Dear friends:

My battery charger has a 100 Ampere jump start feature. In the past, whenever I wanted to jump-start my gasoline cars using this capability of my battery charger, I just connected the + and -
cables from the battery charger to the discharged battery's electrodes WITHOUT disconnecting the battery cables from the battery's electrodes. However, Haynes manual for 240D says that I have to completely remove the battery cables from the battery's electrodes first and then connect the cables from a battery charger to the battery cables in order to jump-start a car using a battery charger. Otherwise, it will cause damage to a car's electrical system.

So which is the best and safest way to jump-start a car using a battery charger's jump-start capability?

For a diesel car with glow plugs (e.g. a 240D), will jump-starting a car using a battery charger (with 100 A jump-start capability) cause damage to the glow plugs' inner heating elements?

Thanks in advance for your help.

Eric