Check The Maintenance-Free Batteries - Kärcher BR 45/40 Service Manual

9.4.15Check the maintenance-free batteries

The battery must be fully charged prior to the inspec-
tion to obtain a reliable result.
The following checks must then be made:
Measurement of the idle voltage
The idle voltage provides a measure for the charging
status of a maintenance-free battery.
If this value is below a certain limit, this indicates that
the battery is not charged.
You can estimate the approximately available charge
from the idle voltage.
The following values apply with:
Exide gel batteries
12 volt block battery
> 12,80 Volt
> 12,55 Volt
> 12,32 Volt
> 12,18 Volt
> 12,00 Volt
The idle voltage should reach at least the following
limit value:
12 volt block battery = min. 12.30 volts
–
If these values are not met, the battery must be
charged first.
Measuring the battery voltage under load
Note
The battery terminals must be checked prior to the
load test.
The battery terminals must always be clean and tight.

Switch the appliance on and take the suction tur-
bine and the cleaning head into operation on an in-
sensitive floor.
Important: The consumers must run continuously
during this test.
The load test can also be performed while the suc-
tion turbine is turned on.

Use a voltmeter / multimeter to measure and
record the battery voltage of every individual bat-
tery block.
Measure the current using a clip-on ammeter dur-
ing the voltage measurement and record it.

The battery block with the lowest battery voltage
must be replaced if it is outside the tolerance val-
ues.
See item "Limit value of battery voltage between
the individual battery blocks".
86
English 5.906-269.0 Rev. 00 (03/11)
If this procedure still does not indicate clearly that
there is a faulty cell, the third measurement must be
performed after the second load test.
Measuring the battery voltage under load until
the appliance shuts off


Result
Charge ap-
In case of a problem, one or more battery blocks /
prox.
battery cells will be significantly different from each
other so that the fault can be pinpointed without
100 %
doubt.
75 %
Limit value for battery voltage between the indi-
50 %
vidual battery blocks
25 %
With all measurements, the different must not exceed
Deep discharge the following voltage under load:
Exide batteries
–
Use a voltmeter / multimeter to measure and
record the battery voltage of every individual bat-
tery block.
Measure the current using a clip-on ammeter dur-
ing the voltage measurement and record it.
Operate the appliance until the discharge end volt-
age / the total discharge protection shuts the appli-
ance off.
between the 12 volt battery blocks 0.2 volts