New Starting Bank 8V71Ti

[Boatsb]

All the battery cables should be 4/0. Jumpers included.

[oscarvan]

All the battery cables should be 4/0. Jumpers included.

What he said. NOT the place to skimp. Giving the starters all they need avoids a world of potential hurt.

[SKYCHENEY]

Out-rush and in-rush of current to and from the terminals with a starting load is to ALL terminals so the cables all need to be of equal size including the jumpers.

[Photolomy]

Now I’m curious. Suppose the starter pulls 100 amps at 32 volts. How many volts and amps are the jumper cables between each 8 volt battery carrying?

The 8 volt batteries are in series, thus the current is going out the last battery, through the starter and back into the first, out the first into the second and so on, and thus it is 100 amps throughout. In a parallel situation, the current is divided (or added depending on how you look at it).

[Boatsb]

No reason to use less than 4/0 . With length and age of some of the components you want all the copper you can get in the battery cables.

[Captain Ralph]

When batteries are in serial, voltage goes up, current the same.
In parallel, voltage stays the same, current goes up.

Current and/or voltage loss is the worst event in any configuration. Cables and connects must be at the best to avoid any losses.

Nothing is for free.