Install batteries into the SD Connect C4 multiplexer.

Mercedes SD Connect C4. Install the batteries.

When installing batteries follow the correct polarity according to the image:


It is recommended to operate the multiplexer SD Connect C4 with established internal batteries. Size AA Ni-Cd 1.2 V. the recommended capacity of 2400 — 2800 mA/h.

The need for internal batteries is caused by:

  • firstly that the multiplexer SD Connect which was fully independent of the computer, running the Linux operating system, “gross” power-off that occurs when unpulling the diagnostic cable from the vehicle and then loading up the device when you reconnect to the car it is not advisable, and in some cases, may lead to breakage of the multiplexer
  • second, in the absence of internal batteries, at the time of engine start in a vehicle voltage of the vehicle, and hence in the power supply circuit of the multiplexer appearsudden voltage power supply that can cause loss of connection between the multiplexer and PC, and in some cases, may lead to breakage of the multiplexer

The presence in the SD Connect battery allows you to keep it in working condition as if disconnected from the vehicle at the time of the sagging of the supply voltage and eliminates the need to re-download the next time you connect to the diagnostic connector.

In mode, the power only from internal battery (disconnected from the diagnostic connector), it is possible to switch the multiplexer into “sleep mode”, which is not possible with power from the car. A complete shutdown of the device is not provided. It possible by  taking out the batteries or changing the power diagram (see video).

Without changes in power diagram, long-term, without the use, storage multiplexer, batteries should be removed, as in sleep mode, the standby quiescent current is 10-60 mA with periodic jumps up to 190 mA. With the recommended battery capacity is 2400 mA/h, and provided that they are 100% pre-charge ensure retention sleep mode in only 3 to 7 days. Further, the voltage of the battery falls below critical, which negatively affects their service life.

Before removing the batteries, switch the multiplexer in STANDBY/SHUT DOWN. At the time of connection to the vehicle connector, the instrument automatically exits sleep mode and begins charging the internal batteries.

Capacity of used batteries in multiplexer Mercedes SDConnect C4 must be at least 2000 mAh.

The message on the display “insert the battery” or “check battery” may indicate a capacity loss of one or more batteries or a bad contact in the circuit of the batteries. The increase in the total internal resistance of the battery module by more than 1 Ohm is causing the message about not working properly or the lack of batteries.