Who was never shocked by millions of people driving alone in their family car  going to work every day? The following invention can be a beginning of an answer, but not only.

In most hybrid vehicles of series-parallel or parallel type, the main purpose of the electric propulsion chain is to increase the efficiency of the thermal propulsion chain. Generally, the best efficiency is not met at the maximum electric power. It means that the electric chain is not continuously used at its maximum capacity. The remaining capacity makes it possible for a second additional battery to participate to the vehicle propulsion.

The particularity of this second battery is to be releasable thanks to a simple system, entirely integrated into the vehicle and which comprises:
• A means for the vehicle positioning which can be the existing system for parking assistance,
• An electric jack integrated into the vehicle and able to lift the battery even with a position offset,
• Some arrangements under the vehicle floor for the battery guidance, connection and failsafe locking.

The figure shows the electric jack which can oscillate around vertical in order to compensate the positioning gap. The jack rod has a gripping head with two stable positions (first push: the battery is griped; a second push: the battery is released; same as a ball pen's mechanism). A 100 Watts motor is sufficient to lift a 250 kg battery in few seconds. As it is rarely operated, the associated gear reducer can be as simple as the press fruit one.

How is it used?
• For working days, the solitary driver can consume more electric energy coming from the national electric grid which is a cleaner and a cheaper energy, thanks to a second battery which can be a “plug in” battery.
• For holidays, all the family is on board with heavy luggage while the driver is not sure to find a fast battery charger on its way. So it is better to keep the second and weighty battery at home.

What is behind?
The vehicle can be designed for one person plus the second battery and for five persons without the second battery. So the vehicle is no longer designed for five persons plus the second battery. For safety, MCU can detect an unexpected overload and reduce vehicle performances accordingly. Consequently, we can cut the laden weight up to 400 kg with induced weights!!! In addition, it’s more economic and more ecologic.

This system can also be used for electric vehicles, or at some other ends: battery hiring, exchange, adaptation, maintenance….

Legend: 1 soil, 2 battery, 3 vehicle floor, 4 jack, 5 elastic support, 6 gripping head, 7 conic guide+ air cooling connector, 8 female electric connector, 9 male electric connector, 10 emergency switch, 11 articulated protective covers, 12 failsafe locks.