A second opinion on your battery, in writing

1. 1

   Quote check

   Send me an installer's quote. I work out the price per kWh, list what is missing from it, and mark anything that should be questioned before you sign.

2. 2

   Rate check

   Twelve months of your bills, priced on your current plan and on the time-of-use plan a battery is built for. For Dominion that is Rate 7. You see what each month would have cost and which plan wins over the year.

   Dominion SC · Berkeley Electric

3. 3

   Backup plan

   What stays on in an outage, and for how long, at two battery sizes. Built around your big loads: heating and cooling, water heater, EV, well or pool pump.

4. 4

   Recommended system

   A good option and a better one, each with a price range and a way to add capacity later.

5. 5

   Solar option

   If you want panels: how many your system can take and your space fits, which way to face them, and a cost range for panels and mounting. In the Charleston area, also the expected yearly output and its effect on your payback. Covers solar wired into the battery, on an unshaded spot.

6. 6

   Payback

   Years to break even on your numbers, under 2026 rules. The federal credit for a cash or loan purchase ended December 31, 2025, and the math reflects that. South Carolina's 25% solar credit is counted where solar is part of the plan.

   Dominion SC · Berkeley Electric

7. 7

   Next steps

   A parts list with links if you are buying it yourself. In the Charleston area, also the installer who put in my own system.

I'm Vinh. I've done what you're about to do, on my own house, and the results are public.

I run this system24.6 kWh across two EcoFlow inverters, a Smart Home Panel 3 as my main panel, and 6.38 kW of solar I built myself.See my setup →My bills are publicSeven months of Dominion bills, posted with the account details removed. $311 on the old rate, about $190 on the new one, for the same usage.See the bills →I've been through the inspectionMine was one of the first Smart Home Panel 3 installs North Charleston's inspectors had seen. It did not pass on the first visit, and passed two days later.Read what happened →See the work before you payA full sample plan, written from my own bills and receipts.Read the sample (PDF) →

My background

I started in electronics and telecommunications. I spent eight years in the Marine Corps, two of them in school for electronic theory, radio, telecom, computers and fiber optics. As a Sergeant I graduated at the top of my class from the Electronics Maintenance Technician course, the Marine Corps' advanced course in electronic theory and system repair for maintenance supervisors. I left as a Staff Sergeant supervising 120 people in radio and electronics maintenance.

After that I worked on communications systems for military vehicles. For more than a decade since, I've engineered computing and network systems for the Department of Defense: designing them, installing them aboard ships and validating that they work. Today I'm a senior systems engineer. I bring the same habits to your plan: size it to the need, check the numbers, and write it down. I hold a bachelor's degree in network engineering and security.

1. 1Pay $149. Checkout takes you straight to a short form.
2. 2Answer the questions and upload your bills. It takes about 15 minutes.
3. 3Your plan arrives by email as a PDF within 5 business days.
4. 4Questions afterward? Reply to that email. I answer them myself.

• 12 months of bills, or a usage download from your utility
• Your current rate plan
• A photo of your main panel and its label, so I know your service size
• Your big loads: heating and cooling type, water heater, EV, well or pool pump
• What you want covered: a few hours, or a multi-day hurricane outage
• Any generator or solar you already have
• If you want solar: where the panels would go, and which way that spot faces
• Your budget, and whether you plan to install it yourself
• An installer quote, if you have one

The rate check and payback need a utility I have modeled: today that is Dominion Energy South Carolina and Berkeley Electric. On any other utility the plan is the quote check, backup plan, recommended system, solar option and next steps, at the same $149.