Backup power. Bills cut twice.

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.

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.

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 See the dedicated incentive pages for current figures — we do not quote rates that change quarterly on the hub page.

Commercial battery installs still qualify for up to 40% federal ITC. Residential ITC no longer applies in New England — but state rebates (CT ESS minimum $5,000, MA Connected Solutions) plus bill savings make residential batteries pencil without it. We file the paperwork either way.

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.

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.

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.

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.

Yes. Cash, secured loan, and PPA options are available for battery-only and solar-plus-battery installs. CT ESS (minimum $5,000, up to 100% by location), MA Connected Solutions performance payments, and bill savings together often bring effective residential costs well below sticker on a typical $15 – 20k battery install. Commercial installs also stack up to 40% federal ITC.

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.