Home Battery Calculator

Shoshana Ellis
3 min readFeb 22, 2021


How might ATP help homeowners understand their battery backup needs

Project duration: 3 months
My contributions: User research, sketching, prototypes
Tools: userinterviews.com, usertesting.com, Figma, Hotjar
Worked with: CTO, Product Manager, Growth Analyst and Developer

User Problem

Understanding my home battery size/ cost for my needs is confusing.
The Information I need to personalize my home battery solution for my needs is subjective and difficult to find.

Business goal

ATP was contracted by a large home-battery OEM to provide them with qualified leads to pass on to their partnered installers.


A single page battery calculator that estimates a homeowners size, cost and savings if they were to purchase and install a whole-home battery.


  • Increased engagement and time spent on the calculator page
  • Increased battery lead conversions from 0% to 3%


To help us understand our battery persona, we interviewed users we recruited through userinterviews.com.

Target users

Based on our interviews, the motivations to purchase backup power for a battery and generator persona are similar:

  • Experience: They had experienced, or knew people in their area that had experienced outages of minimum one day
  • Environment: They live with kids or family members that require them to keep the lights on, or they work from home and need to stay connected.
  • Work & medical devices: They, or a family member relies on medical equipment that requires power

Unexpectedly, environmental impact was not a main motivator in a battery persona’s purchasing decisions.

User testing

We tested a battery version of our existing generator flow with users. 4/5 of battery users felt more informed about the size and price of batteries after having completed the funnel and said the experience felt very familiar.

V1 battery flow experience

Two weeks after launch, we still had a 0% conversion rate.


It was clear we needed a new approach. When reviewing persona interviews, we identified two major differences between battery and generator personas:

  1. Return on investment (ROI): Battery personas are looking to maximize savings and longterm returns
  2. Experts: Battery personas are more brand aware, and have a more advanced understanding of a home battery solution.

In a 10 step funnel, more than 80% of leads dropped off at the intro page, and 80% of remaining leads bailed after the third step.

“I just want to know the price” — Users via intercom

We needed to reduce the number of steps and show value faster.


To increase engagement, users need to quickly discover the power and cost benefits of purchasing a home battery system.



We looked to companies like Tesla and Solar Calculator that provide estimates users can actively engage with by changing input values.

We looked at very technical product dashboards that display a lot of variable information.

Initial concept of one page battery flow

Layout & interactions

A single page layout allows users to experience an interaction between the battery estimate and inputs, making the results more discoverable and therefore more valuable.

We know battery users care most about the cost and ROI of a backup power solution. To keep them engaged, we kept an iteration of the estimate in view throughout the experience.

View our battery calculator at www.alltimepower.com