Technology

The Challenge was a massive test of the latest in electric propulsion technology, pushing the boat and battery management system to the limits. For the boat geeks out there, here is some information on the boat and the systems we used.

Electra

Electra is a modified 6.5m aluminium Galaxy RIB built by Ukrainian company, GALA.

She was modified for electric propulsion as a 'one off' by Dutch company, The Greenwave, who raised the deck to install the two 63kWh batteries. The powertrain was supplied by Norwegian company EVOY with the system managed by a Battery Management System which can be remotely monitored. The boat was coded to CE category C.

The boat had the following equipment onboard:

- SART

- EPIRB

- 4 person liferaft with light

- VHF with DSC

- AIS

- Garmin chart plotter with GPS

- Kill cord

- Evoy system management screen with backup navigation charts

- Shark suspension seats

- Anchor and sea anchor

- Flares

- Medical Kit

- Grab bag (handheld VHF, rations, torch, etc.)

- Fire suppression system and handheld extinguisher

- Satellite radio

Charging

The boat can charge using AC or DC power. It is faster and more efficient to charge with DC and recently the marine industry has seen a growth in availability, especially along the South Coast. Our DC charging capacity is limited to 0.7C, which means for a 63kWh battery the max DC charge it can accept is around 44kW. Even with a 75kW fast charger the charge rate will remain at 44kW.

Our AC charging capacity was controlled by the On Board Charger (OBC) which is 6.6kW. For a 32A 240V single phase supply offering just over 7kW we would be limited to charging at 6.6kW.

For the Challenge we needed to be able to fast charge at as many locations as possible, including unplanned stops!

Where a fast DC charger was available along the South Coast or elsewhere we hooked up to that and were charged in a jiffy!

Where a 63A or 32A 415V 3 phase red commando or CEE socket was available we charged using the Kempower AC-DC inverter giving us a 40kW or 20kW DC charging speed respectively. These connections made up around 35 or our planned charges.

Where an EV Type 2 charger was available close enough to a wharf wall we were able to charge at 6.6kW AC using a standard Type 2 cable.

Where a 32A 240V single phase blue commando or CEE socket was available we were able to charge at 6.6kW AC as above.

Where we had to stop unexpectedly and top up the charge then we generally recovered the vessel and took it to a fast car charger... but we needed to park across all the charging bays to ensure the DC cable could reach so this was always done in the middle of the night!