Delivery Boxes: BatteryBox

Boxes of the same size as an  OmniBox hold rechargeable batteries and are used to power the delivery vans.

Overview

These are the same size as the humble  OmniBox but bright red for danger to avoid you trying to unpack and eat the contents. They’re also too heavy to lift which means you’re safe even if you’re colour-blind.

Use

The BatteryBoxes are carried in the delivery vans to provide them with power. This overcomes the conflict of weight versus range that faces all electric vehicles. The range needed on a van differs from route to route and day to day. Any system with a single fixed battery is either struggling to get round without running flat or has power left and has therefore carried more battery dead weight around than it needed to and hence used more electricity than it could have done had it carried less battery capacity.

On a localnet delivery round, the route, payload, gradients and speed profile can be predicted very accurately before the van is loaded. The computer system can therefore work out how many BatteryBoxes are needed to ensure the van has sufficient charge to complete its round with some safety margin but is not needlessly carrying the weight of batteries it couldn't possibly need.

Impact

As the battery power can be spread around the van's payload area, a much simpler, lower and lighter chassis can be designed that is capable of taking one or several BatteryBoxes as needed.

As vans can be “recharged” simply by swapping one or more BatteryBoxes, the time it takes to recharge the boxes is no longer a real issue. A van can change its batteries and be ready to go out again as soon as the rest of its cargo has been loaded. Hence the optimum trade-off between charging time and number of BatteryBoxes can be chosen. This favours recharging by renewable sources as and when available and mains power overnight to make up any shortfall.

Charging and Connecting

These are sealed battery units which slide into the same racking systems that the  OmniBox and other containers use. They have several recessed metal contacts that let them take power from the rails they are sitting on or feed power to the rails. They therefore can be charged and used without connecting wires and use their own (substantial) weight to press the spring-loaded contacts home to make a good connection. With typically three contacts on each side and asymmetric profile to stop them being pushed into the rails the wrong way round, the contacts are both reliable and idiot-proof.

“Smarts”

The capacity of batteries changes over time. They lose efficiency and need to be replaced long before the chassis and mechanics of the van do. Many battery technologies work best and for longer if they are completely discharged on each cycle. Having multiple independent battery packs, each with an integral microprocessor tracking, reporting and controlling its charging and discharge history will help optimise the use of the batteries. For example, a van could discharge one box completely before drawing from the next. Only those boxes that had discharged would need to be unloaded and sent for recharging.

Location

Although batteries can be stored in the payload area of the van, the size chosen also happens to fit nicely under a row of seats. With a bench seat across the front of the van, it’s possible to open both doors and slide a new set of batteries in, pushing the dead ones out the far side.

Electric Car Pool

The same battery unit could be used in the hire cars/vans that are rented out from the hubs. A shared pool of BatteryBoxes would be most efficient and allow these cars to benefit from many of the benefits described above. In particular, hirers could choose to trade-off boot (”trunk”) space versus range. They would also be able to stop at any LocalHub on their route to swap one or more BatteryBoxes for fully charged ones and continue in a matter of a minute or two.

Refurbishing

A major challenge with battery packs for vehicles is that their capacity drops off after a number of charge/discharge cycles. The intention here is that the “naked” cells within a BatteryBox could be replaced if they wear out before the box itself does - allowing the box to re-enter service with a new set of cells in it. As the battery technology will have progressed during the life of the original cells, the box should be even better next time around than it was when first manufactured.

Fuel Cells

A well-designed outer casing and monitoring processor could even allow the contents of the box to be replaced by alternative power sources - such as fuel cells - when these become economically viable.