One of the most exciting and innovative EV chargers currently available is the Zappi v2. Made in Britain by Lincolnshire based company, Myenergi.
The feature that makes it really attractive is the integration with grid-tied microgeneration systems, specifically solar PV arrays or wind turbines which are both commonplace nowadays.
Any potential buyers that don’t have PV/wind turbines should not be put off though. The Zappi works as a regular fast charger like any other and has many great features that we will look at.
The v2 is the second Zappi model from Myenergi replacing the v1. offering extra safety features making installation easier to comply with the BS7671 Electrical Wiring Regulations.
Grid-tied microgeneration compatibility
The Myenergi Zappi’s main feature is the compatibility with microgeneration, and for this review, we will assume a PV array is connected (although wind turbines work in the same way).
The Zappi has two eco modes to select between, eco and eco+, and these determine how the car is to be charged in relation to the energy being produced.
When set to eco mode, Zappi will monitor the energy consumption in the home, and energy created from the PV array. It then adjusts the charge rate to the EV so that the minimum amount of grid-supplied power is used. If at any time the PV array generates less than 1.4kW of power then the Zappi will continue charging from the grid only.
Myenergi Zappi LCD display showing grid import, PV generation and energy consumption in the home.
When set to eco+ mode the Zappi works in a similar way but this time if the Zappi does not receive enough surplus energy from the PV array then charging will be paused, it will then continue when either the energy consumption from the rest of the house has dropped or the PV array generates enough surplus energy.
The ‘green’ setting can be adjusted, so for example, if set to 100% then the EV will only charge when there is enough surplus energy from the PV array (1.4kW) but as soon as it drops below this amount then charging will stop, and only recommence when it reaches the threshold again.
This is the cheapest and ‘greenest’ way to charge but may not always be the most practical. Changes in the weather may cause energy generation to decrease, or during the day various appliances in the home are running, therefore using the surplus power. It is then recommended to set the ‘green’ level to maybe 80% this ensures that the EV will always be receiving a small charge even when the PV array may not be generating.
This setting should be altered seasonally, with the ‘green’ setting lowered to 20-50% during winter months (depending on where you live) where there are fewer hours of sunlight, and raised to 80-100% during the summer. This feature is a fabulous selling point for the Myenergi Zappi which other manufacturers are bound to follow.
Another premium feature not available with many other EV chargers is load balancing. This safety feature prevents the main fuse from overloading and potential rupture.
EV chargers place a huge demand on the grid as they are running for long periods of time. Although household appliances such as electric hobs and showers draw a similar current they are not on for such long periods compared to EV chargers. This is a concern for not only the National Grid but charge point installers who have to ensure the added EV charger will not cause an overload.
Most EV chargers will be set to charge at 7kW (32A) or 3.5kw (16A) and will have to be purchased in relation to the existing current demand in your home. Homes with various electrical showers, hobs and electric heating would be recommended to purchase a slower 3.5kW charger or risk possibly blowing the main fuse.
The Zappi however has a load balancing device that monitors the power usage of your home and will reduce the charge to the EV if too much demand is drawn in the rest of the home.
For example, if the main fuse of the property was 60A, and the rest of the home was already drawing 40A, when the Zappi is plugged into an EV the charge rate will reduce from 32A down to 20A. This keeps the load within the 60A set limit. Therefore doing away with the concerns of overloading that comes with other EV charge points.
To monitor loads the Zappi uses a CT clamp. This clamp is placed around the cables from your electric meter to monitor energy usage. These clamps can be hard-wired to the Zappi, or use a wireless energy monitor that sends a signal to the Zappi. This monitor is known as the Harvi.
Harvi energy monitor
The Harvi does not use batteries or need plugging in, it harvests energy from the electromagnetic field produced by the meter cables. This is great for instances when the electric meter is in a remote location from the consumer unit.
The Harvi can also be used to monitor microgeneration and battery storage that is not in close proximity to the Zappi.
Myenergi Harvi installed in electric meter cabinet, with CT clamp connected (bottom right)
PEN fault detection
Most EV charge points will require an earth rod to be installed as an increased safety measure, this is in the event of a loss of the grid’s supply neutral. This occurrence is quite rare but is a dangerous one. However, the Zappi monitors the neutral conductor and in the event of a fault the charge to the EV will be interrupted.
This device omits the need for an unsightly earth rod being installed in the ground next to the EV charge point. Although this feature is probably not top of the list for potential buyers nevertheless it is another very important one and a great reason to purchase a Zappi.
Smart Hub and app
The Zappi is a smart EV charger and can be connected to a network via the Myenergi hub. This smart hub is a gateway to connect to the Zappi via your phone or tablet with the Myenergi app. From the app, charge settings can be changed and energy consumption monitored.
The Myenergi Hub is connected to your router via an Ethernet cable
The app features a simple interface showing how much energy is being drawn from the grid or PV array, and also how much energy is used in the home and to charge your car.
In the center is the ‘green’ icon, this shows the percentage of green energy being used.
In this photo we can see that 6.3kWh of electricity is being generated by the PV array. With 0.9kWh being used by the home, the surplus 5.4kWh is charging the electric vehicle. This is 100% ‘green’ electricity as nothing is being pulled from the grid.
Even when an EV is not charging the app can show energy consumption in the home. The above photo shows surplus generated electricity being diverted to battery storage.
Boost times can also be programmed via the app for overnight charging. This is essential for anyone who has a cheap overnight electricity tariff like the Octopus Go tariff from Octopus Energy. This tariff offers charging rates of 5p per kWh for 4 hours overnight, which is great for getting a cheap top up and can be timed via the smart boost facility.
The app also allows connectivity to the Myenergi Eddi solar diverter. This unit allows excess energy generated from PV systems to heat your hot water. See our review here.
UPDATE: As of 25th March 2022 the Myenergi Zappi will have built-in WiFi and a LAN port making connection to your network easier and omiting the need for a Hub. We will review the new Zappi once we have installed one.
Zappi model options
The Myenergi Zappi is available in both single and three-phase versions. The single-phase unit has a charge rate of 7kWh and three-phase 22kWh.
Most domestic properties in the UK only have a single-phase supply, with commercial properties only really having the benefit of a three-phase supply.
As well as the power options there are also variations in socket or tethered lead models.
The socket model has a Type-2 socket on the front with customers having to use their own charge lead.
Tethered versions have a fixed 6.5m lead. The lead can be wrapped around the unit when not in use to keep it tidy and prevent damage.
All these variations come in either a black or white finish to suit your property.
Zappi Model Numbers
Zappi-207UB – 7kW, Untethered, Black
Zappi-207UW – 7kW, Untethered, White
Zappi-207TB – 7kW, Tetehered, Black
Zappi-207TW – 7kW, Tethered, White
Zappi-222UB – 22kW, Untethered, Black
Zappi-222UW – 22kW, Untethered, White
Zappi-222TB – 22kW, Tethered, Black
Zappi-222TW – 22kW, Tethered, White
Myenergi Zappi 7kW Tethered model in black
Overall the Zappi is a fantastic charger. It will not only please those who have PV arrays, or those who like their gadgets but anyone who uses it.
The Zappi is slightly more expensive than some of the other EV chargers available, but you are paying for some great features, and also have peace of mind you are using without a doubt the safest charger available.
Although the Zappi unit is more expensive than others the installation costs should cost less – due to the omission of the earth rod. This equals out the overall cost.
The styling of the Zappi is also a lot sleeker than other charge points. With the omission of the earth rod, only one cable needs to be installed to the unit making it a little more aesthetically pleasing.
Myenergi are a forward-thinking company always trying to improve their products and regularly add new features. They also promote sustainability and this reflects in their products. For example, the Zappi comes in completely plastic-free recyclable packaging, small touches like this add to the Zappi experience.
All in all a fantastic EV charge point!