How Much Does It Cost to Run 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.
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.
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 — adjust both in the calculator above.
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