Bingo Fuel

Feature image courtesy of Volkswagen Ireland.

Bingo fuel is an aviation term of art for the amount of fuel required for a safe return to base and landing. When an aircraft reaches bingo, the pilot must abandon the mission and return to base (usually the designated bingo destination) to ensure that the crew and aircraft will be available to fly another day.

A similar notion is useful in automobile trip planning and fuel management. In internal combustion vehicles, we never really give bingo fuel any thought. When the little orange light comes on, buy fuel soonest. Unless driving out in the country, we were always within a mile or two of a fill-up. Not so driving a BEV. Continue on to learn how the Dismal Chauffeur manages BEV fuel.

References

1. VW ID.4 Owners Manual, Charging the High Voltage Battery
2. https://electrek.co/2016/09/06/aaa-ev-emergency-charging-truck/

Am I likely to run out of energy?

Reference [2] reports that road service calls to recharge BEV traction batteries are rare. AAA added Level 2 chargers to a number of its roadside assistance fleet and did have some calls for roadside recharging. But most drivers practice good voyage management including planning of rest and DC fast recharging stops with primary and alternates within reach.

Kyle Conner, Out of Spec Reviews presenter, routinely goes car trekking without planned charging stops. He plans his stops on the road, usually before setting out on the day’s leg or at a planned stop. Conner plans for margin to drive to an alternate charge point should the primary be tango-uniform (broken).

VW Charging Recommendations

VW recommends maintaining the battery between 20% and 80% charge. This interval provides enough energy for several 30 mile days around town and leaves enough reserve in case life mandates an unplanned doctor or vet visit. It also works well for road tripping as charging from 80% to 100% requires as long as charging from 10 to 80 percent. The charger uses a finishing protocol above 80% to equalize individual cell voltages. So 20 to 80 at home and trekking.

Note that we have few if any DC fast charging stations in town (Norfolk, Virginia) that are not Tesla-only. So we must plan to charge at a Level 2 AC charge point, most likely a home EVSE or a Tesla Destination charger.

So, What is Bingo?

I use 50 miles as a bingo level. If I arrive home with less than 50 miles of energy remaining, I charge the battery that evening. Fifty miles is about 20 percent of capacity. If I must go out, I have 30 miles of travel in the can, enough for a local urgent errand.

Charging Lineup

Reference [1] gives the charging procedure and explains setup of the vehicle for immediate charging.

Scheduled Charging is coming, coming, coming …

Scheduled charging is partially implemented. An over the air update is promised to provide full IEC charging management later this spring.

As of 2022 New Year’s Day, the vehicle will do the immediate part of a charge schedule but will likely go to sleep (turn itself “off”) and remain asleep through the delayed charging start interval. You’ll return in the morning to find a partially charged vehicle.