Planning A Long Journey With Your Chevrolet Bolt EV or Opel Ampera-e?
A general rule of thumb is that you will need 30-60 minutes of DC fast charging to go 75-125 miles (120km to 200km) in your new Chevrolet Bolt EV or Opel Ampera-E.
This number may be significantly different than what your Distant To Empty (DTE) gauge, or “Guess-O-Meter” (GOM), might display since GOM estimates are based on prior driving consumption and can vary wildly in some cars, including the Bolt.
Not all cars will have the required DC fast charging port, as it is an extra cost option.
This might be counter intuitive to folks not used to an EV, but the fastest drive between two points is not filling up the battery at each enroute stop. Quite the opposite, since charging above 65% in a Bolt EV will significantly increase your charging time due to the reduced speed with which the battery can accept a fast charge above 65%.
Also, if you are using the fastest 125 amp “50kW” chargers, don’t drive slowly between charging spots to save energy. Drive normal freeway speeds of 65-75mph (105km/h to 120 km/h) to get the fastest overall speed in your journey. Above 75mph is not recommended, due to the relatively poor aerodynamics of the Bolt EV.
The Bolt EV will charge at an average speed of about 42kW at 125 amps while charging from 15% to 65%, which adds about 21kWh into the battery in about 30 minutes, and 30kWh in 45 minutes.
Using 2.5 miles is added per minute at 42kW, while beginning the charge at 0% to 20%, will result in:
*75 miles / 120km added in 30 minutes (42kW average at 125 amps)
*110 miles / 175km added in 45 minutes (charge rate may slow slightly)
*125 miles / 200km added in 60 minutes (charge rate slows significantly)
To add 238 EPA miles / 380km of range would require well over two hours of charging and is not recommended for enroute charging unless there isn’t another DC fast charger (or your destination) within range.
Obviously, the actual range is dependent on how fast you consume it, but we are assuming normal freeway speeds in nice weather on mostly level roads using an average consumption of 3.6 miles per kWh (277 Wh per mile) / 5.75km per kWh (174 Wh per km).
Again, to have the lowest overall travel time, it is not advantageous to drive slower to get improved energy consumption, since the fast chargers can upload power so much faster than you can consume it.
Cold weather, cabin heater use, wind, sustained high speed, hills, mountains, rain, snow, low tire pressure, etc, all adversely affect range and increase energy consumption.
EVgo network chargers are all on 30 minute timers. To add 125 miles will take about an hour (again, if starting at 0% to 20%), and you need to interrupt your lunch or coffee break to swipe your EVgo card every 30 minutes. Fortunately, most other networks are on 2 hour timers. Charging above 65% will severely reduce the charge rate, and is not recommended, unless absolutely needed to reach the next charger, destination, or to compensate for adverse weather conditions.
Sure, when you leave your home or hotel, charge up all the way to 100% if you want to. But, you really want enroute chargers to be about 75-125 miles apart for the lowest overall travel time.
The car will charge the fastest from 0% to about 65%. The strategy is to burn down the battery at your first charge location to 10-20% remaining (or lower, if you are adventurous) and then charge for 30-60 minutes to add 75-125 miles of range each time.
In addition, you really only want to use the fastest chargers, and those that are the best are the ones that are 125 amps.
ABB, Signet, Efacec, Tritium and others build fast DC chargers that are 125 amp capable, and may be labeled by their network in the USA as either EVgo, ChargePoint, Greenlots, OpConnect, etc. Of course, you’ll want to have established accounts with each of the networks you plan to use.
The BTC chargers used at some locations by the EVgo network are only 100 amp capable, making your charge time increase about 25%.
The stand-alone CCS ChargePoint units (they won’t have a CHAdeMO plug on them) are only half power (60 amps), so I would avoid them like the plague. They will DOUBLE your charge time, and are really only useful if there is no other option.
With a little experience, you’ll be arriving at chargers with a low battery %, which is why it is wise to pick locations with more than one charger. Just one charger at a location could be broken, vandalized, busy, blocked, etc, and a low battery % limits your options.
Use PlugShare to verify that folks are not having recent problems with the charger(s) at your planned stops. Be sure to filter for “CCS” only.
If the Bolt EV were sold in Japan, it would have to have CHAdeMO, just like both the BMW i3 and Tesla (with a Tesla supplied adaptor). The Bolt EV cannot currently use CHAdeMO or Tesla Supercharger DC fast chargers, nor can it use GB/T in China.
Obviously, this planning only works mostly in the west and east coasts of the USA where there is adequate charging infrastructure, but it works almost everywhere in Europe and U.K.
So, in summary, plan your trips with chargers that are 75-125 miles apart, only charge enough to get to the next charger that is 75-125 miles away plus about 10-20%, and so on. This will take 30-60 minutes on the fastest 125 amp “50kW” chargers. Bump up your reserve to 30% or more in adverse weather, or climbing hills.
Try not to charge over 65% unless absolutely required. Use the fastest chargers rated at 125 amps, and plan to find locations that have more than one charger, or another nearby charger in case they are blocked or broken. Get whatever accounts, cards, apps, or fobs that are required by the various networks. Don’t forget to enjoy the trip!