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Old 01-01-2019, 06:34 PM   #1 (permalink)
Engineering first
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Join Date: Mar 2009
Location: Huntsville, AL
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14 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

17 Prime Plus - '17 Toyota Prius Prime Plus
90 day: 58.25 mpg (US)
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Plugshare trip planning has a trip planning tool to map routes, identify chargers and estimate trip time. Teslas already have a trip planning tool so this is for Leaf, BMW i3, and other EV owners. I will use my BMW i3-REx as an example for a pure EV trip from Huntsville to Nashville.
  • Start on a monitor with at least 1200 pixels wide and set the filter for the fast DC charger, CCS. Having a NEMA 14-50 EVSE, I also include it (See Fig 1.) Scroll down and hit “Create new” under “Trip Planner.”
  • Change the PlugShare car from BMW i3-REx to a BMW i3 and adjust range for the default 72 EV miles.
  • Calculate the kWh/mi by dividing usable battery kWh, 18.6, by range, 72 miles, or .258 kWh/mile.
  • If you have a fast DC charger port, measure the charge rate and convert to charge mi/hr. So the BMW i3 maximum rate, 40 kW, is 155 mi/hr.
  • Create a table of charged miles per hour for 208V at 16, 24, and 30 A, the maximum for the 7.2 kW BMW i3 charger:
    • 16 A is 12.9 mi/hr (3.4 min/%, 3:24 min:sec)
    • 24 A is 19.3 mi/hr (2.2 min/%, 2.12 min:sec)
    • 30 A is 24.2 mi/hr (1.8 min/%, 1:48 min:sec)

Entering my destination charger at the “Brentwood YMCA,” it drew an “Avoid Highways” route with a circle showing the EV range. The fast DC charger in Manchester TN disappeared from the range circle because the option “Show Along Route Only” meant Manchester was not close enough to display (See Fig 2.)

After disabling “Show Along Route Only,” the range circle included both the NEMA 14-50 at the Tennessean Truck Stop along I-65 and the fast DC charger in Manchester (See Fig 3.)

Clicking on the Manchester charger pop-ups the option to “Add to Trip” (See Fig 4.)

Enabling this charger draws the route to Brentwood but shows a red box warning “76.2 mi” on the Huntsville to Manchester segment. It is just over the rated 72 mi (See Fig 5.)

On a nice day without A/C or heating, driving the speed limit while using “ECO PRO” or “ECO PRO+” mode, the BMW i3 has just enough EV range to reach Manchester. Of course my BMW i3-REx has a gas engine in case the charge runs out. Fast DC charging in Manchester takes 40 minutes and costs ~$12 to get enough to reach Nashville.
  • “Total Distance: 138 mi About 3 hours 16 mins” of driving. “Total Time Including Waiting: About 3 hours 46 mins” trip duration, Huntsville to Nashville.

So I replaced the Manchester charger with the NEMA 14-50 at the Tennessean Truck Stop and allowed Highway routing by disabling “Avoid Highways” (See Fig. 6.)

The slower, NEMA 14-50 charge time, ~2 hours, cost $3. However, the shorter distance means more reserve range for each segment to deal with heating, A/C, or bad weather.
  • “Total Distance: 104 mi About 1 hours 50 mins” of driving. “Total Time Including Waiting: About 3 hours 50 mins” trip duration, Huntsville to Nashville.

Always check the charger user log before leaving as they can beak. Worse, many “J1772” chargers do not document reduced charging rates. For example UAH limits charging to 16 A and Blink is well known to limit charging to 24 A. When initially charging, check to see if the rate matches your expectation by noting the SOC, taking a 5-10 minute break, measuring the time, and the increased SOC. Be a friend and include this in your charging comment.

Bob Wilson

ps. Key trip planning options:
  • Show Along Route Only - with a distance slider, it shows just chargers along the plotted route for a detour to charge. Disabling allows larger (and longer) alternate routes.
    Show Range Estimate - with a distance slider, this draws a circle around the last, defined position. Adjust to match the EV range, 72 mi for early BMW i3-REx.
    Add Wait Times - using estimated charging times, an art in itself, it adds charging time to the driving time to get a block-to-block time. This is useful when deciding if an overnight motel stay makes sense or there are limited business hours at the destination.
    Avoid Tolls - save money for charging sessions. But toll roads can have limited charging.
    Avoid Highways - especially useful, this allows taking secondary roads to reach obscure chargers or taking shorter, more direct routes.
    Avoid Ferries - not many charging opportunities.
    Hotel/Lodging - with the block-to-block time, find a charging station near a bed.

2019 Tesla Model 3 Std. Range Plus - 215 mi EV
2017 BMW i3-REx - 106 mi EV, 88 mi mid-grade
Retired engineer, Huntsville, AL
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