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Two tariffs, and batteries to remember them

Brennenstuhl Primera-Line PM 231 E, two tariffs, LR44 backup cells

A plug-in energy meter showing voltage, frequency, current, power factor and power, with two settable tariffs and three LR44 cells for data retention.

Brennenstuhl Primera-Line PM 231 E plug-in energy meter

Brennenstuhl Primera-Line PM 231 E, two tariffs, LR44 backup cells

A plug-in energy meter showing voltage, frequency, current, power factor and power, with two settable tariffs and three LR44 cells for data retention.

Measurement range
Nowhere in the listing
Low-load accuracy
Nowhere in the listing
Maximum current
Nowhere in the listing
Displayed values
Voltage, frequency, current, power factor and power, first bullet; the measuring time in hours and minutes, fourth bullet
Memory retention
Three LR44 cells included for data retention during a power cut, fifth bullet — the only meter in this family to ship them
Tariff calculation
Two individually settable tariffs, day and night, third bullet
Socket type
Raised shock protection, second bullet
Amazon reference
B007459MH6 (same reference on 5 Amazon marketplaces)
EAN
4007123598083
  • Three backup cells supplied, so a power cut does not erase a week of measurement
  • Two tariffs, which is what a day and night rate actually needs
  • No measurement range, accuracy or maximum current published

Best for: A long measurement on a day and night tariff that should survive an outage.

≈ €13
Check price on Amazon

Specifications

Measurement range
Nowhere in the listing
Low-load accuracy
Nowhere in the listing
Maximum current
Nowhere in the listing
Displayed values
Voltage, frequency, current, power factor and power, first bullet; the measuring time in hours and minutes, fourth bullet
Memory retention
Three LR44 cells included for data retention during a power cut, fifth bullet — the only meter in this family to ship them
Tariff calculation
Two individually settable tariffs, day and night, third bullet
Socket type
Raised shock protection, second bullet
Amazon reference
B007459MH6 (same reference on 5 Amazon marketplaces)
EAN
4007123598083

A meter built for the measurement that lasts a week.

The batteries

Three LR44 cells, supplied, to hold the data through a power cut. Across seven plug meters in this family, one ships them.

That is the difference between a spot check and a real measurement. A fridge measured over a week gives an answer you can act on, and a power cut on the fifth day erases it on any meter that forgets.

Two tariffs

Day and night, individually settable. Anyone on a split rate has two numbers to work with, and a meter with one tariff can only ever be half right.

What it shows

Voltage, frequency, current, power factor and power. Plus the elapsed measuring time in hours and minutes, which is what turns a total into an average.

Power factor is unusual on a plug meter and useful on a motor or a switching supply, where the current drawn is higher than the wattage implies.

The lines this listing leaves blank

A measurement range. An accuracy figure. A maximum current. Three of the seven lines, on a meter that is otherwise carefully thought out.

Availability

German Amazon store quoted about 13 € when this page was compiled.

British Amazon store carries it too, priced in its own currency, which the euro range above deliberately omits.

French, Italian and Spanish Amazon stores wanted more than 1.6× what the cheapest country wanted. A margin that wide usually means stock shipped in from elsewhere rather than a seller on the ground, so those quotes stay out of the range above.

American Amazon store returned nothing at all, so the buy button there runs a search instead of landing on an empty page.

These figures are what Keepa reported on the day this page was last updated. Availability and pricing move without notice.

Prices quoted in this text were read on 16 September 2026. The live price is at the top of the page.

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