7.1.2 Operation using standard batteries. Ahlborn ALMEMO 2790, MA2790BTFV

7. Power supply current consumption of 8 mA is approx. 230 hours. In sleep mode with a cycle of 1 minute it should be possible per battery charge to perform measuring operations for approx. 390 hours. By extending this cycle to e.g. 1 hour, this time can be increased to approx. 400 days.

Important : The operating time depends very much on the current draw of the sensor being used.

Charge status indication

The charge status of the rechargeable batteries is indicated by two LED colors

(see 1). The following table lists the LED activity and the associated battery charge status.

LED activity

OFF

Description

Mains unit not connected

Green Mains unit connected, batteries fully charged

Red Mains unit connected, batteries being charged

Important : Critical battery status is indicated by 'LOBAT' in the 2790's display.

(see 7.1.3).

7.1.2 Operation using standard batteries

Alternatively, it can be powered using standard commercially available AA batteries. We recommend using such batteries with a high capacity. Using lithium batteries (e.g. Energizer Ultimate Lithium LR91-FR6) the operating time can even be doubled.

7.1.3 Supply voltage monitoring

The operating voltage is displayed each time the device is switched on, thus allowing the user to estimate the remaining operating time. In the event of battery voltage falling below 3.4 V (with rechargeable batteries) or 3.2 V (with standard batteries), i.e. approx. 10 percent remaining battery capacity, the LOBAT arrow will appear in the display. Now, if rechargeable batteries are being used, the mains unit should be connected in order to recharge them - or, if standard batteries are being used, these should be replaced. Battery status can be monitored on the receiving device; this is activated by programming a measuring channel 'UbAt' on the 2790 within the first four channels transmitted and a limit value on the destination system. Alarm reporting can also be activated. To replace used batteries first unscrew the battery compartment cover

(6) on the rear of the device, remove the old batteries, and, observing correct polarity, insert the new.

7.2 Mains operation

The ALMEMO ® 2790 can be powered from an external source preferably using mains adapter ZA 1312-NA10 (12 V / 2A) connected at the DC socket (3).

12 ALMEMO ® 2790