I need to replace an original cables which are too short

If you're extending the circuit length, be very careful of voltage drop - not just a matter of supplying enough cranking current, but charging systems can misbehave if they see a modestly different voltage than what's actually across the battery. Without any other information, to be safe, I'd probably calculate the resistance of the original leads and try not to exceed that with the new ones .... which depending on how much longer they are might mean going up considerably in c.s.a. (not just one size).

Also consider faults - unless things are fused at the battery end (often not done, as you don't want arcs from fuses igniting evolved hydrogen) battery leads usually have to be reinforced (e.g. by a sheath as well as insulation).

   - Andy.

Or if they have to be 4 times longer you could I suppose you could use 4 in parallel to get back to the same resistance. suddenly its all a bit of a nightmare.

Are the batteries in parallel or series (24 V system) The latter will be less freaked by voltage drops.

PS whats it say after CSA on that cable ?

Mike.

Edit - Better if I read the original question. It is indeed 24V. In terms of Voltage drop, that  is something in your favour.

Or if they have to be 4 times longer you could I suppose you could use 4 in parallel to get back to the same resistance. suddenly its all a bit of a nightmare.

Are the batteries in parallel or series (24 V system) The latter will be less freaked by voltage drops.

PS whats it say after CSA on that cable ?

Mike.

Edit - Better if I read the original question. It is indeed 24V. In terms of Voltage drop, that  is something in your favour.