Thread: 160A alternator upgrade, will the cables cope?

nope the original cable was marginal at 100A if it was trying to charge a dead flat battery...

Id run heavier personally.

thanks, Its only for one standard battery so I'll probably just stick with the 100A.
I just saw a 200A direct swap alternator advertised LOL, maybe so you can do a bit of welding if needed

I've not been overly impressed with LR wiring/cables...(co$t) from experience of my RRC and another older Deefer.

If the bigger alternator is not much more expensive, I'd be inclined to look at it. - Reasoning being that a unit designed for 160 ~200A will be running at the lower end of its specs when doing the work of a 100A one. - Means less internal heat, means longer life, more money you don't have to spend. Again. Soon...

You can never have too much alternator capacity

Hi HangOver and as Dave posted, you will need MUCH thicker cable.

Minimum size would be 2B&S ( 32.15mm2 ) or 35mm2 and you need to replace the alternator to battery positive and all main negative cables, battery to chassis, block to chassis and anything else that has large cables, such as the starter motor, to get full benefit from the high output alternator.

Originally Posted by drivesafe

such as the starter motor, to get full benefit from the high output alternator.

Not quite sure how the starter motor can be benefit from a higher output alternator, unless you're not referring to the starter but to other power cables running from the starter motor terminal.

Originally Posted by Graeme

Not quite sure how the starter motor can be benefit from a higher output alternator, unless you're not referring to the starter but to other power cables running from the starter motor terminal.

The main benefit as I see it, is that the OEM cable to the starter is quite wimpy, so upgrading it will make life easier for the starter, reduce voltage drop and increase the life of the starter. And lets face it, beefing up ANY LR wiring is always a good idea...

I read somewhere once that some battery to starter cables are deliberately made a bit wimpy to provide a bit of resistance to protect the (wimpy) starter from very high current flows.....
Don't know how true that would be, I would be interested in hearing comments from those in the know?
Cheers,
Terry

Originally Posted by Graeme

Not quite sure how the starter motor can be benefit from a higher output alternator

Yep, the starter motor will not get one bit of benefit from the new alternator but as above, if you’re replacing heavy duty cables, you might as well do them all.

A heavier starter motor cable will still improve the starter motor because it will get a slight gain in the improved reduction in voltage drop between it and the battery.