What good is it, if after a battery breakdown, you simply charge it again and then carry on as before. No, you should always try to find the reason for the failure. In the simplest case, it may have been an operational error, e.g., The lights were left switched on. The battery itself may also be defective and must be replaced. However, what if this is not the problem?
Your search and analysis must now include the entire electrical system. In this case, it is not only about the failure of components, but also about (silent) consumers, to which normally, one does not give any consideration. In addition, the operating conditions must be clarified. It's quite possible that the vehicle is always only briefly used. If then the electrical equipment has to work a great deal, there is, of course, not much chance for it to recoup the spent energy.
This is exactly the information, e.g., about the 're-starting ability' that the Electronic Energy Management gathers, allowing it to introduce the correct measures. Should an EEM be available, the suitable knowledge can be called up.
How does the EEM perform? The most important part is the battery sensor (see above figure) which, in regular intervals, registers exactly, the tension, current strength and the temperature in the vicinity of the battery. Unlike other sensors, which transmit the data to a control device, here a controller, which houses most of the Eem functions, is intergrated into the battery sensor. It is intergrated into networks through the LIN-Bus.
Tension, current (through Shunt) and temperature are constantly measured and stored, also during the dormant phases of the battery. Thereby, not only is the remaining charge known, but also, from the experience values of previous engine starts, also the demands on the battery. Present values and also much earlier values can be compared with each other. An understanding about the ageing and possible remaining lifespan of the battery is now possible.
Now, one could assume, that this system serves, primarily, as a warning, e.g., in the evening, when leaving the vehicle, that in the morning it will probably not start. No, this type of system must begin earlier. Thus, it can switch off functions which are not absolutely necessary, e.g., the second stage of the rear window- or the windscreen heating if the battery comes anywhere near the critical state.
Also the ageing degree ascertained by the EEM is not used only as a warning, but is included in the question of the restarting ability. This means, that with a relatively healthy battery, the system can allow it to get closer to the critical limit without switching off any functions, with an older battery, it must react earlier.
Instead of consumption, it can however, also take care of the production of energy. Just imagine, a cry of help goes out to the voltage regulator of the generator, which then switches over, from fuel saving to high charging, and during idling, requests a particular engine RPM from the engine control device.
For the workshop, these are more complicated and hardly manageable contexts. In this case however, the small micro-processor on the battery terminal also helps, because it makes the error storage possible, and by the way, can also register parts of the on-board network. This way, a control device which does not go to sleep after the predetermined time, can be recognised by its too high power consumption.
It still goes further. Depending on the resulting temperature, even the determination of the cold test current is possible. Batteries mounted at various distances from the generator can also be supplied with accordingly differing charging voltage. Basically, the complete charging behaviour of the generator is recorded. Of course the threshold to the gassing voltage can be much better recognised.
The other way round, if the battery, through a too low charging voltage, is not sufficienly charged, its possible capacity not exploited, which is the case with a permanently overtaxed battery, would have its lifespan shortened. Here the EEM can also help.