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It takes how long?! Understanding EV and PHEV Charging.

Updated: Jun 4, 2021

Most of us don’t fully remember high school physics, just some of the basics. But it’s the basics that help us understand how long it takes to charge NEVs (New Energy Vehicles, the catch all phrase for Electric, and Plug-In Hybrid vehicles).

Online there is so much information and misinformation about what to use, especially in New Zealand where our charging habits have been formed in part by charging New Zealand’s most popular BEV, the Nissan Leaf. The problem with these habits is that they have been formed with a focus on charging a cheap car with a 24 kWh battery, cheaply, rather than thinking about larger batteries, that will come with newer vehicles.

Simply put, the bigger batteries in BEVs take longer to charge, and are likely to need some investment in home charging infrastructure, whereas most PHEVs and 24 kWh Leaf do not (at a push). Some of the more inventive kiwi solutions (caravan plug anyone?) are short sighted, and ultimately will cost more in the long run.

Having said that BEV batteries are seldom fully charged from empty at home, rather they are repeatedly topped up. But fully charging a 60 kWh battery at home from an 8A 230V mode 2 charger (with a large array of secondary names such as trickle charger, granny charger, EVSE, AC charge cord) is utterly painful. Boost Auto knows – we have tried.

So, here’s a quick infographic about what chargers you need in your home or business for your pool fleet or your company cars. Understanding usage is key. Pool cars sit around, often not utilised at night – therefore they do not need fast chargers. However just like company vehicles they need to be fully charged and ready to go in the morning. Plug-In Hybrids have smaller batteries – therefore charging times are shorter. A 22 kWh charger for a hybrid is overkill in most situations.

In fact, most charging (over 70%) is done at home at night (or at the office in the case of pool cars), where there is less time pressure for a fast charge. This means your solutions don’t need to be fast charge first, they should be overnight charge first. This in turn drives down the charging infrastructure cost. And that can make a massive difference for a large fleet.

Lastly these calculations ignore that many vehicles aren’t fully charged at a constant rate. Battery Management Systems assist in managing battery longevity, and so typically a vehicle charge rate will fall (and may even be blocked in certain circumstances) once a vehicle reaches 80% charge. However, this fact over complicates the bigger picture, unless you are constantly running your vehicle near its full range on a very regular basis.

Boost Auto have created this simple infographic to help the EV buying public and businesses understand the detail of charging, and given recommendations (shown in a rather fetching salmon pink) for what charging infrastructure you might need. This is a minimum, rather than a one size fits all solution for all businesses. Your usage type, fleet size, and facilities will all effect the optimum charger solution for your business.

As a reminder to those that are interested...Volts (V) x Amps (A) = Watts (W).

Happy charging!

Boost Auto is an automotive consultancy working in five main areas.

  1. Sales and Marketing effectiveness for brands and dealers

  2. Green fleet facilitation for large corporates

  3. Go To Market strategies for emerging brands

  4. Market Insights

  5. Business Planning and facilitation

You can contact us at

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