Should You Charge Your Battery from the Grid?

A home battery is built to protect you from peak rates and outages—and to give you power on your terms. But what happens when the battery runs low? Before you reach for the grid, here’s what you should know.

What Is Grid Charging?
Grid charging means buying electricity from your utility to fill your battery, instead of using solar energy to do it. That electricity is not free. Every kilowatt-hour you pull from the grid is billed according to your rate schedule.

Batteries also lose a little energy each time they charge and discharge, so you always buy more than you get back. Another fact worth knowing: when the grid is down, it can’t charge your battery at all. During an outage, only solar can refill it.

Is Grid Charging Right for Me?
Here are the common pros and cons, depending on your setup.

Your Setup	Pros of Grid Charging	Cons of Grid Charging
Battery Only, No Solar	Grid charging is your only option for powering your battery. Stored energy can be set to use during peak rates or be ready for outages.	Every refill increases your monthly utility bill. There is no ability to recharge the battery during a multiple-day outage.
Solar and Battery	None. You could pay for grid energy to charge your battery… but your solar panels do that for free, automatically.	Grid charging can violate your PG&E NEM agreement.* It increases your monthly utility bill. You’ll lose energy (and cash) during each charge and discharge.

The Bottom Line
If you have solar, let the sun do the charging. Paying the utility to fill your battery adds usage to your bill, loses some energy along the way, and can be a violation of your signed NEM agreement with the utility company.

If you don’t have solar, the only way to charge your battery is through grid charging, so in that instance, grid charging is necessary. But it isn’t the best long-term answer. Adding solar lets the sun do the charging, so your battery refills for free—even during an outage.