By Kelechi Deca
This is a lesson I learnt the hard way that almost made me regret helping out a brother because it took me almost half day of driving and stalling to get the car program reset again.
For some cars, you must leave the key inside the ignition while removing the battery cable. If not, your day would be messed up.
If you drive a BMW, you should have been warned about tampering with the battery because it can demobilise the car totally. BMWs have a very unique battery system where every car has its own battery thus replacements follows a process for matching battery.
But for others disconnecting a battery may cause a rough or unstable idle; it also could cause stalling because the idle speed is abnormally low. In other cases, disconnecting a battery affects transmission functions, causing symptoms such as late and/or harsh shifts.
The trick I found out is using the headlamp to drain power in the computer system so you won’t have residual power that would interfere with the programming when you reconnect.
Because car systems are different, but majority work with same formats so before you start, remove the negative first, wait a little, then switch on the headlamps even though they won’t come up, what they’ll do is drain residual power in the system. Then remove the positive.
After installation, start it and leave it on neutral for about 10 minutes. Some cars will stall and go off. Start again on neutral. After a little stabilization, drive on low gear like 2 for about 15 minutes and watch for stabilisation.
In some cars, switching on the AC can help with added load on slow drive before stabilisation. This can take most of your time unless handled professionally.
