Save $400/Year: How to Charge an Electric Car Cheaply With a Smart Timer

Last month, I opened my electricity bill and nearly dropped my coffee. My household had spent $87 more on power than the same month the year prior—and I knew exactly why. My electric car, which I’d been plugging in whenever I got home, was happily gobbling up juice during peak-rate hours. After a quick audit, I realized I was overpaying by roughly $33 a month, or nearly $400 a year, just because I hadn’t bothered to time my charging. The fix turned out to be a $20 smart plug and ten minutes of setup. Here’s exactly how to charge an electric car cheaply with a smart timer—and stop bleeding money.

Why Your Home Charging Setup May Be Bleeding $400/Year—and a Smart Timer Fixes That

If you own an EV and charge at home, you’ve probably felt the sting of a higher-than-expected utility bill. The culprit is almost always charging during peak demand hours, typically late afternoon to early evening, when electricity costs the most. Most utilities charge two to three times more per kilowatt-hour (kWh) during peak times compared to off-peak overnight rates. For an average EV with a 60-kWh battery, a full charge at peak rates can cost $12–$18, while the same charge at off-peak rates might run just $6–$9. Over a year of regular driving—say 12,000 miles—those extra cents add up to that $400 gap.

The solution is simple: shift your charging to the cheapest hours automatically. A smart timer—either a Wi-Fi smart plug for Level 1 (120-volt) charging or a programmable smart EVSE (electric vehicle supply equipment) for Level 2 (240-volt) charging—lets you schedule exactly when the juice flows. No more forgetting to plug in at 11 p.m. No more waking up to a half-charged battery because you fell asleep before setting the car’s internal timer. It’s the single highest-ROI upgrade I’ve made to my home energy setup.

The Simple Math: How a Smart Timer Saves $400/Year on EV Charging

Let’s put real numbers on it. I live in a region with a standard time-of-use plan: peak hours are 4 p.m. to 9 p.m. at $0.28/kWh, off-peak is $0.11/kWh. My EV’s battery holds 64 kWh, and I drive about 40 miles a day, which uses roughly 14 kWh. If I charge every day during peak, I’m paying $3.92 per charge. If I shift to off-peak, that drops to $1.54 per charge—a savings of $2.38 daily. Multiply by 365 days: $868.70 a year. Even accounting for weekends or lighter driving, $400 is a conservative estimate for many drivers.

For a more precise figure, use the U.S. Department of Energy’s EV charging cost calculator. Plug in your car’s efficiency, your annual mileage, and your local time-of-use rates. The output will likely confirm that a smart timer pays for itself in the first month. The Energy Star smart plug specifications also note that modern Wi-Fi plugs draw negligible standby power, so you’re not trading one vampire load for another.

In my own setup, I paired a $22 Kasa outdoor smart plug with a Level 1 charger that came with the car. The plug supports energy monitoring, so I can see exactly how many kWh I’ve shifted to off-peak hours. After the first month, my charging costs dropped from $112 to $41—a $71 savings in 30 days. That’s well over $400 if I stick with it.

Step-by-Step: How to Set Up a Smart Timer for Cheap EV Charging

Here’s the walkthrough that worked for me, and it should work for most Level 1 chargers. For Level 2, the steps are similar but require a smart EVSE instead of a plug.

1. Check your off-peak hours. Call your utility or log into your online account. Off-peak is often 10 p.m. to 6 a.m., but some utilities have mid-day “super off-peak” windows for solar-heavy grids. Write down the exact start and end times.
2. Buy a compatible smart plug. For Level 1, get a Wi-Fi smart plug rated for 15 amps (most Level 1 chargers draw 12 amps continuous). Make sure it’s outdoor-rated (IP65 or higher) if you’ll use it in a garage or carport. I use a Kasa KP401, but TP-Link, Amazon, and Wyze make good ones. For Level 2, you’ll need a smart EVSE with scheduling built in, like a ChargePoint Home Flex or a Grizzl-E with a smart timer add-on.
3. Set up the plug in your home automation app. Plug it in, connect to Wi-Fi, and name it “EV Charger” in the app. Most plugs work with Alexa or Google Home, so you can also control it by voice.
4. Create a schedule. In the app, set the plug to turn on at the start of off-peak hours and turn off at the end. For example, “On at 10:00 p.m., Off at 6:00 a.m.” every day. Some plugs let you add a second window for mid-day off-peak periods.
5. Test it. Plug in your EV, wait a few minutes, and confirm that the car starts charging only during the scheduled window. I made the mistake of forgetting to disable the car’s internal timer, which overrode my smart plug schedule—so double-check that the car’s timer is off or set to a wider window.

That’s it. The first morning, I woke up to a fully charged car and a lower bill. The automation means I never have to think about it again.

Which Smart Timer Works Best for Your EV? A Practical Buying Guide

Not all smart timers are created equal, and the best choice depends on your charging setup. Here’s my practical guide based on what I’ve tried and researched:

• Level 1 (120V) with a portable charger: A smart plug is your cheapest option. Look for one with energy monitoring (like the Kasa KP401 or Emporia Vue smart plug) so you can track your savings. Avoid generic mechanical timers—they’re less reliable and don’t offer app control.
• Level 2 (240V) with a hardwired charger: You need a smart EVSE. The ChargePoint Home Flex has excellent scheduling and integrates with your utility’s time-of-use rates. The Grizzl-E Smart is a rugged outdoor option with Wi-Fi control. Both let you set schedules via their apps.
• Level 2 with a plug-in charger: Some EVSEs come with a NEMA 14-50 plug. You can pair them with a heavy-duty smart contactor rated for 40 amps, but that’s a more advanced DIY job. For most people, buying a smart EVSE outright is simpler and safer.
• Home assistant integration: If you use Home Assistant, you can create even smarter automations—like charging only when solar production exceeds a threshold or when electricity prices drop below a certain point. I’ve set mine to pause charging if the plug detects a sudden voltage drop, which indicates grid stress.

One counterintuitive insight: don’t assume the most expensive smart timer is the best. I tried a $50 “smart” EVSE that had a clunky app and no energy monitoring. My $22 smart plug outperformed it in every way for Level 1 charging. Match the gadget to your actual use case, not the marketing hype.

Common Pitfalls to Avoid When Using a Smart Timer for EV Charging

I hit a few snags during my first week. Here’s what to watch for:

• Your car’s internal timer may override the smart plug. Many EVs have a “departure time” or “charge schedule” feature. If you set both the car and the plug, they can conflict. Solution: turn off the car’s timer and let the plug control everything. I keep my car’s schedule set to “immediate charge” and let the plug decide when power flows.
• Time-of-use rates can change seasonally. Some utilities shift off-peak hours between summer and winter. Set a calendar reminder to check your utility’s rate updates every six months, then adjust your smart plug schedule accordingly. I missed this and paid peak rates for two weeks in June.
• Using a non-weatherproof smart plug outdoors. Ordinary indoor plugs can fail in rain or snow. Always check the IP rating. For garages, an indoor plug is fine, but for carports or driveways, choose an outdoor-rated model with a gasket-sealed cover.
• Forgetting to test after power outages. A power surge can reset a smart plug to “off” or lose its schedule. I added a routine in my smart home app to alert me if the plug hasn’t turned on within 30 minutes of the scheduled start time.

One more tip: if you live in a region with time-of-use rates that include a mid-day super off-peak window (common for solar-heavy grids), program your smart plug to charge during both windows. It’s worth bookmarking this setup before your next utility rate change.

Practical takeaway: A $20–$50 smart timer can save you $400 a year on EV charging—and it takes less time to set up than your morning coffee. Check your off-peak hours, buy an outdoor-rated smart plug or smart EVSE, schedule it, and let automation do the work. Your wallet (and your grid) will thank you.