This really is not much more than a 12V lorry battery, albeit a rather heavy and in the UK at least a very pricey one.
There will be a massive starting current for some seconds, maybe tens or so, while the engine is being cranked by the starter, and then it will sit idle, charged by more or less normal 12V alternator spun by a belt from the engine, not much different to a traditional car.

Cable selection will be decided by the area of copper needed, and the environment  - heat. oil, fuel etc. And then finer stranded cable is used compared to normal fixed wiring, to resist vibration.

The wire nos you mention cover a range of high temperature soft rubber covered (EDPM) cables . 'AWM 'just means Appliance wiring material and really does not say a lot - almost all 'wire' could be AWM unless it is specially something else.

There may be an AWG code on there, but if not depending on the engine size, which is a proxy for starting current  we can probably assume we need the AWG equivalent of 25-35mm2  (AWG 4,2 or 1)

Or measure the OD of the old cable and compare with the table here.

https://www.interstatewire.com/ul-awm-style-3340-and-3374-config.html

So - why has the original cable failed ? (heat ? perished rubber? abrasion? )
This is what needs to be guarded against, and it may be that like-for-like repair is not the brightest decision, if it fails again in the same way, and/or  that some sort of re-routing or mechanical protection is needed.

If you can get a bit more detail about the cable and what has happened to it, we can point you at something suitable, that more helpfully will be readily available in the UK.

The number you give for the alternator

https://www.raad-eng.com/techdata/stamford/PI734D.pdf

Tells us it is a 1,6 MVA unit at 50Hz, when spun synchonously, but not the engine size, so while we can guess a cranking current, it is a guess.

Sanity check - battery is one of these ?

Mike

This really is not much more than a 12V lorry battery, albeit a rather heavy and in the UK at least a very pricey one.
There will be a massive starting current for some seconds, maybe tens or so, while the engine is being cranked by the starter, and then it will sit idle, charged by more or less normal 12V alternator spun by a belt from the engine, not much different to a traditional car.

Cable selection will be decided by the area of copper needed, and the environment  - heat. oil, fuel etc. And then finer stranded cable is used compared to normal fixed wiring, to resist vibration.

The wire nos you mention cover a range of high temperature soft rubber covered (EDPM) cables . 'AWM 'just means Appliance wiring material and really does not say a lot - almost all 'wire' could be AWM unless it is specially something else.

There may be an AWG code on there, but if not depending on the engine size, which is a proxy for starting current  we can probably assume we need the AWG equivalent of 25-35mm2  (AWG 4,2 or 1)

Or measure the OD of the old cable and compare with the table here.

https://www.interstatewire.com/ul-awm-style-3340-and-3374-config.html

So - why has the original cable failed ? (heat ? perished rubber? abrasion? )
This is what needs to be guarded against, and it may be that like-for-like repair is not the brightest decision, if it fails again in the same way, and/or  that some sort of re-routing or mechanical protection is needed.

If you can get a bit more detail about the cable and what has happened to it, we can point you at something suitable, that more helpfully will be readily available in the UK.

The number you give for the alternator

https://www.raad-eng.com/techdata/stamford/PI734D.pdf

Tells us it is a 1,6 MVA unit at 50Hz, when spun synchonously, but not the engine size, so while we can guess a cranking current, it is a guess.

Sanity check - battery is one of these ?

Mike