The Potential Pitfalls of Electric Cars

If electric, water, sewer, natural gas, cable/telephone, and even steam can be run to buildings in a city, then electric can be run to curbside chargers. It just takes a willingness to do so. Until that happens, fast DC charging can fill the gap. That is what most in Japan do, since many home electrical supplies charge slower than our Level 1.

But how much more will that cost than 120kW? Some locations will require energy storage(batteries, capacitors, flywheels) of some type to be a buffer, or charging rates will be throttled back by the supply speed.

Is the compressor also supplying heat? If just A/C, that mostly runs the compressor during the day. Car charging mostly occurs at night.

 

I think those are bigger challenges (not pitfalls) of EVs than range and speed of charging. I see how range and speed of charging will keep improving, but the street parking situation in cities will only get worse. How would you serve those drivers as far as energy for their cars if they are all EVs? Those people will have to go to a public charging station once in a while and spend some time there. No way around it. Again, with improved range and charging time that will become less of an issue. So, not a pitfall. But definitely a challenge.

 

Just heard the comment "Electric utilities are waiting with bated breath for EVs because their customers are using less power due to solar and other alternate power sources, so they need a new customer base". This was broadcast on radio.

Kind of kills the worry EVs will overload the grid I suppose.

 

Utilities in our area love EVs. For exactlythat reason.
The ones I know ofare also working hard, and quickly (for Utilities) to implement smart charging such that EVs can be load balancing tools.

 

So will partial charges shorten battery life or lower battery capacity? I notice my battery shows max EV miles (27.4 this AM) 20 or 30 minutes before the charge is completed. Also another odd thing happened . . . when I went to unplug this AM there was still 20 minutes showing to complete charge. The charge should have been done at least 2 hours earlier. (Using 110 outlet at home.)

Must be durability issues for manufacturers to slow down to nearly a trickle close to completion. Said 3.94 amp draw with 20 alleged minutes to completion yesterday at an evconnect "asset". Thought I have previously seen values under 2 amps near completion. These were 208 V charges or whatever the power company delivers thru evconnect.

Would love to see Toyota perfect 32 Amp J1772 delivery and double the capacity of the battery pack.

 

It's common for a sophisticated charger to balance the individual cells of a battery after bulk charging is complete. You'll see the demand drop considerably, because the output charge is being directed to specific cells in the battery pack to bring them up to the baseline. This adds to charging time and is generally worth doing for optimum discharge endurance, but it isn't going to be a problem if you need to skip the balance phase to unplug and go.

 

Batteries heat up as they charge; the faster the charge, the more heat. Then being hot when the battery is fully charged is worse than when not. So the charging algorithms dump as much energy as safely possible at the start, and then taper off to control heat near the end.

Partial charges won't harm the battery. In fact, completely charging a Li-ion battery fully often will. Don't worry plug ins don't allow a fully charge; there is a buffer of unused capacity. Except maybe Tesla, they provide the option with a warning.

 

If you lived that close in, your electric transportation upgrade should've been a charlie card.

Leave the EVs for the deeper suburbs where the cost to enable home overnight charging is one less unused outlet in the garage.

 

For these batteries, partial charges should actually lengthen battery life, compared to full charge cycles.

Normal battery charging profiles virtually always taper off as the battery approaches full.

 

To be honest it would cost very little to put in plain HD 110vac outlets in street posts or parking spots , in one town where I did a craft show, they had them in the sidewalk with an odd flush metal cover that could be opened up.
Cost could be covered by the common street meters that are already there or as a simple courtesy to retail spaces.
In our area baseline electricity is 1.5 - 3.5 cents a kwhr (hydro vrs CNG) so in many areas the cost per stall would be under $1.20 a day on an industrial wholesale cost.

If half the parking spots had an outlet the cost both for electricity and the fixtures would be very low compared to even a small number of EVSEs and city dwellers could get up to 100ish miles a day of charging if spots exist at home and at work.
I did the math on a Chevy Bolt and even though I drive a couple hundred miles every weekend, I would not need anything other than L1 charging because of my driving habits.

One of my landlords found it cheaper to provide heat and light than deal with the unpaid utility bills that fell on them during eviction because they could get a single commercial hookup for $65 a month instead of the $48 a month per unit charges and the electricity rates dropped in half under the industrial meter. Sometimes we fail to see how cheap electricity is under a single payer scenario and I think many HOAs have their head in their arse on spending more $$$ trying to charge fairly rather than trying to minimize costs to the people there.

 

I'm going to bet that it was in a northern town providing power for engine block heaters. The vast majority of North America does not have similar service built in. Even in those towns that do, a very major capacity upgrade would be needed, because BEVs pull far more power than engine block heaters.

Street lights are very commonly run at higher voltage, not 120 or 240V, at least in commercial areas. Parking meters and other streets posts typically don't have electric service at all.

 

Engine block heater plugs tended to be 120 V, 20A. Plenty for a BEV while at work. You may or may not get a full charge, but you will add miles and allow for a warm toasty car (or cooled one in the summer) when you get there.

 

Engine block heaters themselves tend to be closer to 3.3A, so you can run four or five of them on a single circuit. But BEVs are limited to just one per circuit, a second one will pop the breaker. So a major wiring and circuit upgrade is required to serve all those plugs.

And how many towns have these public engine block heater plugs anyway? Certainly no place anywhere near here.

 

Because lithium batteries are best charged by constant current until they reach a certain voltage (depending on the specific chemistry), and then constant voltage is applied and the current drops off as the cell is topped off.

Charging Lithium-Ion Batteries – Battery University

 

My 82 Diesel Suburban block heater would occasionally burn up extension cords, not sure how many amps but probably more than 3


Street lights run on a leg of 480 at 277 volts, native support for this in the standard EVSE and charger would simplify wiring for many companies

 

Engine block heaters are commonly 400 watts, which translate to 3.3 amps, easily with the capacity of common extension cords. If your unit was burning up the cords, that strongly suggests that it failed short and was drawing excessive power, and should have been replaced.

If it was burning only at a plug or socket, that suggests that the mating socket or plug was overheating from a poor contact.

 

My plug/socket would occasionally burn up

Looking at the fence full of extension cords here at work which are for block heaters I see about half are singed at the socket
Must be a common problem

 

I don't live in such a weather zone, so don't have first hand experience with it. But if the parts are exposed to weather, corrosion at the contacts will be a problem and cause more heat. The car cord end, exposed to slush and road salt, will corrode even faster.

 

Probably also some arcing from plugging it in. Most other things used on extension cords have their own switch, but block heaters don't, so it arcs a little every time you plug it in. Over time as the contact resistance goes up from corrosion or arcing, the plug could burn up. That is why the Prime charger has a temperature sensor in the end of the plug (not that it should ever see any corrosion or arcing).

Some diesels have 800-1000W block heaters, but that still shouldn't burn up an extension cord that's in good condition.

I charge my Prime everyday on a short 14 gauge 15A extension cord (despite the instructions specifically saying not to). It's fine and the cord barely gets warm. Good extension cords (with 14 or 12 gauge wire) are expensive, so a lot of people are probably using 16 gauge for block heaters (or maybe even EV charging) without knowing it's not the best idea.