Electric 3-wheeler Rickshaws are the most economical among battery powered electric vehicles. They cost INR 1,20,000 (USD 1615) to buy, including the price of a 48V100Ah deep cycle battery @ INR 20,000 (USD 270) and run around 80 KM on a single charge. No wonder there are already 15,00,000 E Rickshaws in India alone. These E-Rickshaws use Lead acid tubular or flat plate batteries, which cost less than half the price of an equivalent Lithium Battery & have a service life of around 600-800 cycles of 80% discharge & recharge if maintained properly. However, with conventional chargers, the Lead Acid Batteries require 6-7 hours for 80% recharge and 10 hours for a full recharge after a discharge of 80% of rated capacity. Faster recharge increases battery temperature, copious gas evolution & reduces its life. This has been a disadvantage for lead acid batteries in EVs. Lithium-Ion battery requires 2 hours for 80% recharge and 3 hours for a full or recharge. The objective of the research work was to try out and develop a charger, which can fast recharge E Rickshaw battery up to 80% of capacity in lesser charging time without increasing battery temperature or gassing, avoiding battery service life reduction. Method of fast charging was to continuously explore the charge acceptance limits of battery and feed it with optimum charging current so as not to increase temperature & gassing. The unique fast charger requires only 3 hours & 30 minutes to recharge the battery to 80% of its capacity, while temperature rises by 3°C to 4°C, less than half of that in normal charging process. In addition, a super-fast “opportunity charge” during one-hour lunchtime, injects 35% energy in 65 minutes, giving E Rickshaws an extra 35 KM run each time. It is proven that service life is same or more. The fast charger prototypes were successfully field tested on 40 vehicles each at Kolkata & Baharampur in West Bengal, India, to the entire satisfaction of the E Rickshaw drivers. It is now in mass production & sales. Lead Acid batteries in E-Rickshaws, E- Bikes, golf carts & electric trucks are discharged and recharged daily or more. A safe & fast charger increases productivity & revenue.
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