General Technical Information


The following accessories and/or specific performance characteristics are available for our battery chargers.

In addition, further performance characteristics not listed here can also be integrated to meet your personal requirements - simply contact us directly or send us an email.

Name Abbreviation Description
Electrolyte circulation EU EU lowers the charging time by approx. 2-3h (intermediate charging also possible)
Pulse charging Puls Pulse charging reduces the charging time by approx. 1-2h
Temperature compensation T The charging voltages are adjusted to the batterie temperature
Display D All charging data can be called up on an LCD display
"On Board"-version O This version is especially designed for assembly in vehicles
Changing capacity K The charger can be switched over to meet a variety of battery capacities in keeping with customer requirements
Forced ventilation (fan) F Should the device be set up in a room without circulating air, so-called forced ventilation will be required
Aquamatic A The charger can be fitted with a pump control system which ensures water is topped up automatically
Special design S We also produce individual customised models
Text acc. to DIN 41774

Semiconductor rectifier equipment with W-characteristic for loading lead-acid batteries

Text according to DIN 41774

Static power convertors; semiconductor rectifier equipments with W-characteristics for charging of lead-batteries; guide-lines
Edited by FNE / VDE joint committee 221.2/0556.
This standard treats rectifiers with W-characteristics (see DIN 41772) for fully charging lead acid batteries with liquid electrolyte. The course of the W-characteristic should guarantee the required current reduction for lead acid batteries during charging.


1. Basic requirements

To protect the battery the W-characteristic must be conducted so that the limits of the charging currents for gassing and charging voltage laid down by the battery manufacturers are not exceeded. Peak values for the charging current after attaining the gassing voltage for different cell designs are specified in VDE 0510/8.70 § 13. Considering these currents the shortest possible loading time arises in charging with W-characteristics.
The following specified values of the charging current are the upper limits, which must not be exceeded when loading with W-characteristics, otherwise damage may occur to the battery due to excessive gassing. However, it is permitted to load lower currents than those specified in this standard, which result in longer loading times.
For small batteries and starter batteries, there is often no need to load with the maximum charging current, because enough loading time is available. If small chargers are manufactured for this purpose with a nominal current lower than specified in Section 2.2, and its characteristic is steeper than indicated on the diagram in section 2.1, then they do not meet this standard and may not be identified under this standard reference.

Note: To prevent damage to the battery, it is to be noted that small devices do not exceed the limits in accordance with Sections 2.1 and 2.2.

1.2. After reaching full charge (see DIN 40 729), the batteries must be turned off by hand or automatically.

2. Characteristic

2.1. Process

The process of the W-characteristic is determined by three variate pairs of current and voltage:

a) Nominal unit current at 2 V/cell
b) 50% of the nominal current of the devices at 2.4 V / cell (gassing voltage)
c) 25% of the nominal current of the devices at 2.65 V/cell.

A tolerance of ± 0.05 V/cell is allowed for the voltage values.
The image (figure 1) shows the process of the W-characteristic and the tolerance field.


Figure 1

2.2. Nominal current of devices
The nominal unit current (charging current at 2 V / cell) must not be larger than the charging of the permissible starting current of the battery to be charged when loading with W-characteristic. The VDE 0510/8.70 provision § 13b) gives maximum values of charging currents permitted for the different cell designs with gassing voltage (2V/cell), with regard to a nominal capacity of the battery of 100 Ah. Due to the established process of the W-characteristic in section 2.1, the initial charging current permitted here is twice as large as the permitted charging current with gassing voltage The following related values of the initial charging current l'g arise for the current standard lead accumulators.

Lead accumulatorsg Initial charging current I´g with regard to a
Cell design DIN nominal capacity of 100 A h
GiS, PzS 43 567 16 A
Gro (vehicle) 28 A
Gro (stationary) 40 730 24 A
OPzS 40 736 14 A
OPzS 40 737 14 A
Starter batteries 72 311 24 A

Table 1


For a certain type and size of battery, the nominal current of the devices results in IdN for


Formula 1

2.3. Nominal voltage influences
Devices with W-characteristic are generally not equipped with means for automatic compensation of line voltage fluctuations, so that the output current depends on the fluctuations of the mains voltage. The relative power fluctuations increase with decreasing flow. A 5% increase in main voltage increases the current at 2 V / cell to about 15%, at 2.4 V / cell to about 30% and at 2.65 V / cell to about 50%. That is why, especially after exceeding the gassing voltage (2.4 V/cell), main voltage excess from just 5% for a longer duration of five minutes is detrimental for the battery.
To avoid battery damage, the device of the excessive supply voltage, e.g. at night, with the help of the transformator taps (see Section 3.2), must therefore be adapted.
With charge switches of which the W-characteristics is generated with inductors (charging inductors, constant-current transformer), a dependence of the charging current on the mains frequency is also available. This dependence affects an inclination change of the characteristic. In networks with a maximum frequency variation of 5%, this influence is negligible.


3. Guidelines for development

3.1. In rectifiers devices for charging batteries the DC side must be galvanically separated from the mains side (see VDE 0510). Therefore, only rectifier transformers with separate windings may be used.

3.2. The transformers must have taps for -5%, 0%, +5% and +10% of the mains voltage so that the devices can be adjusted to the mains voltage. In devices with a nominal power up to 500 W, the taps can be omitted.

3.3. The chargers must be so adjusted that they can be continuously loaded with at least 80% of the nominal current.

3.4. Current measuring devices of chargers need to display the arithmetic mean (using moving coil or moving magnet current measuring device). Moving iron current devices display the effective value of the charging current which is higher than the arithmetic mean. If moving iron current measuring devices are used in the chargers, then they must be provided with a scale for the appropriate direct current average. They are only allowed for simple chargers with non-adjustable W-characteristic. If such moving iron current measuring devices are used, this should be stated explicitly.

3.5. If devices for different types of cells are switchable and/or adjustable or switchable for different initial charge currents, then any possible characteristic of the process must be kept according to the image on page 1.

3.6. If secure screws are installed on the direct current side, then the cable on the threaded ring leading to the output side of the device must be connected.

4. Guidelines for the operation

4.1. VDE 0510/8.70 § 10 and § 12 applies for the installation and operation of chargers.

4.2. The resistance of the cables between the charger and the battery can affect the characteristic inclination and thus the amount of the charging current. If necessary, the device characteristic is to be adjusted, e.g. by changing the setting of the charging resistor, the charging inductor or the transformator control.

4.3. Loading several parallel batteries from a charger with a W-characteristic is not permitted after passing the gas voltage, because compliance with the limits for the single battery is not guaranteed.

4.4. Charging several batteries connected in series is only permitted if the specified limits of the charging currents for the smallest battery are not exceeded and each fully charged battery is turned off. Series connection is only to be recommended for small accumulators and starter batteries.

Text acc. to DIN 41773

Semiconductor rectifier equipment with IU-characteristic for loading lead-acid batteries

Text according to DIN 41773

Static power convertors; semiconductor rectifier equipments with IU-characteristics for charging of lead-acid batteries; guidelines

1. Applicable standards and documents
DIN 57510/VDE 0510 VDE provision for accumulators and battery systems VDE 0100 Regulations for the erection of electrical power installations with nominal voltages up to 1000 V

2. Basic requirements

2.1 To protect the battery, charging in constant voltage supply (U-part) of the characteristic must be ensured that no vital gases occur, yet the required acid concentration in the available loading time is accomplished as much as possible. On the one hand, the voltage must therefore not exceed the determined maximum value of the battery manufacturer at the terminal of the batteries. On the other hand, it should also not deviate significantly from this value, since to achieve the necessary charging time for achieving the required acid density is the shorter, the less the voltage at the battery terminals is under the allowable maximum value. The permitted maximum value of the voltage is between 2.33 and 2.40 V per cell depending on battery type and operating conditions.

2.2 A battery connected to constant voltage according to section 2.1 takes a current that is determined by the capacity of the battery and its charging and operating status. If the maximum value of the voltage explained in section 2.1 is kept, the current with a faultless battery, in general, cannot become so large that the battery is endangered. The battery does not require any automatic current limitation by the charger. This is necessary to protect the charger and the system (I part of the characteristic). The battery also does not place any demand on the tolerance of the current limiting. The narrower the tolerance of the current limiting, the more secure the full electrical output of the charger will be used for reducing the loading time (especially when loading multiple batteries in parallel).

2.3 When charging with a constant voltage in accordance with Section 2.1, the currents picked up by the battery during charging subsides at small values, so that the full-charge state is reached only after some time. To shorten the charging time it is permissible to increase the charging voltage of a current value specified by the battery manufacturer above the listed limits in Section 2.1 according to a W-or I-characteristic (IUW or IUI).

2.4 The charging current emitted from the rectifier device is superimposed on an alternating current. Value and flow of the alternating current are given by the DC voltage with superimposed AC voltage, if necessary, the smoothing equipment and the battery load. The superimposed alternating voltage depends primarily on the circuit (pulse rate) of the rectifier and possibly the type of control or voltage adjustment (head angle). (For details see DIN 41 755 Part 1). The superimposed alternating current is divided inverse ratio of the internal resistance of the battery when charging in parallel. In the parallel charging of batteries of approximately same capacity and plate size, this alternating current is distributed almost equally between the connected batteries, and rater quite independently of their charge state. As a result, the nearly fully-charged batteries that take up only a small direct current are impinged with an almost pure alternating current. The alternating current must not be so large that an unacceptable rise in temperature arises in the the electrolytes. This is guaranteed in general, if in parallel charging of multiple batteries, the current flowing through the individual battery alternative current component (in mixed flow with direction reversal) in the charge current is not greater than 1.5 X is I5. (I5 is the five-hour discharge; see DIN 57510/VDE 0510).

3 characteristics

3.1 Strict adherence to the highest voltage value according to section 2.1 and the current limiting under Section 2.2 is achieved by an IV-characteristic according to DIN 41 772 The tolerances to be kept for an IU characteristic according to these guidelines are
specified in image 1.
Devices with these characteristics allow one to charge multiple batteries of the same number of cells, different capacity and different charge state in parallel.

3.2 Except for devices with IE characteristic in image 1, devices with characteristics according to images 2 and 3 are permitted with the following restrictions.

3.2.1 Devices with characteristic according to images 2 and 3 allow for faster full charging by increasing the voltage across UZL beyond the end of charging. This voltage increase may only be used if the charging current has reached the limits mentioned in section 12.2.2, DIN 57 510/VDE 0510, published January 1977.
As part of the IU-characteristic several batteries may be charged simultaneously (see Section 3.1). When increasing the voltage on the values mentioned in section 2.1, the parallel connection of the batteries must be separated and charging must be done in the W-component or second I-component as individual charging. Charging multiple batteries connected in parallel in the W or second I component is not permitted; unless it is ensured through appropriate measures, that the current consumption exceeds the limit of any of the batteries according to DIN 57 510/VDE 0510. Upon reaching the full charge the batteries must be turned off.

3.3 The tolerance fields according to the images 1 to 3 should be kept at mains voltage variations of + - 10% and power frequency voltages of + - 2%. For devices that are not measured for these fluctuations, the allowable limits must be specified by the manufacturer. In private power supply networks, in contrast, larger fluctuations in the mains voltage and frequency can occur during a longer period of time. Where this is the case, it must be communicated to the device manufacturer when ordering.

4 Electrical properties and structure of the Chargers

4.1 DThe superimposed alternating current, which is delivered by the rectifier device at rate data, is to be specified by the manufacturer in the data sheet.

4.2 If oscillations or relaxation oscillations occur in the part of the U-characteristic, which do not subside damped, then the current may not exceed the limits mentioned in section 2.4 and the instantaneous value of the oscillating voltage 2.45 V per cell.

4.3 To adjust the charging voltage specified under section 2.1 within the limits of 2.33 and 2.40 V per cell, a charging voltage adjuster is required. This should be arranged so that it is not accessible to unauthorised persons.

4.4 With charging rectifier devices, the direct current must be galvanically separated from the alternating current, if a protection measure is not applicable in the direct current circuit according to VDE 0100 (see DIN 57 510/VDE 0510).

4.5 Current measuring devices for displaying the charging current must display the arithmetic mean (e. g. moving-coil current measuring devices).

4.6 With regard to the connection of deeply discharged batteries, the unit must be measured so that it can also be operated with a mains overvoltage of 10% and a battery voltage of 1.8 V per cell, without suffering any damage (see VDE 0556, issued October 1966, § 58d), VDE 0557, edition March 1969, 54d), 57510/VDE DIN 0510, DIN 57 558 part 1/VDE 0558 Part 1, published August 1977, Section

5 Guidelines for the operation

5.1 For chargers with IU characteristic in accordance with Section 3.1, the batteries may be connected for up to 3 days. If however, the steady-state value of the charging current does not exceed 10% of I5, it must be turned off after reaching the maximum allowable acid temperature.

5.2 If the time available on work days for fully charging is not enough, then an equalisation charge must be carried out once a week.
When fully charging on work days, the equalisation charge prescribed by the battery manufacturers is also enough in intervals of four weeks.
Equalisation charge (see DIN 40 729) can be carried out with chargers in accordance with Section 3.1 through prolonged loading (e. g. on Saturday / Sunday) or by charging beyond the voltage limits specified in section 2.1. (e. g. with chargers according to section 3.2.1). In the latter case, charging is to be monitored under the provisions of the battery manufacturer, insofar as chargers with automatic disconnection are used.

5.3 For measuring the connecting cables between the charger and battery it is desireable that the voltage drop at the rated data current does not exceed 2% of the nominal voltage. This does not apply if the voltage drop is regulated by the charger. The cable between the distribution parts and batteries must be kept as short as possible, if an extension of the charging times should be avoided.

5.4 When charging devices in accordance with section 3.1 and section 3.2, weekly acid density and acid temperature of every cell must be measured in order to detect arising plate shot.

5.5 When charging according to IU characteristic it is particularly important that the batteries are in good condition and that their cells are not discharged unequally.

5.6 For testing the voltage in the U-part of the characteristic, a voltage measuring device is used with a measurement uncertainty of no more than + - 0.01 V per cell.

Bild 1

Image 1

IU-characteristic with tolerance field (see section 3.1). I5 adjustable continuously or in at least three positions from 2.33 to 2.40 V per cell.

Bild 2

Image 2

IUW-characteristic with tolerance field (see section 3.2.1). UZL adjustable continuously or in at least three positions from 2.33 to 2.40 V per cell.
X Current limit (see DIN 57 510/VDE 0510, issue January 1977, Section 12, 2.2)

Image 3

IUI-characteristic with tolerance field (see section 3.2.1). UZL adjustable continuously or in at least three positions from 2.33 to 2.40 V per cell.
X Current limit (see DIN 57 510/VDE 0510, issue January 1977, Section 12.2.2)

UZ cell voltage, UZL constantly kept value of charging voltage per cell, charging current IL and IDN nominal DC current of the device. The nominal DC voltage is 2.0 V per cell. The tolerances of the I-part of the characteristic in images 1 to 3, in all cases, can be greater than + - 2%, without thereby endangering the battery. In this case, according to DIN 41 772, the tolerance must be specified.

Fuse protection for Battery Chargers

How to fuse protect battery chargers correctly!

Tripping characteristics from B, C and K circuit breakers

To ensure trouble-free use of battery chargers, circuit breakers are required which have a K characteristic or delayed-action screw-in fuses.

Circuit breakers with B and C characteristic for cut-out protection

Tripping characteristics acc. to DIN VDE 0641 Part 11
Rated currents 6 ... 63 A in 10 graduations and/or 0.5 ... 63 A in 17 graduations. The introduction of these characteristics enables the automatic cut-out switches to be assigned directly in accordance with the permissible rating for insulated lines pursuant to DIN VDE 0298 Part 4/2 88 as the second condition is automatically met (12 = 1.45*In).

Circuit breakers with a K characteristic for cut-out protection and appliance protection

Tripping characteristics pursuant to DIN VDE 0641 Part 101
Rated currents 0.5 … 63 A in 17 graduations and/or 0.2 … 63 A in 20 graduations. Motor protection and transformer protection is achieved by selecting a rated current that matches the motor or transformer data. The electromagnetic trippers have been set in such a manner that the inrush current for the motors and the starting currents of the transformers cannot cause unwanted shutdown. In circuits with groups of incandescent lamps, parallel compensation fluorescent lamps or other discharge lamps, the conductor cross-section that needs to be protected can be exploited more efficiently than is possible when using circuit breakers with the same rated current and tripping characteristics B and C with regard to the starting currents. As with B and C characteristics, the K characteristic also allows for the automatic cut-out switches to be assigned directly in keeping with the permissible rating of the insulated lines pursuant to DIN VDE 0298 Part 4/2.88. This guarantees enhanced cut-out protection as the major testing current I2 is 1.2*In and therefore lower than 1.45*In.

Auslöse-Charakeristik B


Auslöse-Charakeristik C


Auslöse-Charakeristik K


Connection instructions
  • Check the mains supply!
    Screw-in fuse:
    Example: T 16 A, delayed-action circuit breaker: K 16 A
  • Supply voltage:
    If the fuse is OK, it must be possible to measure the supply voltage 1 ph or 3 ph at the mains socket and at the device input. The devices are supplied with Urated: 230V~/400V~. This will need to be adjusted if a higher voltage exists.
  • Device input:
    If the supply voltage is OK, the battery charger can be switched on. The LED ERROR lamp will light up and the words "Battery missing" will appear in the display.
  • Polarity::
    Check the polarity of the charger plug, the battery charger and the battery.
  • Connect the battery:
    The LED "MAIN CHARGE" lamp will flash for approx. 5 secs. then stay on permanently to indicate that the charging process is beginning. When taking check measurements, always remember: only take readings during the charging process.
    1. Supply voltage
    2. Charging voltage
    3. Charging current
    In the event of any malfunctions, check all of the battery connections. Otherwise, please observe all of the special instructions for the battery chargers and battery.


Recharging time

Description of the controlled recharging time for W-characteristic chargers

The main reason for recharging wet-cell lead-acid batteries is to mix acid. If the battery plates have been charged but the charging current continues to flow, the water will be electrolysed to some extent. The gases which are released in the process cause the acid to mix. The recharging process should be stopped once the acid mixes so as not to damage the battery. The IEB-FILON CLASSIC battery switches regulate the recharging process in such a way that it adjusts to the preceding discharge.


Using the IEB-FILON CLASSIC battery switches, the charge factor (CF) can be pre-set to match the battery used. The CF is kept constant during each charge. For your battery, this means:

Bild 2

Example 1:
240Ah battery - 80% discharge = 192Ah
Charging with CF 1.2 -> 192 Ah - Main charge + 20% - Recharge = 230Ah Total charge

Example 2:
240Ah battery - 20% discharge = 48Ah
Charging with CF 1.2 -> 48 Ah - Main charge + 20% - Recharge = 58Ah Total charge

Casing Types


Filon Classic

Type Width Height Depth Hole spacing
KL 200 305 200 210 265
KL 300 365 235 260 320
KL 350 520 460 385 480
KL 400 520 700 385 480
KL 500 700 960 500 670



Filon Futur

Type Width Height Depth Hole spacing
HF 90 177 69 112 - - -
HF 180 260 164 93 230
HF 190 260 164 113 230
HF 210 268 244 115 245
HF 450 430 256 115 350
HF 455 430 393 157 350
HF 460 295 491 133 215
HF 550 430 395 300 350
HF 560 430 482 300 350
HF 650 430 695 300 350
HF 750 430 790 300 350