when to charge battery?

[Stevepkam]

Is it better to recharge everytime you can or to wait until the battery is totally discharged? I have a 2019 Ford Fusion Energi. thanks for your help.

 

[murphy]

The battery is never "totally discharged".  There is only one battery.  When the EV reads zero that means it has dropped into the hybrid portion of the battery. 

 

I charge my battery when the car is put into the garage.  There is a contingent on the forum that are protecting the battery for the next owner.  They don't charge to 100%.  They don't use it at all in the summertime.

 

I bought the car to use, not save it for the next owner.  You will have to decide which group you are in.

 

Oh and 100% is not really 100%.  It is whatever Ford was comfortable charging it to.  It is generally believed, from using OBD2 scanners, that 100% is about 95%.

 

[theterminator93]

Li-ion cells, as a rule of thumb, degrade quickly when at high temperatures and SOC. They also die permanently if the cell voltage falls too low.

 

With a Li-ion battery stored at 100% charge, high temperatures cause permanent degradation rather quickly - and dropping a full kWh over a year (or less) is definitely not a great way to inspire the buyer to purchase a generation of hybrid/electric vehicles. By purposely leaving the maximum charge permitted a few percent below the true full charge limit, the rate of degradation drops dramatically. Keeping the battery at hybrid-only levels nearly negates high-temperature permanent capacity loss that would happen most often in the summer which is why some people choose to do that.

 

Like all batteries there's a specified rate of self discharge. If the battery was allowed to drain to a "true" 0% and then sat unused and uncharged for a long enough period, there is a risk of the main battery charge level dropping to dangerously low voltages which would then permanently "kill" cells within the battery pack.

[j8048188]

I charge my car a max of 1 time each day/night to avoid excess heat and strain, and I prefer to not keep the car fully charged and sitting for days plugged in.

When I park at night I look at my state of charge and plans for the next day. If I'll be driving a lot, I'll plug in. If I have no plans to leave the house, I'll leave it unplugged, and plug it in the night before I leave the house again. Keeping a battery charged at a full 100% will degrade it faster than if it is stored at a lower charge.

 

Once I started limiting charge on my cell phone to a max of 80%, I found the battery keeps it's full capacity for a much longer time (I've had my current phone for a year now and the actual capacity is still 98% of the design capacity. My previous phone, after 2.5 years, still had 85% of it's design capacity. The last phone I used before starting the battery charge limit had about 50% of it's capacity after 2.5 years.)

[Ffe]

Interesting.  I was originally planing to always plug in ASAP when I got home.  Just because I always wanted to be at the ready to do as many miles on electric as I could.

 

But now I'm wondering.  Should I charge to some threshold say, 80%  when I get home.  And then schedule it to charge up to 100 right before I leave?  i.e.  IF I can predict and schedule exactly when I depart, is it best to reach 100% displayed (95% actual) charge immediately before getting on the road?

 

In reality I'd probably pick a level that I know I can go from that to full in ten minutes.  Then say, when I get out of the shower, I press a button and it reconnects charging  so that it tops off just before I get in.

 

How to get charge level out of the car.....  Do PHEVs like the Energi, communicate this SOC to the charger by chance?

[murphy]

The 12 volt battery is charged after the HVB reaches 100%.  If the 12 volt is low and you don't charge to 100% you may find the 12 volt dead some morning.

I don't have TOU power billing.  My fee is the same 24/7.  I always charge when I pull into the garage. 

 

IMHO if Ford felt it was necessary to charge to lower levels the y would have provided the ability to do it automatically.

 

The charger is built into the car.  The thing on the wall is called an EVSE (Electric Vehicle Supply Equipment).  It is basically a smart switch that turns the AC on and off. 

 

 

[Ffe]

Gotcha.  Are all generations of Energi equipped with the same kw rating of charger?

 

I've noticed that there's several different amperage levels of EVSEs, and i know there's no sense in buying one that can supply more amps than the car's internal charger can use. 

 

I wonder if any EVs have considered using higher voltage supplies to reduce conductor size in the cord and still push a lot of watts.  A lot of commercial buildings have 277/480 for instance and i would bet that all the hv wiring has 600v rated insulation anyway.

 

Where i work there's no 240, just 120/208.  Will fusion charge slower on 208, or is that likely to blow it up?  I will probably install a charger at work, and if L2s require 240 not 208, or 208 charges slower then that's worth considering.

[murphy]

The most an Energi will draw is 16 amps at 240 volts.  I doubt that the charger in an Energi is capable of handling a higher input voltage.

I have no idea if it can handle 208 volts but since it works at 120 or 240 it might.  The charger in the car has to convert AC to DC and multiply the result up to a value high enough to charge a 350 volt battery.

 

The new Mustang Mach-E has a CCS connector that allows direct DC charging.

 

I can charge my Tesla at 240 volts 80 amps AC.  It also takes direct DC charging at a Tesla Supercharger.  It has a 400 volt battery.

 

There is one advantage to using an oversized EVSE.  It will have heavier wire which means less voltage drop.

 

I have 3 EVSEs in my garage not counting the ones that come with the cars.  Leviton 16 and 40 amp plus a Tesla 80 amp.  This was a result of not thinking ahead.

In 2013 I bought the Leviton 16 for my 2013 Enegi.  In late 2014 I bought a Leviton 40 for a 2014 Tesla.  In 2018 I bought a Tesla 80 for a 2016 Tesla.

 

It also meant running the power to the garage three times.

 

Charging is not at a constant current.  As the SOC increases the current has to decrease because going over 100% is a very bad thing for a Li-Ion battery.

 

I use the analogy of holding a beaker in your left bare hand and pouring a strong acid into it.  The penalty for overfilling the beaker is severe.  You end up dribbling the acid in at the end.

 

 

[jsamp]

On 3/1/2021 at 1:10 PM, Ffe said:

Interesting.  I was originally planing to always plug in ASAP when I got home.  Just because I always wanted to be at the ready to do as many miles on electric as I could.

 

But now I'm wondering.  Should I charge to some threshold say, 80%  when I get home.  And then schedule it to charge up to 100 right before I leave?  i.e.  IF I can predict and schedule exactly when I depart, is it best to reach 100% displayed (95% actual) charge immediately before getting on the road?

 

In reality I'd probably pick a level that I know I can go from that to full in ten minutes.  Then say, when I get out of the shower, I press a button and it reconnects charging  so that it tops off just before I get in.

 

How to get charge level out of the car.....  Do PHEVs like the Energi, communicate this SOC to the charger by chance?

 

The less time your battery spends at 100% the better.  I rarely charge to 100% and mostly do so with "value charge" so it reaches full when I'm about to leave.  That said, you don't need to fret over 1/2 or 1 hour spent sitting with a full battery.  It is when the car sits all day at full, and the temperature climbs significantly from when it was charged that damage can occur from an overcharge situation.  If the car is going to sit for significant amounts of time, keep the SOC below 80% (one study says 70%) .

 

"topping off" will take more than 10 minutes from 80%, but on L2 can be done fairly quickly, < 20 minutes. 

 

Yes, that conflicts somewhat with what murphy is saying, and we can disagree on that.  I typically only charge to 80-85% unless I need it all for a specific trip.  My battery condition (~3% degradation in 80K miles) tells me that has been a wise move.

 

[Ffe]

On 3/2/2021 at 5:46 AM, murphy said:

The most an Energi will draw is 16 amps at 240 volts.  I doubt that the charger in an Energi is capable of handling a higher input voltage.

I have no idea if it can handle 208 volts but since it works at 120 or 240 it might. 

I found some local "charging stations" in my area that are "flagged" in chargepoint as being 208v and warning that they're slower than 240v stations.  They're outside a GM plant, so I doubt they routinely smoke cars there.  But I have broken a power supply once before that was good for 120/240 by giving it 208v.

 

Some hardware, draws constant wattage, so 208v was high enough that it auto-switched from 120v to 240v circuitry, but because of the constant wattage, it pulled more amps than it was rated for, and the smoke came out!  I work in IT systems administration and MOST hardware I come across that accepts 120 and 240 (auto-sensing) these days, actually accepts 100-250VAC 50/60HZ. That sets it up to work in like 98% of every country on Earth.  Cars (being inherently less portable than laptops) probably don't need to be so accommodating.  (You're not going to import, let alone drive, your US Fusion to Japan or Germany.)  So I'd try to find a spec sheet on the onboard charger before getting to wacky with mine.

 

I'm curious though, if you know if ALL years of the Energi max out at 16A/240V or if its just one specific year you know that about.  Or particularly the 2016 , 2017, 2018, and 2020.

 

On 3/2/2021 at 5:46 AM, murphy said:

I can charge my Tesla at 240 volts 80 amps AC.  It also takes direct DC charging at a Tesla Supercharger.  It has a 400 volt battery.

Can any EV you know of, equipped to accept AC with its own rectifier and DC direct to the cells, accept both concurrently for a faster charge, utilizing all available hardware to the fullest?  I know Tesla's plug has only two current carrying conductors and it probably uses contactors to direct DC and AC appropriately.  Then again, I believe it's theoretically possible to transfer AC and DC current across the same pair of conductors concurrently, but I doubt it buys you any headroom in the ampacity of the conductors

 

On 3/2/2021 at 5:46 AM, murphy said:

There is one advantage to using an oversized EVSE.  It will have heavier wire which means less voltage drop.

That, and safety margin, are the reason I ran 10-3 wire from my panel to my new Fusion's parking spot.  I'm going to use a double-pole 20A breaker, and a pair of nema 5-20 outlets next to a 6-20 in a double-gang box.  So I can have two beefy 120v circuits if I need to for something garagey, or one 6-20 for EVSE.  Frankly I'll keep the EVSE plugged in indefinitely and just remember not to be using it when I get out the table saw.

 

Now I'm wondering should I splurge and make that 20a double pole breaker a CAFCI, or just regular.  I do kind of want to add extra protection for this being the soow cable will see a lot of flexing over the years.  Probably get run over a few times.  I've already dropped the EVSE connector once, though I intend to have it ceiling mounted long term and normally wound up so that it can't touch the floor.  I'll refer to code before I buy it of course, but I care more about safety then NEC.

 

On 3/2/2021 at 5:46 AM, murphy said:

I have 3 EVSEs in my garage not counting the ones that come with the cars.  Leviton 16 and 40 amp plus a Tesla 80 amp.  This was a result of not thinking ahead.

I'm probably going to intentionally get a cheap-ish 16A EVSE.  I'm not the sort of guy to buy Monster Cables (TM).  Though I'm leaning towards an Amazon one that is dual voltage (Level1 & 2 combo) with a quasi bootleg looking adapter.

https://www.amazon.com/dp/B075GJK2S9/ref=ord_cart_shr?_encoding=UTF8&psc=1&smid=A2L77EE7U53NWQ

 

It strikes me as potentially useful that it can do 120 and 240v in the same device.

 

Can the slower 120v charging possibly be 'gentler' on the battery than 240v charging?

 

Is the square-ish evse that ships with the 2018 and later model-year actually dual 120v/240v capable?  Is anyone here successfully using their 2018 Ford convenience charger that way with a bootleg 5-15-to-6-20 adapter who could share the model number of their ford convenience charger or photos of the label to give me some confidence in it?

 

The 2018 Ford Convenience Charger

does look obviously like the dame thing as the clipper creek that's sold in 120v and 240v plug types:   at https://store.clippercreek.com/residential

I've read reports that the circuit boards are the same.  And I totally believe it.  Why reinvent the wheel eh?

 

Also worth asking, what's my risk level if I have access to an ungrounded (but GFCI protected) outdoor nema5-15 at work?  the 2017 edition Ford convenience EVSE (white handle with cord reel) worked fine on that outlet.  But the 2018 detects the bum ground and balks (gasp).  I can obviously make a ground-via-neutral adapter to trick out the EVSE.  The GFCI should (and indeed is often used per code to) protect me from leakage.  Is there any special reason why the chassis might need to be earth grounded during charging separate from the neutral?

 

If the neutral lost connection, the gfci would prevent a hot chassis, and the EVSE's relay I'm certain, would disconnect both poles of the output if it couldn't power on.  I guess it would leave ground connected, so if something else on that circuit caused neutral to float hot then it could be liven up the chassis but if it's all downstream of the gfci then it should be safe.

 

I'm more asking, as regards the function of the EVSE, is ground used in any way as part of the charging process as designed?

 

On 3/2/2021 at 5:46 AM, murphy said:

It also meant running the power to the garage three times.

I'm the first owner of my home, and I very much regret not having a conduit or raceway built into my house from basement (with the service panel) too the attic.  I've ran cable (mostly cat5e) through the one deadspace that exists in a triangular corner junction of walls in the first floor.  But it would have been so nice to have purpose built raceways.

 

On 3/2/2021 at 5:46 AM, murphy said:

Charging is not at a constant current.  As the SOC increases the current has to decrease because going over 100% is a very bad thing for a Li-Ion battery.

I use the analogy of holding a beaker in your left bare hand and pouring a strong acid into it.  The penalty for overfilling the beaker is severe.  You end up dribbling the acid in at the end.

Lovely imagery!  Communicates the point very well!  Lithium smoke would not be something I want to smell.

[theterminator93]

18 hours ago, Ffe said:

I'm curious though, if you know if ALL years of the Energi max out at 16A/240V or if its just one specific year you know that about.  Or particularly the 2016 , 2017, 2018, and 2020.

 

Now I'm wondering should I splurge and make that 20a double pole breaker a CAFCI, or just regular.  I do kind of want to add extra protection for this being the soow cable will see a lot of flexing over the years.  Probably get run over a few times.  I've already dropped the EVSE connector once, though I intend to have it ceiling mounted long term and normally wound up so that it can't touch the floor.  I'll refer to code before I buy it of course, but I care more about safety then NEC.

 

Can the slower 120v charging possibly be 'gentler' on the battery than 240v charging?

 

Lithium smoke would not be something I want to smell.

 

I can't respond to all your points, but as a fellow IT administrator... I can tell you from experience that lithium smoke not only stinks, but it burns the eyes.... ?

 

I don't think the 2017 has a higher charge rate limit, given the dash readout of the 240v charge time being consistent with ~2x the charge rate. Maybe so with the 19-20s and their larger battery though?

 

I've got plans to pull either 10/3 or 8/3 to the garage in the next few years for a 40 or 50A charging station for potential future BEVs we will likely own. A CAFCI might not be a bad idea in the long run. NEC will probably require them in a number of years anyway.

 

As far as faster charging vs. slower charging's effects on the battery, yes. The slower charging lends itself to less permanent battery degradation. This is because the heat generated by the charging process is not only is being generated at a slower rate, but also has more time to dissipate. However, the AC-DC conversion is more efficient when using 240V, so you will put less energy in to the car from the wall outlet to do a full charge when using 240 than you would with 120.

Edited March 12, 2021 at 11:07 PM by theterminator93

[Ffe]

What I don't like about CAFCI's is being more likely to trip, and having to go to the panel to reset them.  And I can't really use a 'outlet local gfci' for this.  I've never seen a nema 6 or 14 gfci anyway.  Maybe some day those fancy new smart panels will be the norm and I'll be able to reset my breakers by replying to my service panel's tweets.

 

I'm wanting to know if all Fusion Energi's are cable of the same maximum input wattage?  Around 7kw right?

 

It makes sense that 120v wastes more energy during charging.  I'd be interested in 'throttling' my 240v charging then.  to only draw say, 2 or 3kw at home.  As long as the efficiency doesn't go down.  I have per-circuit electrical usage monitoring at home thanks to a TheEnergyDetective system I put in years ago, so I could legit measure this over time.

 

What about giving it 20 minute bursts of 240v charging with 10 minutes rest between to dissipate heat?  May not be worth the extra weat it puts on contactors though.  I think it would super if I could use part of the charging control circuit itself to limit the charging wattage, so I could stay at the more efficient 240v, but be gentler to the battery.  Only go full speed if I'm close to needing to leave.

[murphy]

12 hours ago, theterminator93 said:

 

 

I've got plans to pull either 10/3 or 8/3 to the garage in the next few years for a 40 or 50A charging station for potential future BEVs we will likely own. A CAFCI might not be a bad idea in the long run. NEC will probably require them in a number of years anyway.

 

 

To charge at 40 amps you need a 50 amp circuit because of the 80% rule for continuous loads.  80% of 50 is 40.  A 50 amp circuit needs to be wired with 6 gauge wire.

[theterminator93]

Yes, absolutely - in fact I have 6/3 and the needed 50A breakers and outlet on my list for when the time comes. Thanks for pointing out I had the wrong AWG's listed for those currents.

[j8048188]

My car has charged very happily at several 208V stations.

[Ffe]

I should update, I've been happily driving my Energi now for over a month and about half of the stations here are 208v, half 240v.

 

The 240s are a little quicker, I think, but both work fine.

[jsamp]

Nobody really answered the question(s) about charge rate.  The Energi has 2 charging rates: 120V@12A (1.44 kW) and 240V@16A (3.84 kW technically, but Ford lists it as 3.3kW which assumes 220V@15A).  The only way to do less than that is if your EVSE has controls to do less amps that those two.  The car and EVSE do a handshake to determine what each can deliver/take, and they agree on the amount before charging commences.

Edited April 15, 2021 at 04:35 AM by jsamp

[Ffe]

In my city it's hard to find 220v.

 

I've been using odb2 to monitor my charging and i have found "available battery charger input" to be listed via odb2 to be:

3.80kw when charging on a 240 V AC outlet.

3.35 at 208-209V AC

3.30 at 206-207V AC. 

1.35kw at 115 v

 

I even found one charger in town that odb reported 3.25 kw at 204v.

 

So it looks to me like amperage is the limiting factor.  Odb 2 usually reports a 13 amp AC input on 240 volt charging stations and a 15 amp AC input on 208 volt.  On 120v with the charger that came with the car, 11A is that obd2 shows as the input current.

 

So I'm guessing the charger first tries to auto detect which of the three common ranges of voltage its using and assigns a max amperage its willing to draw.  Then it draws that amperage exactly, and any variation in voltage will thusly affect how many kilowatts it can used for charging and how fast that charging goes.

 

The station I found that was 204 volts is a single station by itself far from the building that supplies it so I suspect it has some voltage drop.

 

 

 

 

 

 

 

 

 

[murphy]

5 hours ago, Ffe said:

In my city it's hard to find 220v.

I

The voltage standard in the USA has been 120/240 for at least 75 years for any utility that is connected to the GRID.

208 means that it is derived from a 3 phase system which is usually only found in a commercial environment.

I have never seen 3 phase power in a residential area.

 

[Schleeb]

On 3/12/2021 at 3:05 PM, theterminator93 said:

I had no 220V service in my garage so I had to have it pulled from my breaker panel.  Had to replace the beaker panel as well (Zinsco) for a modern one.  Cost me about $4500.  The electrical people said if I was using it to power my Level 2 charger a GFCI breaker was required.  Since I also wanted to occasionally use this new outlet for my TIG welder they also told me that the GFCI may not like the welder and it may trip out.  Since then I've tried my welder using TIG mode (AC and DC) and conventional stick welding (AC and DC) without any issues.  It was a brand new modern welder, not the typical AC/DC stick welder.

 

I can't respond to all your points, but as a fellow IT administrator... I can tell you from experience that lithium smoke not only stinks, but it burns the eyes.... ?

 

I don't think the 2017 has a higher charge rate limit, given the dash readout of the 240v charge time being consistent with ~2x the charge rate. Maybe so with the 19-20s and their larger battery though?

 

I've got plans to pull either 10/3 or 8/3 to the garage in the next few years for a 40 or 50A charging station for potential future BEVs we will likely own. A CAFCI might not be a bad idea in the long run. NEC will probably require them in a number of years anyway.

 

As far as faster charging vs. slower charging's effects on the battery, yes. The slower charging lends itself to less permanent battery degradation. This is because the heat generated by the charging process is not only is being generated at a slower rate, but also has more time to dissipate. However, the AC-DC conversion is more efficient when using 240V, so you will put less energy in to the car from the wall outlet to do a full charge when using 240 than you would with 120.

 

[Schleeb]

I had no 220V service in my garage so I had to have it pulled from my breaker panel.  Had to replace the beaker panel as well (Zinsco) for a modern one.  Cost me about $4500.  The electrical people said if I was using it to power my Level 2 charger a GFCI breaker was required.  Since I also wanted to occasionally use this new outlet for my TIG welder they also told me that the GFCI may not like the welder and it may trip out.  Since then I've tried my welder using TIG mode (AC and DC) and conventional stick welding (AC and DC) without any issues.  It was a brand new modern welder, not the typical AC/DC stick welder.