Hello Vito I think the boost button is intented to start up cares whose battery is nearly dead. I have one of these, and if you connect It to the battery and the battery still gives 11.5v, the jump starter will detect the battery and It will help you to start the car. What happen if the battery is too low that the jump starter cannot even detect the battery? this is why the boost button is there: you press It and It will provide current no matter if the battery is too low or even not detected. You said that this device cannot start a car with a battery almost discharged, but in my experience you can do it, in fact I strarted once my w201 with a 2.3 engine with even no battery at all using the boost button. Also I would like to mention that this device includes a polarity check protection, so if you made a mistake and connect possitive with negative the device will detect It and prevent any damage to the car or the device Itself. Something to take into account is as well that if the car has any problems starting, then do not try to crank it for more than 5 or 6 seconds or you might damage the jump starter. If your car is started but then it stalled, then do not try to crank it inmediately, wait some time until you try for a second time or you might damage the jump starter as well
Хорошая штучка!!!
Hello Vito
I think the boost button is intented to start up cares whose battery is nearly dead. I have one of these, and if you connect It to the battery and the battery still gives 11.5v, the jump starter will detect the battery and It will help you to start the car. What happen if the battery is too low that the jump starter cannot even detect the battery? this is why the boost button is there: you press It and It will provide current no matter if the battery is too low or even not detected. You said that this device cannot start a car with a battery almost discharged, but in my experience you can do it, in fact I strarted once my w201 with a 2.3 engine with even no battery at all using the boost button. Also I would like to mention that this device includes a polarity check protection, so if you made a mistake and connect possitive with negative the device will detect It and prevent any damage to the car or the device Itself. Something to take into account is as well that if the car has any problems starting, then do not try to crank it for more than 5 or 6 seconds or you might damage the jump starter. If your car is started but then it stalled, then do not try to crank it inmediately, wait some time until you try for a second time or you might damage the jump starter as well