Charging

photo

Standard charging method by IEC lead, using on-board charger. Charging the Zero using this method alone requires around 9 hours.

The electric motorbike I own, the Zero DSR ZF13.0 (2016 model) is capable of around 80-100 miles on a single charge, but this all depends on how and under what conditions it is ridden. The bike is charged using an IEC lead, more commonly called a kettle or PC lead, which plugs into the side of the bike and charges it using the bike’s onboard 1.3 kW charger.

The bike is fitted with a nominal 13 kWh battery, but in fact 11.4 kWh of the battery is usable. The battery chemistry used is Lithium Nickel Manganese Cobalt (NMC). NMC differs from the Lithium-Cobalt used in phones and laptops. The latter ages quickly and doesn’t cycle (recharge and discharge) as well, making it unsuitable for the purposes of powering an electric motorbike. NMC should be good for 10 years, but is in any case warrantied for 5 years, which is longer than the warranty on the bike.

At 1.3 kW, using the bike’s on-board charger, a full charge from empty would ordinarily take around 9 hours. That’s fine for day-to-day trips, my check rides when observing, and the odd club social ride, but it poses a problem when undertaking an 850ish mile journey from Land’s End to John o’Groats. Unless I was prepared to wait 9 hours between charges, which could spin the trip out to take several days, I had to find a way of charging more quickly.

Unlike most electric cars, the Zero doesn’t have a rapid charge capability, where the battery can be charged to almost full in around half an hour. The quickest way to charge the bike would have been to install the optional Charge Tank, offering a 3 hour charge time using an additional onboard charger, installed where the fuel tank sits in normal petrol bikes, but this comes in at the princely sum of around £2500, which in my case would represent a large sum of money for not a great deal of benefit.

photo

Two borrowed external Quiq chargers (courtesy of Streetbike), adding an additional 1kW charge capacity per charger, pictured with 6 way, 32 amp power strip.

The other realistic alternative (aside from third-party solutions, which might threaten the validity of the bike’s warranty) was to use Zero’s external ‘Quiq’ charge units. These resemble large power packs with standard domestic plugs and can be plugged into the bike’s auxiliary charge port, each one boosting the charge rate by a further kilowatt. One, two, or four can be used on an individual bike, each adding an additional kilowatt of charging, but again, these don’t come cheap as an optional extra at around £700 each.

Streetbike also agreed to contact Zero’s European head office in the Netherlands with a view to obtaining four external quick chargers for the duration of the trip, which would allow us to keep charge times during the day to around three hours. They genuinely couldn’t have been more accommodating and helpful in this respect.

On the basis of two of us undertaking the journey, we’d require six standard power sockets for each charging stop, which would support a combined electrical draw of 6.6 kW. For those in the know, that’s not the kind of power you can draw safely from one power socket down a standard extension lead. We could reasonably manage with four sockets at any stop, by running each pair of external chargers through a two-way extension, since that would only draw 2 kW per pair, and then the on-board charger would draw 1.3 kW from another socket. Four sockets didn’t appear to be too difficult a prospect to find at a stop, but there was also another possibility.

There are three levels of charging standard electric cars. The slowest, called ‘slow’ charging involves charging a car using a standard domestic socket and, using a 24 kWh Nissan LEAF as an example, will take around ten hours from flat to 100% charged. This is also the normal method used by the Zero.

photo

Charging the Zero DSR electric motorcycle at Eco Cars' Orkney HQ, courtesy of Jonathan Porterfield.

The next fastest, called ‘fast’ charging, is what most owners will end up using at home. This involves installation of a dedicated charge point at home which provides for charging of the car at 16 amps or 32 amps, offering 3.6 KW or 6.6 kW respectively, depending on the car. A LEAF with an on-board 3.6 kW charger will fully charge from empty in around 6.5 hours; one with the 6.6 on-board charger in around 3.5 hours. Fast chargers are also commonly installed in public car parks and supermarket car parks, which are also commonly blocked, or ‘ICEd’ by internal combustion engine vehicles. This method can also be used by the Zero using the optional charge tank referred to above.

The fastest method of charging an electric car is called ‘rapid’ charging, and typically offers 50 kW of power, allowing the car to charge to 80% in around half an hour and 100% in around an hour (the last 20% is slower to protect the battery, and therefore most people charge to around 80% when on the move). This method is not available to the Zero, which is a great pity, because if it were, it would in theory offer a charge in around 15-20 minutes.

Although the bike constrained us to charging using domestic sockets, it did occur to me that there might be a possibility to charge from a fast charger if there were a lead available which allowed us to go from UK domestic sockets to a fast charging (Type 2/Mennekes) plug. This wouldn’t improve charging times, which are constrained by the chargers, but would open up the possibility of charging at public car charging points and anywhere which had a domestic fast car charger facility and would make charging relatively easy, only requiring one fast charge socket rather than four domestic sockets. Such a lead doesn’t in fact exist – understandable, since it’s not really of much use to anyone ordinarily, but I was able to source a 32 amp Type 2/Mennekes to ICC (or Commando) socket cable. 32 amps would be required to cope with 6.6 kW of charging. To connect to that, I managed to find a rack mount 32 amp 6 way power strip which terminated in a Commando plug. Combine the two and in theory, we could charge both bikes from a single fast charge point.

When the cables arrived, I tried connecting the bike to my home fast charge point and was delighted to see it worked. A trip to the local Asda (where all four spaces were ICEd) allowed me to test the cable on a public fast charge point, and it worked fine there too. Having confirmed that to be the case, I was happy to proceed on the basis of stopping at either fast charge points or places with four domestic sockets.


Fast Charging: Part 1

Fast Charging: Part 2