Quick Comparison
Key published specifications for each system's flagship battery unit.
| Spec | Tesla Powerwall 3 | Enphase IQ Battery 5P | Franklin aPower 2 |
|---|---|---|---|
| Usable capacity | 13.5 kWh | 5.0 kWh (stackable) | 15 kWh |
| Battery chemistry | Lithium iron phosphate (LFP) | Lithium iron phosphate (LFP) | Lithium iron phosphate (LFP) |
| Architecture | Integrated inverter | Modular, microinverter-based | Integrated inverter |
| Scalable | Yes, multiple units | Yes, add batteries individually | Yes, multiple units |
| Backup capable | Yes (whole/partial home) | Yes (with System Controller) | Yes (with Smart Circuits) |
| Warranty | 10 years | 15 years / limited cycles | 12 years |
Capacities shown are usable energy per unit. Real backup depends on your home's loads, how many units you install, and how much solar recharges the battery each day.
The Three Systems
Strengths and trade-offs at a glance.
Powerwall 3
- 13.5 kWh usable per unit
- Built-in solar inverter reduces added hardware
- High continuous power output for large loads
- Managed through the Tesla app
Best fit: homeowners wanting an all-in-one system and strong power for appliances like AC and well pumps.
IQ Battery 5P
- 5 kWh modules — buy exactly what you need
- Microinverter design with no single point of failure
- Long 15-year warranty
- Pairs naturally with Enphase solar systems
Best fit: those who value modular sizing, redundancy, and an existing Enphase solar setup.
aPower 2
- 15 kWh usable — largest per-unit capacity here
- Works with new or existing solar arrays
- Smart Circuits for prioritizing backup loads
- Whole-home backup potential when stacked
Best fit: larger homes or anyone wanting maximum stored energy per cabinet.
Understanding Costs
What actually drives your final price.
Installed price varies widely
A single battery installed typically lands in the mid-four-figures to low-five-figures range once you include the battery, backup gateway or controller, electrical work, permits, and labor. Multi-unit whole-home backup costs more. Always compare full installed quotes — not sticker prices — from certified installers.
Federal incentive
The federal Residential Clean Energy Credit has covered 30% of eligible battery storage costs, including standalone batteries, for qualifying home installations. Tax credits depend on your situation and current law, so confirm eligibility with a tax professional before assuming savings.
Storage economics improve most when paired with solar and time-of-use rate structures. The value of a battery is different for backup security versus bill savings — be clear on your primary goal.
How Long Will It Actually Back Up My Home?
Runtime is about matching stored energy to your loads.
Backup runtime = usable battery capacity ÷ your power draw, plus whatever solar recharges during daylight. A rough way to think about it:
- Essentials only (fridge, lights, internet, phone charging, a few outlets): a single 13–15 kWh battery can often last a day or more.
- Adding heavy loads (central AC, electric heat, EV charging, well pump): runtime drops sharply — potentially to just hours.
- With solar recharge: on sunny Utah days, panels can refill the battery, effectively extending backup across a multi-day outage as long as sunshine continues.
This is why installers help you separate "backup circuits" (things you truly need) from the rest of the panel. Choosing fewer backed-up loads stretches every kilowatt-hour further.
What Utah Homeowners Should Know
Local factors that change the math.
Net billing, not old net metering
Rocky Mountain Power's current export program credits exported solar at a lower rate than the retail price you pay. That makes storing your own solar for evening use — rather than exporting it cheaply — more financially attractive for many households.
Climate & temperature
Utah's hot summers and cold winters affect batteries. LFP chemistry (used by all three systems here) handles heat and cold relatively well, but placement matters. Garages and shaded, ventilated locations are common; confirm the temperature ratings for your install spot.
Permitting & interconnection
Battery and solar installs require permits and utility interconnection approval. A licensed local installer handles this, but timelines vary by city and by Rocky Mountain Power's queue. Ask for expected timelines up front.
Outage reality
Utah's grid is generally reliable, but wind, wildfire-related shutoffs, and winter storms do cause outages. If backup security is your main goal, size your system around the specific loads you can't afford to lose.
Frequently Asked Questions
Straight answers to common questions.
Do I need solar to add a battery?
No. All three systems can be installed to back up your home from the grid alone. However, without solar you can't recharge during an extended outage, and you lose the bill-savings benefit of storing your own generated power. Solar plus storage is the most common pairing.
Which battery has the longest warranty?
Among these, Enphase advertises the longest coverage period at 15 years (subject to cycle and throughput limits). Franklin lists 12 years and Tesla lists 10 years. Read the warranty terms closely — capacity retention guarantees and cycle limits matter as much as the year count.
Can I power my whole house?
Whole-home backup is possible with all three when you install enough capacity and the right control hardware. But high-draw appliances like central air conditioning and electric heat require significant power and energy. Many homeowners choose partial backup to control cost and extend runtime.
How many batteries do I need?
It depends on your daily usage, which loads you want backed up, how long you want to run during an outage, and your solar size. A good installer will review your utility bills and design a system around measured usage rather than a one-size guess.
Are these prices going to change?
Yes. Equipment pricing, installation labor, and tax incentives all change over time. Treat any figure here as directional and get current, itemized quotes before making a decision.