Ford's New Charging System Lets Multiple EVs Connect To A Single Charger

Whatever the components used for the idea, Ford proposes various ways of charging multiple vehicles from a single charger, including distributed, waterfall, targeted, and automated strategies.

A distributed charging strategy would recharge each vehicle at equal rates, whereas a waterfall charging strategy would mean that the first vehicle directly connected to the charging station (hereafter referred to as the host vehicle) would get preference and would be recharged until full or until it reaches a preset level, after which the second vehicle would be fed, and then the third, and so on.

A targeted charging schedule would allow the user of the host vehicle to decide how much energy each of the dependent vehicles would receive. An automated charging strategy would allow the host vehicle to determine the amount of charge that each vehicle would get, presumably based on factors such as remaining charge/range, when each respective vehicle is connected, or what type of charging cord is used (assuming that there may be different sorts of cabling available). But there's another way that Ford envisions this system working.

The final charging strategy proposed here is called a pay-for-use charging strategy, where a surrogate vehicle would be able to jump ahead of other surrogate vehicles by paying a fee to the host vehicle. Hold your horses - we'll get to the various drawbacks soon enough.

This idea could be facilitated by the FordPass app or some other telecommunication module using Bluetooth, Wi-Fi, et cetera. With this, Ford hopes to incentivize the notion of shared charge support as a mini business model for EV owners.

We should also mention at this time that Ford envisions this whole host/surrogate charging system being compatible with a wireless charger too, which would effectively mean that one charging cable could be removed from the equation (that which connects the host vehicle to the original charging station).

There are several potential drawbacks of such a communal system. The first thought that springs to mind is that someone is charging their car at a shopping mall, for example, and returns to find that somebody else has attached their EV without consent. Another potential issue would be that the host vehicle is the only one that would pay, and that vehicle would get an exorbitant bill for recharging multiple vehicles, but both of these potential stumbling blocks are addressed by the fact that the FordPass app (or some other system) would be used to authenticate any leeching from the host.

A third potential hazard would be that a vehicle - whether the host or a first surrogate - would have its battery overcharged, which may lead to overheating, as the vehicles would be transmitting charge from the source, through the battery, and to a surrogate. Although not mentioned in the filing, it seems logical that Ford would find a way to prevent charge from continually flowing through the battery by means of a bypass system. That said, this could mean additional hardware and wiring, raising costs and weight.

We can also foresee problems with one vehicle in the chain leaving before the others do, which would mean that vehicle number three, for example, may need to move to reconnect to vehicle one, and if the host vehicle is fully charged shortly after a surrogate is attached, how would a leech be reconnected to power? Presumably, the FordPass app would notify this user, but it would still mean that the user would need to stop what they're doing to come and reconnect unless the user of the vehicle that departs is kind enough to close the loop again. Regardless, should the chain be broken, one may need to reauthenticate payment or leeching.

That queue-jumping option we touched on earlier also has an obvious fly in the ointment. Let's assume you're the first person to connect your EV to a host vehicle, but somebody who joins the network later gets preference because they paid extra. Would you be satisfied with waiting longer for your car to be charged? We doubt it.

For fleet managers, this seems like an excellent way of saving money on charging infrastructure. The targeted charging strategy seems especially useful as a way to maintain a good overall average state of charge for fleet vehicles, especially since a delivery van with loads of charge may get to the charger first while one with hardly any could connect to the network later. By allowing the host vehicle to automatically manage which vehicles are charged first or which get more charge, one could be confident that any vehicle connected in this human centipede-like network would have a reasonable range after being connected for a short while.

These same benefits could apply to households with only one charger in the garage but multiple family members using EVs. Say a teen arrives home from school first and plugs in. When their parents/siblings arrive home later in the day with various states of charge, all could connect and be assured that they'd have similar range in the morning.

Ford dealers - many of which will be required to install chargers - could also benefit.

Another benefit, which largely hinges on fellow EV users being considerate, is not having to wait for an EV charger to become available. You simply plug into the next vehicle in line.