Notes On Fault Causes During Battery Testing - AR54.10-D-1129-06A

Model 414, 415, 420, 447, 448, 636, 638, 639 

Model 601, 602, 611 

Model 667, 668, 669, 670 

Model 900, 901, 902, 903, 904, 905, 906, 909 

Model 907, 910 

Notes on possible errors when checking battery with Midtronics MCR 717 

Carrying out the battery test incorrectly may lead to a false statement about the battery condition.

When testing batteries using the Midtronics tester MCR 717, be sure to observe the following information:

• Technical equipment condition 

  Incorrect measurements may also result if measurement cables or terminal clamps are no longer in their original condition. The terminal clamps used here are special "Kelvin clamps". Only the original terminals may be used.

  The device does not necessarily need to be sent in for repair if the clamps are defective. Defective terminals can be replaced separately, although if part of the line in front of or in the terminal is damaged, the whole device must be sent in.

• The Midtronics MCR 717 must always be connected directly to the battery 

  It is not necessary to disconnect the poles on the battery for the measurement. The measurement takes place directly at the battery and must not be carried out at other points, such as at the jump-start connection point.

• Entering incorrect data on the Midtronics MCR 717 will falsify the measurement result 

  All entries on the Midtronics MCR 717 must be performed diligently.

• Charge and test again 

  Batteries that have been tested and have returned the measurement result "Charge and test again" must be charged fully  before they are tested again.

  A partial charge is not enough to obtain a reliable evaluation of such batteries.

• After batteries have been charged, they must always be loaded first before testing is performed 

  After charging, the batteries have an increased surface voltage. This distorts the measurement result or leads to a fault message. After charging, always load the batteries for approx. 2 minutes or allow them to rest for several hours. To load them, turn on the low-beam headlamps, for example, and then allow the battery to rest for 5 minutes.

Auxiliary batteries 

The Midtronics MCR 717 is only designed for testing starter batteries. Some additional batteries (e.g. traction battery) are designed for current consumption over extended periods. No cold cranking amps are therefore specified on these batteries - only the open circuit voltage can be tested.

Measurement of the open circuit voltage is a simple and effective method of checking the condition of the additional battery (e.g. traction battery).

Camper vans are generally equipped with a voltmeter for the measurement.

Open circuit voltage → charge level 

• > 12.80 V → 100 %
• Approx. 12.55 V→ 75 %
• Approx. 12.30 V → 50 %
• Approx. 12.20 V → 25 %
• < 12.00 V → 0 %

The measurement should take place at an ambient temperature of between 20 and 25°C and a few hours after charging has been completed.