resource Management Act, and it works in time bands. For residential neighbours on a long-running job, the recommended upper limit is 70 dB LAeq between 7.30 am and 6 pm on weekdays, dropping to 45 dB LAeq between 8 pm and 6.30 am. Sunday daytime sits at 55 dB. A petrol generator idling at the boundary spends a large slice of that budget before a single tool is switched on. Your resource consent may tighten those numbers further, so check it.
Fumes are the second wall. WorkSafe NZ is direct about this. Liquid fuel engines should never be run in confined spaces or poorly ventilated areas, and the first control WorkSafe recommends is to use electric or pneumatic tools instead of fuel-powered ones wherever reasonably practicable. Carbon monoxide has no colour, no smell and no taste, and it has killed people at work in New Zealand. Basements, lift shafts, tunnels and partly sealed interior fit-outs are places a petrol unit either cannot go at all, or can only go with forced extraction and atmospheric monitoring that somebody has to pay for.
Getting power to the work is the quiet cost. On a multi-level build, you either run leads back to a temporary board, or two people carry a generator and jerry cans up a stairwell. Both burn labour hours that nobody put in the quote.
Fuel security is the last one. A generator left on site over a long weekend is a target, and so is the fuel sitting beside it. Stored petrol also brings its own hazardous substances obligations, container rules, and spill risks to a site that already has plenty to manage.
The broader petrol-versus-battery argument, including what each costs to run over a year, is covered in the full petrol generator comparison. This article stays on the site.
What a construction generator delivers
The unit outputs 230V at 16A, with 3,500W of continuous power and a peak of 18,000W. That peak headroom is what lets a core drill or a table saw draw its startup surge without the supply sagging. Energy capacity is 2.1 kWh per unit, and up to 6.3 kWh when three units are linked together.
It weighs 20kg, measures 420 x 210 x 420mm, and recharges to full in two hours from an ordinary 230V outlet. It is made in Germany and carries a four-year warranty. According to Instagrid, the system has been used on more than 50,000 sites across Europe. One person carries it in one hand, which is the whole point of a stairwell.
What one charge actually gets you
These are Instagrid operator figures for the tools a construction and civil crew already owns. They count actual tool run time, not the hours the unit sits switched on between cuts.
| Tool | Power draw | What one charge gets you |
| Diamond core drill | 3,300W | Around 32 holes, 150mm diameter by 150mm deep |
| Construction table saw | 3,000W | Around 4,100 cuts in 50 x 100mm timber |
| Concrete mixer, 180 litre barrel | 600W | Around 11.5 tonnes of concrete mixed |
| Recharge from the flat | Standard 230V outlet | Back to 100 per cent in two hours |
Read the mixer figure alongside the recharge time, and the shape of a working day becomes clear. Mix through the morning, put it on charge over lunch, and carry on.
Where a battery-powered generator earns its keep on construction sites
Residential and CBD fit-outs with noise limits
This is the clearest win. A silent supply takes the generator out of your noise calculation entirely, which either buys you an earlier start, a later finish, or the ability to work above an occupied floor without the building manager standing behind you. On tight suburban sections in Auckland and Wellington, where the neighbour's window is four metres from your saw bench, it also eliminates the complaint that would stop the job.
Core drilling and concrete cutting on a live site
Core drilling is high draw work in short bursts, which is exactly what battery power suits. Around 32 holes at 150mm diameter is a solid day of penetrations for services. Because the unit is sealed and passively cooled, you can set it down beside the rig rather than running a lead back to the board, and there is no cable route across a live walkway to barrier off.
Remote civil work with no mains and no fuel run
For a rural culvert, a bridge abutment, or a trenching job with no nearby supply, the trade-off is typically a generator plus a fuel plan. A charged unit in the ute removes both. You charge it overnight at the yard, and at the end of the day, it goes home with you rather than staying out where it can be stolen. For crews working across several rural sites in a week, that also means no midweek fuel run and no jerry cans rolling around the tray.
Where it will not work
Being straight about this saves everyone a wasted site visit.
Sustained draw above 3,500W is the hard limit. If your machine needs more than that continuously, a single unit is the wrong tool, no matter how good the peak figure looks.
All day high load is the second limit. A 3,300W core drill pulling constantly will empty 2.1 kWh in well under an hour of actual cutting. The published figures work because real drilling is intermittent. If your crew genuinely runs high-load tools back-to-back all day, plan for linked units, a charging point, or mains.
Three-phase equipment will not run from a single 230V unit. Neither will anything need a 32A supply.
And multi-day work with nowhere to plug in is not the application. The unit needs roughly two hours on a standard outlet to come back, so it wants a yard, a van or a site board somewhere in the cycle.
When you need three-phase
If your gear is 400V, you need the linking hardware rather than a bigger single unit. Instagrid Link Max combines three Instagrid One units into a portable 400V three-phase supply rated at 11 kW with 54 kW peak, covering three-phase core drills, larger saws, and industrial welders. It is worth knowing the two products apart. Instagrid Link triples energy capacity to 6.3 kWh but remains single-phase, while Link Max offers 400V three-phase. Talk to Proline about availability before you plan a job around it.
What to check before you buy a size generator
Work through these before you enquire, and the conversation gets a lot shorter.
What does your highest draw tool pull continuously?
Not its peak, it's steady state. If that figure is over 3,500W, a single unit is out.
How much of your day is actual tool run time?
Most crews overestimate this. Two hours of real cutting across an eight-hour day is common, and that is what the runtime figures measure.
Where will it charge?
A yard, a van inverter, a site board or a nearby socket. If the answer is nowhere, you need a second unit rather than a bigger one. If the site also needs backup when mains power drops, ask for advice on generator options for construction with automatic transfer switching to reduce downtime.
Do you have a three-phase or 32A gear in the mix?
If yes, size the solution around the linking hardware from the start.
Who is carrying it, and up how many flights?
At 20kg it is a one person lift, but that still matters if it is going up six levels twice a day.
What are your consent conditions?
If your resource consent sets tighter noise limits or shorter hours than the standard, that changes the value of a silent supply, usually upwards.
Comparing options across the wider category is worth doing too. The portable power stations range sits alongside the rest of the power equipment lineup, and the Instagrid range covers the linking hardware and base units, while broader options are available to meet different site capacities, for example, from 8kVA to 780kVA.
Talk to us about your site
If you know your load figures and the total power needed for the project, along with your consent conditions, we can tell you fairly quickly whether one unit will cover the job or you need two, and help select the right setup. Contact the team for information on battery applications, current stock, price, and which option to choose when mains power is limited or unavailable. Enquire via the Instagrid One product page or call the team on 0800 699 353 for expert advice from a proven source for construction professionals.
