"Minimum Charge" added to Value Charge on 300 mile SUV BEV

[jmueller065]

For Ford's new 300 mile SUV BEV they announced this week they should add a "minimum charge" setting to the value charge system.

Here is how it would work: https://spareelectrons.wordpress.com/2017/01/07/feature-request-for-fords-300-mile-suv/

 

[michael]

I would much rather they provide a maximum charge level as does Tesla.

My daily commute is about 80-100 miles. I would have loved to be able to set, for example, 60% maximum charge level. Again, plug it it, let it charge up. In my case a 240 mile car would range from 30 to 60% or so and NEVER fully charge. This is even easier on the battery than what your are requesting.


Chevy has slightly implemented this on the Bolt, providing 40% and 90% options in addition to full charge. Unfortunately, stupid EPA rules penalize the mileage rating if this feature is fully implemented. Chevy avoided the penalty by describing the limits as initial partial charge and hilltop reserve.

 

[WattsUp]

You guys both seem to be saying the same thing. Both asking for a custom "maximum charge" setting.

michael's example was charge to 60%. jmueller's example was charge to 33%.

jmueller wants the additional behavior that the charging occur only during the Value Charge window, or by a certain GO Time, but those are both mostly orthogonal issues.

 

[jmueller065]

jmueller's example was charge to 33%.

Not really my example is basically "if the battery is less than 33% full, then charge to full or however much can be charged in the value charge window. If there is more than 33% charge in the battery then don't charge at all."

I'm not sure which method would be easier on the battery:
Charge to 60% every night, or
Charge to full every 3rd night

Charging to 60% every night is similar to how a hybrid works: charge up to x% then discharge to y% (e.g. keep battery between x and y percent). As long as x and y are fairly conservative you're not working the battery that much (e.g. 60/30).

That vs letting the battery, over a few days, go down to x% then charging up to full (or nearly full).

Even so, though, depending on how much driving you did that day: Charging to 60% with a home level 2 EVSE will be difficult within the value charge window.

Think about it: FFE has 23 kWh for 70 miles, Bolt has 60 kWh for 230 miles, thus Ford's 300 mile SUV is going to have to have at least 70 kWh.

A 70 kWh battery will take a long time to charge at ~7 kW Level 2 rates (even 1/2 full will be something like 7 hours).

 

[WattsUp]

jmueller's example was charge to 33%.

Not really my example is basically "if the battery is less than 33% full, then charge to full or however much can be charged in the value charge window. If there is more than 33% charge in the battery then don't charge at all.

Oh I see.

Your approach is like "only charge (to 100%) after reaching a low water mark" (of 33% or whatever). This approach reduces the number of charges (to a degree proportional to overall usage -- i.e., charging frequency).

michael's approach is like "always stop charging after reaching a high water mark" (of 80% or whatever). The approach reduces the level of all charges (by a constant degree -- e.g., 20%).

Isn't the supposed best practice to never charge more than, say, 80% (or whatever) rather than ever fully charging?

 

[jmueller065]

Isn't the supposed best practice to never charge more than, say, 80% (or whatever) rather than ever fully charging?

Good question: I don't know; I had thought the best practice was to minimize the time at full charge.

Guess I'm thinking too much like an ICE driver now that I'm driving one (partially) again; treating the battery like a gas tank (only charge when the red light comes on).

 

[EVA]

It will be interesting to see what Ford decides to do to protect the battery. With the FFE they took all protection out of the user's hands and forced a buffer. You can't ever go outside that buffer. My guess, they will do the same thing with a higher range car. I would guess Ford has a lot of experience with stupid owners...or owners that don't think much or understand what should be done.

Tesla does a weird thing. You can set the car to charge after a certain time for a given location. For example, I have time of use electric billing. It is cheapest at roughly 11PM at night. Not a certainty, but that's the usual time. So I set my car to start charging at 11PM. When I plug my car in, I can choose from the dash - go ahead and charge at 11, or charge now. It is a one time setting. When I plug the car in anywhere else, it starts charging immediately (very much unlike the FFE that has some very confusing value charge stuff that doesn't necessarily work as intended).

The only other charging option is % of total battery capacity. The meter to set is really simple - they have an area that is Trip and the other is every day. The border is around 80% (there are no number on the screen, just tick marks).

The car ALWAYS charges to that level. It doesn't try to think about when will it be done, how much longer... all it does is dumb charge to whatever I set it. Super simple. A person can set it to whatever they want - 100% every day, or 80% every day, or 50% every day. Doesn't matter, the car charges to that level.

There is nothing called a Go time. No way to program the car to be ready at a particular time. You have to anticipate leaving and just turn the climate on with the app.

To get the battery all ready to go in winter weather, you have to set the car to say 80% charge overnight, then in the morning boost the charge to 100% and turn on the climate control about 30 minutes before you leave. The battery is still cold, and regen is still limited for some time, but it is better than a completely cold soaked battery.

The FFE is totally different. Even though I can't see how much real energy is being used over time (the Tesla has a run chart of time versus energy use - you can see when the battery is being heated because the dashboard energy use is far less than what is actually consumed as shown on the chart - 300 kWh on the dash versus 600-900 kWh on the energy chart) - I'm confident with Go times, the battery is mostly warm. That significantly reduces the initial energy use for cold morning driving.

I think you have to consider what Ford would do, first thinking protect the car from the user. Do everything in the world to prevent the user from abusing the car. Then go with what would be efficient.

It's kind of hard for me to imagine Ford will do much different on the 300 mile car. They have way too much experience with the C-Max and Fusion Energi cars, and some experience with the FFE. I would imagine more porting of what they've done than some new paradigm. Even though JMueller is totally right. And has the program they should use.