Perhaps the biggest thing standing in the way of more substantial EV adoption is charging. Here are some of the primary concerns:
- Having a safe and secure location for home charging
- Cost of setting up a home charger
- Using proper charging practices for your car/battery type
- Understanding supercharging options when traveling
- Range anxiety and battery longevity
- Understanding things that impact range – temperature, speed, weight…
Let’s start with first question people ask when they arrive home with their brand new EV, and that’s “how am I going to charge this thing?” Most start with the least cost, most convenient option which is to plug their mobile charger into a 120v outlet (aka Level 1 charging). Unfortunately, it doesn’t take long to realize that a charging rate of 3 miles added to your range each hour doesn’t cut it when you don’t have a couple days to reach a full charge. So, you decide to invest in a Level 2 charger (240 volt, usually on a 40 or 50 amp circuit). And now your talking about a sizable investment of $1000 or more for hardware and installation.
The previous paragraph talks about charging hardware, but there’s another important consideration and that’s where to install the charger so your shiny new car can be charged securely (ideally in a locked garage where charging hardware can’t be tampered with). This, perhaps, is the most significant roadblock for many to-be EV owners. This is also the conundrum Tesla will encounter when they announce there ‘affordable’ EV (aka Model 2). The issue will be that many who purchase the affordable EV simply won’t have a safe place to charge. I don’t know that there’s a good solution, but this single factor will definitely slow adoption within this market segment.
The next thing that confuses many is how to properly charge their battery. Lithium batteries require some attention to proper charging practices if the EV owner expects to get good longevity from their battery. Typically, we charge our cell phones over night to 100%, as we do our laptops. This is not a good practice for cell phones, laptops, e-bikes, or EVs. Better is to let your batteries live most of their lives between 30 and 80% state of charge (SoC). This is where the battery is most stable and living in this zone significantly increases battery longevity. It also means the EV owner needs to think about their real daily range requirements and charge primarily to meet that need versus keeping the battery fully charged ‘just in case’.
Also, when supercharging, stopping the charger around 80% will save a bunch of time since the charge rate slows significantly above 80%. To illustrate this charge rate issue, assume your battery takes about 25 minutes to charge from 20 to 80% SoC. Continuing to charge 80 to 100% (another 20%) will likely take another 25 minutes. It’s better to stop at 80% and get back on the road (freeing up a charger for another EV driver), and just plan to stop and charge again a little sooner than you would if you had charged to 100%. That said, if your next charger is farther away than an 80% charge will support, then by all means, charge to 100%, though you shouldn’t have to do this very often.
As a side note, there is a new battery technology on the market now using the LFP (lithium iron phosphate) chemistry. Some EV manufacturers recommend charging these batteries to 100% (at least once per week). Some believe this battery should be charged to 100% every charge, and even when supercharging. Please, don’t! At superchargers, charge to 80% when appropriate like everyone else. Then when you’re home charging, let the battery ‘rest’ in the 30 to 80% range like every other lithium battery, with the understanding that you should then plan to charge the LFP battery to 100% once per week, and preferably drive soon after your 100% charge. Even LFP batteries should not ‘rest’ for long periods at 100% charge.
Another issue has to do with range anxiety and things that impact range. First, range anxiety. And in this regard, pay attention to your car’s state of charge, and not miles remaining. On many EVs, the displayed miles remaining are an EPA calculation and are not accurate. Better is to view current state of charge, and know what your charging options are within your remaining range (plus a reasonable buffer). With respect to Tesla, with which I’m most familiar, all charging options are displayed within the mapping display, and when a charging location is selected, the car will precondition its battery to optimize charging when the car arrives a the charging location.
Also be aware that outside temperature, driving speed, and additional weight in your car are all going to impact range, as will choice of tires, roof racks, wind direction and speed, elevation changes, aggressive driving, etc. Interestingly, your car should take all these factors into consideration when calculating your expected range relative to a supercharger. Tesla does a really good job in this regard, though you have some level of control over your car’s range by controlling many of these factors yourself, with the most important ones being speed and driving style.
One final comment before leaving the topic of charging, and that’s to ‘mind your ABCs’. This is about always plugging your EV in (Always Be Charging) when you’re not using it. If I am running multiple trips in a single day, I’ll not plug in between trips. But when I arrive home after the last trip, on the charger it goes. And it’ll go on the charger even if the current state of charge is greater than my usual charge limit which is set to 65% during the week. Each Saturday night I’ll charge my LFP battery to 100% (because that’s what Tesla’s LFP battery requires, “at least once per week”), but otherwise the charge limit is set to 65%. So again, plug in when you get home. Let the battery charge to your set charge limit. Then while still on home power, you’ll be avoiding power drain while being parked, and you’ll be able to precondition before your next drive, all without sacrificing SoC or incurring additional charging cycles. This is a very good thing!