Could a 120v portable charger be boosting my electricity bill in colder weather?

[MasonM]

I’ve been using a 120-volt portable charger for my EV since I bought it, but I’m starting to wonder if that’s why my home electric bill spiked last month. It feels like it’s taking more energy to finish a charge, especially now that the weather is colder.

[Patrick90]

I hear you. A 120V plug-in unit is a slow trickle, and cold weather can change how the battery accepts power, so charging can take longer. I noticed my bill creep up during winter and it took me a while to separate EV charging from space heaters and hot water. Comparing meter readings helped me see if the charging sessions aligned with the spikes.

[Gregory43]

I kept a simple log for a month. Each night I noted start and end times and the kilowatt hours shown on the main panel after each session. I was seeing roughly an extra 6-8 kWh per night during the cold snap, which added up fast. It wasn’t just the EV stuff either—the whole house stayed warmer and that didn’t help the math.

[FrankLL]

Do you think the unit is the real issue, or could the rate and other winter loads be the bigger factor?

[James.T]

One small thing I did was try a plug-in wattmeter on the device to see its actual draw. It hovered around 1.2 to 1.5 kW at 120V, and it ran longer as the battery sat in the cold. I didn’t flip to a higher voltage setup because of cost, but it did seem more efficient when I could do a faster, higher-voltage session.