LAMAR BETA D-50 Operating Manual - page 15

4. DETAILED OPERATING INSTRUCTIONS  

4.4.2   DISCHARGE TIME SETTING  

The discharge time is usually set to 60 minutes, after which a pass/fail signal is given 

based on whether the battery reached the cutoff voltage or not.  

To determine the full capacity of the battery a longer time can be set (several hours). The 

Beta D-50 will then continue the discharge test only until the cutoff voltage has been 

reached. The timer, cutoff voltage and discharge current displays will freeze at this point. 

The capacity can be calculated as the product of the discharge current and the time 

passed until the voltage cutoff was reached.  

C.

  SET TIMER  

Set the timer by pushing buttons up or down to the 

required discharge time (usually 60 minutes)  

CAUTION.

 For lead-acid batteries the time and voltage cutoff 

should be set with caution. If discharge continues too far 

beyond the point of exhaustion it may be harmful to the 

battery, unless the battery is soon to be recharged.  

4.5 CUTOFF VOLTAGE  

The Beta D-50 will automatically stop the discharge test when the cutoff voltage has  

been reached. The cutoff voltage is set so that if the battery voltage  is higher than the  

cutoff voltage when the discharge time has expired, the battery has passed the capacity  

test.  

4.5.1   LEAD-ACID BATTERIES  

Always refer to your battery manufacturer's maintenance manual for the most accurate  

information. For a 24 volt sealed lead-acid battery the cutoff voltage is usually set at 18  

or 20 volts when discharged one hour at a current equal to the 80% of the battery’s C

1

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rate. See table 4-2 for examples of discharge test settings for sealed lead-acid  

batteries.  

BETA D-50 TESTER / ANALYZER - OPERATING MANUAL V2.2 

Page 13