February 28, 20179 yr 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!
February 28, 20179 yr Nicely built battery, lots of attention to detail in that build ! But, I thought solar powered race vehicles were solely powered by the panel ?, if they are allowed a battery pack, surely the panel is just for show and its actually just an electric vehicle ?
February 28, 20179 yr But, I thought solar powered race vehicles were solely powered by the panel ? In the Solar Challenge long distance race, the batteries are just to accept the surplus from the panels when slow moving or going downhill. Solar dragsters are not allowed any battery. .
February 28, 20179 yr From the rules for 2017: 2.5 Energy storage A solar car may store energy. A standard energy storage system uses rechargeable electrochemical cells. Teams wishing to use some other form of energy storage must contact the event organiser. You are allowed 20 kg of Li-Ion cells
February 28, 20179 yr The machine you can see Jimmy using is worth in the region of £30K - He's only revealing a tiny amount of the attention to detail and resources poured into this project. A modest and talented, passionate man with quite a life-story!
February 28, 20179 yr The machine you can see Jimmy using is worth in the region of £30K - He's only revealing a tiny amount of the attention to detail and resources poured into this project. A modest and talented, passionate man with quite a life-story! Visited Jimmy today, yes a very interesting guy,with a fascinating history. His son told me that Jimmy was very successful as a rally driver when he lived in Cyprus, stilll drives his everyday car like he's stolen it to this day. A pleasant afternoon talking ebikes ,batteries etc. Over a nice cuppa.
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.