We recently had the honour of being approached by the Cambridge University Eco Racing team (www.cuer.co.uk) to build a battery pack for a solar-powered vehicle.
CUER is a student organisation which builds solar powered vehicles to race in the World Solar Challenge (https://www.worldsolarchallenge.org/event-information). The next race will take place in Australia later this year and this was an exciting project which we just had to get involved in
The brief was to build a new battery pack, consisting of 408 lithium-ion cells (Panasonic NCR18650GA, 34 series by 12 parallel).
Our response was to build a battery pack using copper interconnects welded by the unique Sunstone Engineering 250i2 EV (http://sunstonewelders.com/applications/batteries/ev-battery-welding/). Copper is the ultimate conductor for battery interconnects and is more than 4 times less resistive than nickel. Potentially all things being equal, a copper interconnected battery would potentially be a winning battery. In any ev, the battery is the heart of the system. With the least resistance of the battery pack, highest power levels will be achieved with less voltage sag and less heat generated by the pack.
We were provided with 2000 cells and set about individually testing the IR and storage voltage of each cell and chose those with the same voltage and lowest IR. It was a time consuming exercise to say the least. We also chose the cells with the highest storage voltage. Every little bit helps when it comes to batteries. In short, with such a build, we went to the nth degree to ensure the pack was as well put together as possible.
It was a privilege to be asked to build this battery pack and as such, we offered our expertise and materials pro gratis. We wish the team every success and will be keenly following their progress!
CUER is a student organisation which builds solar powered vehicles to race in the World Solar Challenge (https://www.worldsolarchallenge.org/event-information). The next race will take place in Australia later this year and this was an exciting project which we just had to get involved in
The brief was to build a new battery pack, consisting of 408 lithium-ion cells (Panasonic NCR18650GA, 34 series by 12 parallel).
Our response was to build a battery pack using copper interconnects welded by the unique Sunstone Engineering 250i2 EV (http://sunstonewelders.com/applications/batteries/ev-battery-welding/). Copper is the ultimate conductor for battery interconnects and is more than 4 times less resistive than nickel. Potentially all things being equal, a copper interconnected battery would potentially be a winning battery. In any ev, the battery is the heart of the system. With the least resistance of the battery pack, highest power levels will be achieved with less voltage sag and less heat generated by the pack.
We were provided with 2000 cells and set about individually testing the IR and storage voltage of each cell and chose those with the same voltage and lowest IR. It was a time consuming exercise to say the least. We also chose the cells with the highest storage voltage. Every little bit helps when it comes to batteries. In short, with such a build, we went to the nth degree to ensure the pack was as well put together as possible.
It was a privilege to be asked to build this battery pack and as such, we offered our expertise and materials pro gratis. We wish the team every success and will be keenly following their progress!
