Start with the equipment voltage window
A useful battery brief begins with the voltage the equipment can actually accept. Record the minimum operating voltage, the normal input range and the maximum permitted input, including any transient limits. A product described as a 24V system may contain electronics with a narrower window. Nominal battery voltage alone does not establish compatibility. Ask the pack supplier to state the intended chemistry, series configuration, fully charged voltage and discharge endpoint together, then compare that complete window with the equipment specification.
Measure the load before choosing capacity
Capture continuous current, short peaks, startup events and idle consumption. State how long each peak lasts and how often it repeats. A motor that starts once per shift creates a different requirement from one that accelerates every few seconds. Capacity in amp-hours describes charge; it does not prove that the pack, protection electronics, wiring and connector can deliver the required current. Include the charger and equipment input behavior in this review so that power requirements are assessed as a system.
Turn runtime into an energy target
Use watt-hours when comparing packs with different voltages. For an illustrative device consuming an average 30W for four hours, the load needs 120Wh before conversion losses and reserve are considered. That example is a planning calculation, not a promised runtime. Specify the allowed shutdown point, expected ambient temperature and capacity needed at the end of the intended service period. These assumptions help the supplier propose a capacity target and test method instead of simply offering the largest mAh number.
Send a usable mechanical drawing
An outer box dimension is only part of the available space. Show mounting points, connector access, cable bend space, nearby heat sources and any areas that must remain clear. Identify whether the pack will be enclosed in the equipment or exposed to handling. Provide the desired mass limit and service access approach. Do not assume that a shrink-wrapped prototype will have the same dimensions or environmental protection as a production enclosure. Request an agreed drawing before freezing the equipment housing.
Define what will count as acceptance
Build the RFQ around evidence: a controlled specification, drawing revision, sample quantity, required destination-market documents and an agreed validation plan. Separate existing model data from requested custom features. Ask which operating limits are guaranteed and which values are typical. Plan to test samples in the actual equipment across representative loads and temperatures. Jetray lists custom lithium-ion packs on its public website; a project-specific discussion should confirm the configuration, protection, documentation and commercial terms for the proposed model. Include a simple table of mandatory requirements so alternative proposals can be compared against the same equipment needs.
Sources & further reading
Prepared for the lithium-ion battery packs collection. General engineering guidance does not replace a model-specific datasheet or application validation. Source review: 4 November 2026.