• Battery charger
  • primary switched
  • Case
12 V 12 A
24 V 6 A


Functional description
The chargers of the G25-300 series are designed in the primary switch mode technology. A constant DC voltage with low AC voltage component during the charging process ensures a maximum lifetime of maintenance-free lead batteries. As a standard, the charging of the battery follows an IUoU curve, 2nd stage charging with 10-hour timer.

Furthermore, an IUIa characteristic for batteries and maintenance-free batteries can be selected by a switch. Three built-in LEDs then indicate the following states:
  • Yellow LED: charging current is flowing (LED), battery charged by 90% (LED flashes)
  • Green LED: battery full charge
  • Red LED: malfunction
Mechanical design
All components are mounted on the PCB. The PCB is in a case made of plastic sides with cover plates, which are screwed against each other, and has aluminum front and back sides. Type 12 V 12 A has a temperature-controlled cooling fan built-in – applies for the series, for the prototype the fan is always in operation while charging.

The mains connection is made by a 2-pin plug. The devices comply with the protection class II.

CE marking
The devices meet the basic requirements of the law relating to electromagnetic compatibility (89/336/EEC EEC treaty) and the low voltage directive (73/23/EEC).


  • Current limiting, overvoltage protection, overtemperature protection
  • Short circuit protection, reverse polarity display
  • light weight, small dimensions
  • Charging of deeply discharged batteries
  • Derating at high temperature
  • Start a new charging cycle after a power reset or reconnecting a new battery.
  • Malfunction: LED «red», duration = polarity reversal,
    1 Hz = Exceeding the load time, 5 Hz = Overvoltage,
    all LEDs flashing = Overheating of power reduction.
    All LEDs duration = With battery connected to lower nominal voltage.

Charge curves

Charge curves

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Technical data

Device type G25–312–12 G25–324–6
Rated voltage DC 12 V 24 V
Nominal output current DC 12 A 6 A
Voltage first charge level 14,4 V 28,8 V
Voltage second charge level 13,8 V 27,6 V
Current limit approx. ± 2% Nominal output current DC
Characteristic IU, IUIa
Protection class II
Standards EN 55022, EN 61000, EN 60335
Reverse polarity electronically via relay
Back current at power failure ca. 1 mA
Input voltage AC, 50/60 Hz 230 V ± 15%
Input current at 230 V 1,45 A 1,4 A
Switching frequency approx. 40 kHz
Efficiency approx. 0,84 0,87
Ambient temperature range 0º C / +35º C
Ripple of the output current < 3%
Accuracy of the output voltage between 195-265 V < 0,5%
Load regulation * 2% 0,5%
Cooling Ventilation Convection
Weight approx. 1,2 kg
Dimensions (L x B x H) 175 x 140 x 84 mm (Höhe ohne Griff)

* measured at the cable end
Dial Engineering AG · Langfeldstrasse 96 · CH-8500 Frauenfeld · Tel. +41 52 723 0575 · Fax +41 52 723 0576 ·

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