Booster pack unable to reach grounded bodywork

[firemunki]

I need to jump-start my van (2.5tdi VW T5) with a jump pack. However, the leads are pretty short which means I can't get the earth clip to a suitable unpainted bit of the bodywork.

On a scale of 1 to 10, how bad is it to use the negative terminal of the battery instead of the bodywork?

I will look at getting a mechanic to add something I can clip to for grounding in the future.

[kambites]

I'd say about 1. Ultimately the battery negative terminal is shorted to the chassis with a massive great conductive strap.

[Scrump]

1 out of ten.
If you are still worried then add a standard jump lead to the end of the jump pack lead.

[GreenV8S]

The main reason for wanting an earth remote from the battery is so that when you connect the earth last and disconnect first (you ARE doing that, right?) the spark happens away from the battery and associated explosive gases.

Having said that, people have got away with clipping leads directly to the battery and drawing an arc to the battery terminal for years and if you're in a well ventilated space and not doing anything to cause the battery to out-gas then it really isn't going to matter one way or the other.

[vikingaero]

The latest Lithium hand sized jump start packs all have leads about a 20cm long at the most. You simply connect them to the positive and negative poles on the dead battery rather than an earthing point on the engine bay. The earthing point is the preferred solution if it will reach.

[DirktheDaring]

On my T6 there was an Earth point at the headlamp bracket, I sanded the area a bit around the bolt.

Should look like this, assume the T5 is the same