The e-rickshaw battery box

A product design question from a product manager interview, set at Tripahiya Energy, a fictional ev hardware company.

The question

Skills this case tests

A starting structure

Goal and unit-cost limit first → map the chain (dealer, fleet owner, driver) → pick one user → journey of a pack from charge to failure → ideas within the cost limit → v1 → metrics

How to approach this case

Begin with what Tripahiya needs: more units sold, lower warranty costs, or a stronger brand with dealers. Ask about price limits early, because this market buys on cost and every added part shows up on the bill. Then map everyone who touches the battery, from the dealer who sells it to the person who charges it at night and the person who drives it all day. They may not be the same people, and they may not trust each other. Pick one to design for and say how the others still benefit. Walk through one day and one full life of a pack, looking for where money is lost. Remember heat, unstable power, rough roads and limited literacy. A strong close names a v1 that fits the cost limit, a north star tied to pack life, and a guardrail on price and claims.

The full method for product design (product sense) questions · A worked example answer

After the mock interview you get scores on five skills, what to fix with quotes from your answers, and the ideal path for this case.