Electrical basics
Read the specs that need to agree
Volts, amps, amp-hours, and the checks that a nominal voltage label cannot answer.
Nominal voltage is not maximum voltage
Nominal voltage describes the battery at a representative operating level. Fully charged voltage depends on chemistry and series count. Compare the documented charged voltage with the controller input limits, and confirm the low-voltage cutoff separately. Do not infer chemistry from a “48 V” label.
Keep the two current limits separate
Controller battery current and motor phase current describe different quantities. Compare the controller’s configured battery-current limit with the documented continuous whole-pack and BMS limits. This comparison does not establish the ratings of connectors, wiring, protection, or cooling.
Record programmable-controller settings
For VESC-based and Grin controllers, choose the exact hardware, then open Controller settings in its build details. Record battery, motor/phase and battery regeneration limits separately. Advertised burst current is not a battery-current setting. Regeneration sends energy back into the pack, so it needs documented battery/BMS acceptance and voltage headroom at full charge. Saving here updates the plan; programming and verifying the controller remain separate.
Use watt-hours to describe energy
Nominal volts × amp-hours gives an approximate nominal energy in watt-hours. For example, a battery documented as 36 V and 10 Ah represents about 360 Wh. That is stored energy, not a promised distance: speed, hills, rider input, load, temperature, and system losses affect a ride.
Matching plugs are only the beginning
Record the exact connector, polarity, pinout, and system protocol. Confirm the manufacturer-supported battery/charger pairing, including chemistry and permitted charge current. A connector that fits mechanically can still be the wrong electrical connection.
How to read planner results
“Checked dimensions agree” means only that the named comparison passed for the selected variants. “Specs needed” stays unresolved; “Review needed” marks installation details or interfaces without an automatic check. Catalog selections carry their specifications and source links; custom values are supplied by the builder. A passing check does not certify the whole bicycle.
Source material
Manufacturer examples explain the checks; their model-specific limits do not apply to every e-bike.