Once you’ve looked at the outside (form, surface, interface) and the skeleton (mechanisms, structure), the next step is the internals that bring a product to life.
For most (like me), without formal training, this is where things get intimidating. Batteries, motors, and PCBs look complex, but if you break them down the same way you did form and structure, logic of placement, layout, cost, reliability start becoming clearer.
1. Batteries and power
Batteries define how long something runs, how heavy it feels, and how stable it sits. Placement is a deliberate design choice and the right constraint as well.
Laptops keep batteries flat and low so the machine stays stable on a desk.
Electric scooters hide batteries in the deck for balance and safety.
Xiaomi smart cameras use small lithium-ion packs for compactness, optimising for size and not life.
2. Motors
Hair dryers put motors in the handle for straight airflow.
Robot vacuums put motors near wheels and suction paths to avoid energy wastage.
Native RO purifiers place pumps on mounting plates with dampeners to reduce vibration and protect electronics.
3. PCBs
Routers mount PCBs close to vents to avoid overheating.
Smart locks place boards away from metal housings towards the facia to prevent interference.
Game controllers split PCBs to align with button clusters distributed across the body.
4. Wiring and connectors
iPhones use press-fit connectors that save space but break if reused.
IKEA lamps often use soldered wires. They're cheaper but hard to repair.
Premium headphones use detachable cables for longevity.
5. Layout logic
Scooters have batteries in deck, motor in wheel, and PCB in stem.
Smart speakers have vertically placed PCBs for antenna performance.
High-end cameras have stacked PCBs to save space but increase heat challenges.
6. Failures
Batteries swell when thermal design is poor.
Motors burn out when ventilation is inadequate.
Connectors fail if glued or loosely fit instead of snapped.
PCBs warp or delaminate without support structures.
Things to do
Pick one product with electronics inside (mouse, trimmer, speaker, remote).
Take photos before opening.
Guess where the battery, motor, and PCB will be before you open it.
Open it carefully and note how it was held together.
Sketch where each component sits in the casing.
Write down why you think each part is placed there (balance, heat, assembly flow).
Identify the connectors: JST, ribbon cable, pogo pins, solder.
Note possible failure points: battery swelling, overheated PCB, broken wires, routing.
Compare with a premium product in the same category.
Log everything in a teardown journal with photos, sketches, and redesign notes.