EtrenankUS models and electrical market
Cordless-tool battery voltage vs amp-hours: what each number means
Separate battery-system voltage from capacity, compare labels correctly, and avoid turning amp-hour ratios into unsupported runtime promises.
Voltage and amp-hours answer different questions
Voltage identifies the electrical platform or class in which a battery is intended to operate. Amp-hours describe stated charge capacity. Neither number, by itself, confirms physical compatibility or guarantees how long a particular tool will work. DeWalt, for example, markets its 20V MAX system while disclosing that the nominal voltage is 18V [1]. That marketing-versus-nominal convention must not be used to declare another 18V battery interchangeable.
What an Ah comparison can establish
Within the same compatible platform, a stated 5Ah pack stores more charge than a stated 4Ah pack. Five divided by four is 1.25, so the label capacity is 25% higher. DeWalt identifies the DCB205 as a 5Ah battery [2]. This arithmetic compares labels; it is not an Etrenank runtime test and does not promise 25% more completed work.
| Label | Useful meaning | Does not prove |
|---|---|---|
| Voltage | Electrical platform or operating class | Connector fit across brands |
| Amp-hours | Stated charge capacity | Power, speed, weight, or exact runtime |
| Watt-hours | Voltage multiplied by amp-hours as an energy measure | Tool efficiency or work completed |
Why runtime does not scale as a universal promise
Tool load, motor control, pack temperature, age, cell behavior, duty cycle, and cutoff logic all affect usable runtime. Manufacturer comparisons may apply only to a stated test or baseline. Makita documents BL1830B as an 18V LXT 3.0Ah pack with a 30-minute charge claim on its rapid system [3]; that charge-time statement is not a runtime claim for every tool. Compare exact conditions before repeating a percentage.
A safer shopping sequence
- Confirm that the exact pack belongs to the tool's documented platform.
- Compare capacity only among packs already confirmed compatible.
- Check dimensions and weight when the catalog or manufacturer provides them.
- Confirm the exact charger and its pack-specific charge table.
- Treat performance percentages as manufacturer claims with their stated baseline, not universal results.
Use Etrenank's comparison table for recorded specifications and its compatibility finder for documented relationships. If a value has not been measured or sourced, it should remain unknown rather than be estimated from the label.