Franklin Home Power Battery Review: Not the Cheapest, but It Gets the Job Done

6.8

Franklin Home Power

Like

• High peak power output
• 12-year warranty
• Can be installed without solar panels

Don't like

• Expensive
• Lacking modularity

The Tesla Powerwall is one of the most popular home battery backups available on the market. And on the surface level, the Franklin Home Power battery could be mistaken as a Powerwall clone, sharing similar specs and functionality. But look a little deeper and you'll realize that both batteries have too many differences to be considered identical twins. 

FranklinWH, the company behind the battery, hasn't been around that long but is already making a big splash in the battery and renewables space. The company was founded in 2019 and the Franklin Home Power battery was released to market in 2022. For such a new battery, the availability is already very wide. FranklinWH claims its battery system is available in every state.  

The Franklin Home Power system has predominantly been all about backup power, powering your home in the event of a grid outage. But recently, FranklinWH has put some focus into time of use rate offsetting as well, helping you save money during times of the day when electricity rates are at their highest. 

"The Franklin system is all about whole-home backup," Josh Brooks, a member of the service engineering team at FranklinWH, told CNET. "We do have the ability to do things like energy arbitrage, so things like time of use offset. But our main focus is backup. Our main focus is making sure that you still have power, even in an outage."

We did not conduct any hands-on testing for this review. Batteries are part of a complex home energy system that varies from house to house. Instead, this review is based on publicly available information online from FranklinWH and an interview with Brooks, conducted in September at RE+ 2023, a renewable energy trade show. 

Here's what you should know about Franklin Home Power. 

What do I get with a Franklin Home Power Battery?

With Franklin Home Power, you'll get a large 13.6 kWh worth of energy storage capacity, solid performance specs and a 12-year warranty. The FHP's peak power output is an impressive 10 kW, but its continuous 5 kW output falls a bit short in comparison to other batteries on the market. We'll talk more about specs and warranty details below.

Since this is an AC-coupled system, it's compatible with new and existing solar panel systems. If you don't plan on getting solar, you can also use the Franklin Home Power battery as a standalone backup power source. However, this system is optimized to work with solar, according to Brooks. 

Here's a quick glance at some of the specs for the Franklin Home Power battery.

System components

With Franklin Home Power, you'll have two boxes on your wall: the aPower and the aGate. The aPower is the larger box that contains the actual battery, as well as the AC-coupled inverter. The battery stores your energy and the inverter converts the DC electricity generated from your solar panels into usable AC electricity for your home.

"The aPower is kind of the powerhouse behind everything. That's the actual battery system," Brooks said. "It's a battery and an inverter in a single enclosure."

The other box is the aGate, a centralized place to connect everything. Your grid connection, solar connection and energy management components live inside the aGate. The aGate also contains the automatic transfer switch, which switches your system to backup mode when it detects a grid outage.  

"It's a gateway for energy management. Everything can be run through this box without having to add extra hardware," Brooks said. "We can tie in pretty much all of your different energy sources with the aGate."

Capacity and modularity 

The Franklin Home Power's capacity is pretty big. One battery (aPower) unit can store 13.6 kWh of energy. If you're looking for a battery with larger storage capacity, this is worth considering. But it's not a modular battery, meaning if you end up needing more than 13.6 kWh at some point, you'll have to buy another aPower unit -- this can get very expensive.

Our scoring methodology rewards batteries that are more modular, because you're better able to size your system to your needs and to upgrade more easily and affordably if your needs increase. But if your energy needs mean a 13.6kWh battery (or a multiple of it) is right for you, modularity doesn't really matter.

You can install up to 15 aPower battery units for a total energy storage capacity of 204 kWh. And while this is certainly impressive, a single residential home will most likely never need anywhere close to this much storage capacity. 

Performance and efficiency

The Franklin Home Power's performance and efficiency specs aren't too shabby. Its round-trip efficiency is 89%, meaning 11% of your electricity gets lost on the way into storage. But this is normal -- the industry average is about 90%, so it's not too bad.

The FHP also has a 100% depth of discharge rating, meaning you'll be able to use all of your battery's capacity and drain it down to zero without risking harm to the battery. But just because you can drain your entire battery all in one go, doesn't mean you should. For the sake of preserving your battery's capacity retention and overall lifespan, try not to drain your battery completely. 

Where the Franklin Home Power really shines is its peak power output. This is a measure of how much energy your battery is able to put out all at once without shutting down. Peak power is used for starting up large loads, like your AC, heat or fridge. Batteries also have a continuous power rating as well, which is a measure of how much power it can output continuously. 

One Franklin Home Power battery unit has a peak power output of 10 kW and a continuous power rating of 5 kW. The FHP battery's peak output is very powerful, meaning it can start up large appliances like your AC after a blackout. But its continuous rating is quite a bit weaker than other residential batteries we've seen on the market lately that are capable of outputting 7 kW to 9 kW continuously. And while FHP's peak output is powerful, batteries are only meant to "peak" for a very short amount of time, usually only lasting a few seconds or minutes depending on the battery.

Warranty

With such a large purchase, you're going to want a good warranty. The FHP's warranty is solid. The FHP is covered for 12 years. Most batteries are only warranted for 10 years. The expected energy lifespan of the battery is fairly average. The guaranteed 70% capacity retention by the end of your warranty is the industry average, and that's fine.

Years covered: This is the length of time your battery system is covered under warranty. After 12 years, your warranty expires.

Energy throughput: This is the manufacturer's expected total amount of energy (in megawatt-hours) the battery will provide during its lifespan. Once your battery hits its rated throughput, in this case 43 MWh, your warranty expires, even if you still haven't hit the 12 year mark. 

End-of-warranty capacity guarantee: Battery capacity retention shrinks over time. An end-of-warranty capacity guarantee is the manufacturer's promise that your battery will retain up to a certain percentage of its original capacity by the time your warranty expires. In this case, FranklinWH guarantees that your battery will be able to retain at least 70% of its original capacity by the end of your warranty period.

Customer support

Your installer should be the first person you contact if something's not working properly. They're most familiar with your specific system and can visit the battery on-site to diagnose the issue. But if you can't get into contact with your installer for some reason, then it's nice to know you can contact FranklinWH for assistance.

There are two ways you can get in contact with FranklinWH for support-related issues. You can call the support number or fill out an online form to leave a ticket and wait for someone to contact you. There's also an extensive FAQ page and documents to help you out if you think it's something you're able to handle on your own.  

FranklinWH app

Like most home batteries, the Franklin Home Power system comes with an app. The app was designed to be easy to use and understand what's happening with your energy. "The biggest thing is just to make it simple," Brooks said. "The idea is, 'here's the energy flow, here's where your power is going.' Make it simple." 

As far as main features go, the FranklinWH app lets you monitor your solar energy production and your home's energy consumption, view historical energy data about your home and choose your battery's operating mode. You'll be able to pick between three different modes to set. 

Backup standby mode is ideal if you want your battery fully charged and you only plan to use it during an outage. If you only want to reserve a certain amount of your battery's capacity for backup and use the rest to power your home throughout the day, then self-consumption mode is the better option. But if your top priority is saving money and offsetting expensive time of use rates, choose load shifting.  

How much does the Franklin Home Power system cost?

Price is not one of the Franklin Home Power's strong categories. After taxes and installation labor, the average cost of the Franklin Home Power system is about $18,000. This is fairly expensive for a 13.6 kWh battery. Even after taxes and labor costs, you can find other batteries of similar size for under $15,000. For instance, the Tesla Powerwall, a 13.5 kWh battery, costs between $9,000 and $13,000. 

But no matter how much a battery costs, we recommend exploring multiple battery options. A lot of installers are certified to install multiple battery brands. Taking the time to get multiple quotes from different installers in your area could save you thousands too.

Is the Franklin Home Power battery my best choice?

Home batteries aren't one-size-fits-all. No two houses and household energy needs are the same, so the best battery for your neighbor might look different from the best battery for you. The Franklin Home Power battery is compatible with new and existing solar systems. Its also got solid performance and efficiency specs and a good warranty. But it's also more expensive than other similar batteries available, and it's less powerful. 

Just remember that the best battery for you is one that meets your household's energy needs and budget. If the Franklin Home Power meets your standards, that's great. But it's important to know that there are tons of home batteries on the market to choose from, so don't limit yourself to just one battery. Take your time and explore multiple battery options from installers in your area, and try to get multiple quotes to see if you can find a lower offer.

How we evaluated the best solar batteries

First let's be clear: Not every solar battery is right for every home. Solar is a very site-specific and personalized decision process, so it's a little tricky to pinpoint exactly which solar battery is the "best" battery for your home's energy needs without doing an on-site consultation. 

It should also be said that we didn't have any form of hands-on testing with any of the batteries we scored. This methodology also assumes you're purchasing a battery for the main purpose of using it for energy backup. If you mainly plan to use your battery for energy offset or to take part in a virtual power plant, there are likely better options than what we have featured in our reviews and rankings. We strongly encourage you to do your own research, as well as to speak with installers in your area. An installer will be able to get a better understanding of your home's energy use and what sort of system you might need. 

We used a few ways to evaluate and compare these batteries to find the stand-outs. Here's how we developed our list of top solar batteries.

First, we determined which categories would be used to evaluate each battery's performance, capacity and value. We also weighted each category. The weight of each category reflects the importance we felt was relevant to the average consumer: 

• Modularity: 20%
• Warranty: 20%
  
• Round-trip efficiency: 15%
  
• Power output: 15%
  
• Depth of discharge: 10%
  
• Price: 5%
  
• Price transparency: 5% 
  
• Customer support options: 10%
  

We looked at more than 15 of the most widely available batteries on the market and collected the data for each category to compare the numbers. Each category (for every battery) was given a rating (from 1 to 5) to evaluate which aspects of each battery were above average (among our list), just average or below average.

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