Three Tier 1 batteries — FranklinWH, Tesla Powerwall 3, and Enphase IQ Battery 5P — installed across Connecticut, Massachusetts, and Rhode Island. Eligible for CT ESS, MA Connected Solutions, and the 30% federal ITC.
A battery is not just for outages. The financial case is built on four stacking benefits — and Teamsun handles the paperwork on every one of them.
Backup during outages
Keep your fridge, lights, and well pump running through a New England nor’easter. Whole-home or essentials-only configurations available.
Demand-response payments
Get paid by your utility for letting them dispatch your battery during peak demand windows. CT ESS and MA Connected Solutions both pay residential participants.
Time-of-use savings
Charge cheap (overnight or solar surplus), discharge during expensive peak hours. Real ROI on Eversource Rate-7 and similar TOU tariffs.
Federal ITC eligibility
Per the Inflation Reduction Act, standalone batteries (no solar required) qualify for the 30% federal ITC. Confirm with your CPA — we file the paperwork either way.
The three batteries we install
FranklinWH. Tesla. Enphase.
No fourth brand. We install the three batteries we trust on our own families' homes — and pick the right fit during your site visit.
Tier 1 battery
FranklinWH aPower
Whole-home AC-coupled battery — pairs with any solar system regardless of brand. Modular and stackable. Eligible for CT ESS and MA Connected Solutions enrollment.
Capacity
13.6 kWh modular
Warranty
15 yr · 80% throughput
Tier 1 battery
Tesla Powerwall 3
Integrated solar inverter and battery in one unit. Best fit for new installs where panel count matches Powerwall’s built-in 11.5 kW PV input. DC-coupled efficiency on new systems.
Capacity
13.5 kWh per unit
Warranty
10 years
Tier 1 battery
Enphase IQ Battery 5P
AC-coupled stackable battery designed for Enphase microinverter systems. Per-module monitoring, sunlight-backup capable. Best fit for IQ8 microinverter installs.
Capacity
5 kWh modular · stackable
Warranty
15 years
What's included
Every battery install, end to end.
Three Tier 1 brands
FranklinWH, Tesla Powerwall, and Enphase IQ Battery — we are certified installers on all three. We pick the brand that fits your roof, not our inventory.
New installs and retrofits
Adding a battery to a brand-new Teamsun solar install or retrofitting onto a system we did not build. Both paths fully supported.
Program enrollment
CT ESS (Connecticut), Connected Solutions (MA), and Rhode Island demand-response paperwork — all filed by Teamsun on your behalf.
Sized to your real use
Aurora pulls your last 12 months of utility data. Battery capacity is sized to your actual load profile — not a brochure number.
Our approach
Our process, refined through 9,000 installs.
01.
Design
A 15-minute call, then a remote or on-site visit. Aurora-based design, panel and battery brand named on the proposal.
02.
Build
Permits filed, utility interconnection submitted, and equipment staged at our Bristol warehouse.
03.
Install
Local crew, local trucks. Most homes finished in 2 – 3 days. Final inspection scheduled before we leave.
04.
Perform
PTO from your utility, ITC and rebate paperwork filed, and 25 years of local service after the system goes live.
Your incentive stack
Federal, state, and utility stacked.
On a typical $30K install in Connecticut, the total incentive stack lands between $13,000 and $17,000. We file every form with you.
Federal ITC
30%
Tax credit, claimed in the year of install. Locked through 2032.
CT ESS battery rebate
Up to $7,500
One-time check from CT Green Bank, paid through your installer.
Net metering
Full retail
1:1 offset on what your panels send back to Eversource or UI.
CT property tax exemption
$300 – $700/yr
System value excluded from your assessment. Sales tax also exempt.
Where we work
9,000+ rooftops across three states.
Connecticut, Massachusetts, and Rhode Island. Every pin is a Teamsun install. We're licensed in ME, NH, VT, and FL too.
“Teamsun was the only crew that walked the roof, named the panel brand, and answered every question without checking with someone. Same lead tech came back a year later when I added a battery.”
“Three of my neighbors had Teamsun, so I called them. The crew was on my street five days after I signed.”
“They knew the historic district secretary by first name. Saved us six weeks on permitting alone.”
“Same lead tech who installed it came back four years later to swap an inverter under warranty. No charge, no excuses.”
Battery FAQ
Questions homeowners ask about batteries.
Which battery brand is best?
There is no universally best battery — only the best fit for your roof, your existing solar, and your goals. FranklinWH wins on retrofit flexibility and modular capacity. Tesla Powerwall 3 wins on new-install efficiency when sizing matches. Enphase IQ Battery 5P wins on Enphase microinverter systems and per-module monitoring. We pick during your site visit.
Can I add a battery to a solar system you did not install?
Yes — see our battery retrofit service. FranklinWH and Enphase are both AC-coupled and play nicely with most existing inverters. Tesla Powerwall 3 retrofits are case-by-case because the unit replaces a string inverter. Most national installers refuse retrofit work; we built a team specifically around it.
How much can I make from CT ESS or MA Connected Solutions?
Payments are calculated by program year, battery capacity, and your willingness to participate in dispatch events. CT ESS pays an upfront passive incentive plus per-event performance payments. MA Connected Solutions pays per-summer-event performance. See the dedicated incentive pages for current figures — we do not quote rates that change quarterly on the hub page.
Does a battery qualify for the federal ITC?
Yes. Under the Inflation Reduction Act, batteries 3 kWh or larger qualify for the 30% federal investment tax credit, including standalone batteries with no solar attached. We file the ITC paperwork as part of the install.
How long does battery installation take?
Adding a battery to a new solar install adds zero or one day to the on-roof timeline. A standalone battery retrofit on an existing system takes 1 – 2 days on-site, plus 3 – 6 weeks for permitting and utility approval depending on your AHJ.
Will the battery power my whole house during an outage?
Depends on capacity and your panel layout. A single 13.6 kWh FranklinWH or Powerwall 3 typically backs up essentials (fridge, lights, internet, well pump, gas-furnace blower) for 12 – 36 hours. For whole-home backup including AC and electric heat, you usually need two units stacked.
How long does a battery last?
Manufacturer warranties run 10 – 15 years with throughput guarantees. Real-world cycle life on lithium-iron-phosphate chemistry (FranklinWH, Powerwall 3, IQ 5P) is typically 6,000 – 10,000 cycles — meaning daily use for 15+ years before significant capacity loss.
Can I retrofit a battery to a system installed in 2014?
Yes, in most cases. We pull your inverter make and model, check for AC-coupling compatibility, and design a retrofit. The most common path is a FranklinWH or Enphase 5P installed parallel to your existing AC output. We do this work weekly across CT, MA, and RI.
Do you offer financing for battery-only projects?
Yes. Cash, secured loan, and PPA options are available for battery-only and solar-plus-battery installs. The federal ITC plus state rebates often bring effective costs 40 – 60% below sticker on a typical $15 – 20k battery install.
What happens if a battery fails after install?
Manufacturer warranty covers the battery for 10 – 15 years depending on brand. Teamsun handles all warranty claim paperwork and on-site service. You call our Bristol office and a person picks up.
Free quote
Ready to go solar? Request a quote today. It's free.
A 15-minute call with a designer who knows your town. No closer on the line. No follow-up unless you ask for one. $0 down options available.
