What Do Battery Size Charts Mean?
Battery size charts are standardized references detailing physical dimensions (e.g., length, diameter), electrical specs (voltage, capacity), and chemistry type (Li-ion, NiMH). They ensure compatibility across devices, from AA cells to EV modules. Key metrics like milliampere-hours (mAh) and watt-hours (Wh) define runtime, while form factors (cylindrical, prismatic) dictate fitment. Charts follow ANSI/IEC codes (e.g., 18650 = 18mm x 65mm) for cross-manufacturer consistency.
What parameters do battery size charts include?
These charts list physical dimensions (length/diameter), nominal voltage (3.7V Li-ion), and capacity (mAh/Wh). Additional data includes terminal type, weight, and chemistry. For EVs, charts may specify module/pack dimensions and energy density (Wh/kg). Pro Tip: Always cross-check ANSI/IEC codes—a “CR123A” might be 17mm wide, while “CR17345” is 16.5mm, risking fit issues.
Beyond basic specs, advanced charts detail discharge rates (C-rating) and thermal limits. For example, a 21700 cell (21x70mm) offers 5000mAh at 3.7V, ideal for high-drain tools. But how do you compare prismatic vs. pouch cells? Prismatic types (e.g., EV modules) prioritize structural rigidity, while pouches (smartphones) maximize space efficiency. Transitioning from consumer to industrial batteries, charts add parameters like IP ratings and vibration resistance.
| Parameter | Consumer (AA) | EV (Module) |
|---|---|---|
| Voltage | 1.5V | 48V |
| Capacity | 2500mAh | 100Ah |
| Weight | 23g | 25kg |
How are battery dimensions and codes interpreted?
Codes like 18650 decode to size: 18mm diameter x 65mm length. ANSI/NEDA standards ensure global compatibility. Pro Tip: “R” in codes (e.g., CR2032) denotes round cells, while “F” indicates flat tops. Metric-imperial mismatches occur—some “AA” cells vary 0.1–0.3mm between brands.
Practically speaking, a 26650 cell (26x65mm) suits high-capacity flashlights, but swapping it into a 18650 device requires spacers. Ever wondered why some codes include letters? The “L” in LiFePO4 codes (e.g., LFP-100Ah) distinguishes lithium chemistries. Transitioning to packs, EV battery charts use codes like “P7S4” (7 parallel, 4 series cells), impacting voltage (14.8V) and capacity (21Ah).
| Code | Diameter | Length |
|---|---|---|
| 14500 | 14mm | 50mm |
| 18650 | 18mm | 65mm |
| 26650 | 26mm | 65mm |
What’s the difference between physical and electrical specs?
Physical specs (size/weight) ensure mechanical fit, while electrical specs (voltage/capacity) dictate performance. A 9V battery (physical: 48.5×26.5mm) outputs 9V but varies from 500mAh (alkaline) to 200mAh (Li-ion). Pro Tip: Higher Wh/kg means lighter batteries—critical for drones.
Consider this: Two AA batteries might both be 50.5mm tall, but a lithium AA provides 3000mAh vs. 2500mAh for alkaline. But what if your device can’t handle lithium’s 1.7V? Voltage compatibility is as vital as size. Transitioning to EVs, a 100kg battery pack with 100Wh/kg delivers 10kWh—enough for 60km in compact EVs. Always prioritize energy density (Wh/L) when space-constrained.
How do capacity and voltage interrelate in charts?
Capacity (Ah) multiplied by voltage (V) equals energy (Wh). A 12V 100Ah battery stores 1200Wh. Pro Tip: For solar systems, prioritize Wh over Ah—panels output variable voltages.
Imagine two 18650 cells: 3.7V 3000mAh vs. 3.2V 3500mAh. The first offers 11.1Wh, the latter 11.2Wh—nearly identical energy. But in series, the higher-voltage cell boosts total pack voltage. Transitioning to packs, a 72V 50Ah EV battery (3.6kWh) requires BMS balancing to prevent cell drift. Remember: Parallel connections increase capacity; series increases voltage.
What are common battery size standards?
ANSI C18 (US) and IEC 60086 (global) standardize codes like AAA (LR03) or 18650. EV modules follow ISO 12405-4 for dimensions/safety. Pro Tip: IEC codes (e.g., “CR” for lithium) clarify chemistry—avoid mixing LiMnO2 and LiFeS2 in devices.
For instance, IEC’s “CR2032” ensures 20mm diameter x 3.2mm height globally. However, some Chinese manufacturers label 3V cells as “CR2025” despite differing tolerances. Transitioning to industrial, UL 2580 certifies EV batteries for crash safety—charts list fire ratings and enclosure IP68 compliance. Always verify regional standards when importing batteries.
Battery Expert Insight
FAQs
Yes, but match voltage and chemistry. A 3.6V NiMH AA (size 15AA) can’t replace a 1.5V alkaline AA despite identical dimensions.
What if my battery isn’t listed in charts?
Measure dimensions/voltage and compare with OEM specs. Custom batteries (e.g., medical devices) often deviate from standards.
Do all 18650 batteries have the same capacity?
No—ranges vary from 1200mAh (LiFePO4) to 3600mAh (Li-ion). Always verify datasheets for actual specs.