Is a battery tender expensive to run?

Leaving one on the motorcycle all winter costs a dollar or two — far cheaper than a dead battery in spring. At typical use it adds about $1.20 to a monthly electric bill at the US-average rate, but that swings from $0.84 in the cheapest states to $3.13 in the most expensive.

How many watts does a battery tender use?

Battery Tender typically draws about 30 running watts. It's a resistive load, so its startup and running wattage are the same. Check the nameplate or label on your specific unit for its exact rating.

How much electricity (kWh) does a battery tender use?

At typical use (30 W for 8 hours a day), a battery tender uses about 0.2 kWh per day — roughly 7 kWh per month, or about 1% of what the average US home uses in a month (863 kWh). Energy used doesn't depend on your electricity rate — only the bill does.

How can I lower the cost of running a battery tender?

Leaving one on the motorcycle all winter costs a dollar or two — far cheaper than a dead battery in spring. You can also cut the cost by lowering your electricity rate — many utilities offer cheaper off-peak hours — or simply by running it fewer hours. The calculator on this page shows how changing hours per day or your electricity rate moves the number.

How Much Does It Cost to Run a Battery Tender?

A maintenance charger floats at a few dozen watts at most, and near zero once the battery is full. At the US-average rate of 16.5¢/kWh, running a battery tender costs about $1.20/month ($14.44/year) at typical use. Adjust the watts, hours, and your rate below for your exact number.

Power (watts)

Hours per day: 8

Days per week: 7

Your state (sets the rate)

Electricity rate ($/kWh)

Cost to run a battery tender

$14/yr

Per day: $0.04
Per month: $1.20
Energy per year: 88 kWh

Cost = power (kW) × hours × days × your rate. Defaults are typical values — enter your appliance's actual watts (often on a label) and your real rate for a precise figure.

How much electricity does a battery tender use?

At 30 W for 8 hours a day, a battery tender uses about 0.2 kWh per day — roughly 7 kWh per month and 88 kWh per year. That's about 1% of the 863 kWh the average US home uses in a month. Energy use is the same everywhere — only the price per kWh changes your bill.

Wondering about the circuit instead? See how many amps a battery tender draws.

Cost to run a battery tender by electricity rate

Same 30 W appliance, 8 h/day — the bill changes with where you live.

Scenario	Rate	Per month	Per year
Cheapest states (North Dakota)	11.5¢	$0.84	$10.08
US average	16.5¢	$1.20	$14.44
Most expensive (Hawaii)	42.9¢	$3.13	$37.55

Find your state's rate on the electricity rates by state page, or see the appliance wattage chart for more devices.

Frequently asked questions

At the US-average residential rate of 16.5¢/kWh, a battery tender drawing 30 watts for about 8 hours a day costs roughly $0.04 per day, $1.20 per month, and $14.44 per year. Your actual cost depends on your electricity rate and how much you use it, and the calculator on this page adjusts for both.

Ask AI about this

Open an AI assistant with a question grounded in this page.

ChatGPT Claude Perplexity Google AI Grok

Electricity cost calculator Estimate your whole bill All appliances

How Much Does It Cost to Run a Battery Tender?

How much electricity does a battery tender use?

Cost to run a battery tender by electricity rate

Frequently asked questions