How to Choose a Solar Battery Company in California

Three kinds of company, three kinds of promise

Start by naming who is responsible for what, because a sales pitch tends to blur it.

The manufacturer's promise is the product warranty on its spec sheet. Tesla's Powerwall 3 datasheet lists a 10-year warranty. Enphase's IQ Battery 5P data sheet lists a 15-year limited warranty or 6,000 cycles, with more than 60 percent capacity retained. FranklinWH's aPower 2 datasheet lists 15 years or 60 MWh of throughput.

The installer's promise is the workmanship: the wiring, the roof or wall penetrations, the permit, commissioning and the paperwork with your utility. Its warranty is whatever its contract says, and it is only as good as the company's ability to honor it.

If you lease the battery or buy its output, the financing company owns the equipment and its contract decides who fixes what. Ask each of them, in writing, who you call when the battery stops working in year six.

Check the license, and the class that covers batteries

The Contractors State License Board licenses California contractors, and the CPUC's consumer guide tells you to check the license, and the salesperson's Home Improvement Salesperson registration if they have one, on CSLB's website at cslb.ca.gov or by calling 800-321-CSLB (2752).

Which license class may install a battery has been disputed. CSLB defines a C-46 Solar Contractor as one who installs, modifies, maintains and repairs thermal and photovoltaic solar energy systems. In 2024 CSLB adopted a rule stating that a battery energy storage system is not part of a photovoltaic system, adding batteries to the C-10 electrical contractor's scope, and letting a C-46 contractor install a battery only as 'incidental and supplemental' to a solar installation and only up to 80 kWh. The Office of Administrative Law approved it on June 5, 2024, but CSLB says its effective date has been stayed by court order pending San Diego County Superior Court Case No. 27-2024-00029818-CU-TT-CTL.

You don't need to settle that case to protect yourself. Ask for the license number and classifications, confirm them on CSLB's site, and ask the contractor to write on the contract which classification covers the battery portion of the work.

The CPUC guide you have to sign

In PG&E, SCE and SDG&E territory, and for Bear Valley Electric, PacifiCorp and Liberty, a solar provider submitting an interconnection application for a residential customer must collect your initials and signature on the California Solar Consumer Protection Guide. The CPUC says you must be given time to read it before signing. Version 4 was published in 2025 and includes a section on combining solar with storage.

Treat the guide as a test of the company. One that hands it to you early and walks through it is behaving the way the CPUC intends. One that produces it for a signature at the end of the visit, or skips it for a 'battery-only' job, is telling you something about how the rest of the paperwork will go.

Program lists are not quality ratings

Two lists get quoted as endorsements, and neither is one.

The Self-Generation Incentive Program publishes an Approved SGIP Developer List, and the CPUC's SGIP page points applicants to it to find an installer. Being on it means the company can file SGIP applications. It says nothing about workmanship, and it only matters if you actually qualify for an open SGIP budget.

PG&E's $7,500 Permanent Battery Storage Rebate requires enrolling the battery in the Emergency Load Reduction Program through your battery provider, and PG&E names Tesla's Virtual Power Plant with PG&E, Enphase's Virtual Power Plant program and Sunrun's CalReady ELRP program as enrollment paths, with PG&E's Automated Response Technology program as the fallback. That tells you which enrollment route a given product uses. It doesn't make one installer better than another.

What a comparable battery quote shows

You can't compare two battery companies on a monthly payment. Ask every bidder for the same items.

The battery model, the number of units, and usable capacity in kWh, taken from the manufacturer's spec sheet. Continuous output in kW, which decides how many appliances run at once. Which circuits are backed up, and whether a backup gateway, switch or critical-loads panel is included. The operating mode it will be set to: backup reserve, self-consumption or time-of-use shifting. Whether the design is AC-coupled to existing solar or DC-coupled to new panels.

Then the paperwork: the permit, the utility interconnection application and Permission to Operate, a schedule for each, and the total installed price with any rebate shown as a separate, conditional line. If a quote assumes PG&E's outage rebate, it should also show how many qualifying outages your account has had.

If the company goes out of business

Installers do go out of business, so plan for it before you pay. The product warranty usually still runs to the manufacturer, but you need proof you own a registered unit.

Before final payment, get the serial numbers, the commissioning report, the warranty registration confirmation from the manufacturer, and your own login to the monitoring app. Ask whether the manufacturer will send its own service network or require a certified installer, and how you find one. Keep the permit final and the utility's Permission to Operate letter with those documents. A replacement contractor can pick up a system that has all of them. One that has none may start from scratch.

Free-battery offers: match them to a real program

Some Californians can get a battery at no charge, which is why 'free battery' pitches work. PG&E's Residential Storage Initiative installs a permanent battery at no charge for customers on EPSS circuits with five or more EPSS outages since January 1, 2024 who are enrolled in CARE, FERA, Medical Baseline or the Self-Identified Vulnerable program. PG&E says it contacts eligible customers by letter or email, and that its program partner, Resource Innovations, handles outreach.

If an offer doesn't trace back to a program like that, it is probably a lease, a subscription or a loan with the cost moved somewhere you can't see yet. Ask which program pays for it, then look that program up on the utility's own website.