01 · QUESTION / INTENT
Build a cell shortlist from operating duty, system architecture and contractual obligations—not from capacity alone.
02 · DIRECT ANSWER
Start with the project duty cycle and end-of-life energy commitment. Screen cells for voltage window, continuous and pulse current, thermal range, dimensional integration, degradation evidence and supply continuity. A cell is selected only after pack/BMS modelling and sample validation show that the system can meet the guaranteed operating envelope.
03 · DECISION TABLE
| Decision factor | Decision direction | Confirm before approval |
|---|---|---|
| Duty cycle | Match C-rate, depth of discharge, dwell time and cycles per year. | One-line diagram, dispatch profile and worst-day profile. |
| Thermal envelope | Check hot spots and low-temperature power, not ambient temperature alone. | Cell heat data, cooling concept and rack temperature spread. |
| Life commitment | Model calendar plus cycling degradation against end-of-life energy. | Test conditions, warranty definitions and augmentation plan. |
04 · ENGINEERING EXPLANATION
Convert the AC use case into a DC cell envelope: usable SOC window, current profile, cell count, parallel paths, temperature distribution and control limits. Then run tolerance and ageing cases so the weakest permitted cell—not the average fresh cell—still stays inside voltage and temperature limits.
05 · APPLICATION / MARKET MAPPING
Four-hour utility storage usually rewards energy density, consistency and long-life operation; high-power grid services may shift weight toward current capability and thermal response. Hot climates and constrained sites need separate cooling and derating cases.
06 · EVIDENCE AND TEST CONDITIONS
- Controlled cell specification, drawing, lot traceability and change-notification process.
- Cycle/calendar-life data with temperature, SOC window, C-rate, EOL threshold and sample definition stated.
07 · RISKS / NOT SUITABLE WHEN
- Do not select on Ah, cycle count or price without equal test conditions.
- Not suitable when pack voltage, cooling, BMS limits or the warranty envelope are still undefined.
08 · FAQ
Is 314 Ah automatically better than 280 Ah?
No. It may reduce cell count, but integration, thermal gradients, duty and qualification effort can outweigh that benefit.When should samples be ordered?
After paper screening and before detailed pack freeze, with a written test plan and acceptance limits.BUYING COMMITTEE ANSWERS
Engineering
Fit is proven by pack/BMS/thermal modelling plus samples under the real duty cycle.Procurement
Request quote basis, MOQ, lead-time assumptions, capacity allocation and change control together.Quality
Lock model identity, production site, lot coding, incoming limits and deviation approval.Compliance / Logistics
Map each document to cell, battery, shipment, destination and transport mode.Finance / Project
Use guaranteed usable energy, augmentation and downtime—not purchase price alone—in the base case.Management
Approve design-in when evidence timing matches the project gate and supply strategy.10 · PROJECT CTA