Rev cut also not so dulan. To be exact, the limiter is a FUEL CUT! No use, it's rechargeable battery, as and when your car battery kong, the rechargeable battery is supplying the same amount of voltage as your car battery. HOWEVER, the possibilities are, when your fren's battery kong and you refuse to let him/her jump start with your car. YES! You can use your backup battery and put over his/her car to start first and put it back in your car continue charging.
i mean like charge the battery den leave it in the car without any connection. in case my car batery breakdown. nak pg dekat itu kedai batery just use the jumper cable and start lepas tuh pg kedai tukar batery baru. and btw i ade problem dah 3 kali jadi. sometimes my car wont start. the cranking is there. then i need to cabut the batery to reset baru boleh start blek.