Battery Wire Gauge?

[fam5mel]

With my recent dead battery and jack error issues I've decided to add a second lead acid battery. Also, with members advice I have ordered a Victron Smart Shunt battery monitor. Always great advice on this forum. What gauge wire should I use to parallel my batteries?

[Redapple63]

With my recent dead battery and jack error issues I've decided to add a second lead acid battery. Also, with members advice I have ordered a Victron Smart Shunt battery monitor. Always great advice on this forum. What gauge wire should I use to parallel my batteries?

Howdy,

Typical for fla is 6ga between batteries.

Bill

[powerscol]

With my recent dead battery and jack error issues I've decided to add a second lead acid battery. Also, with members advice I have ordered a Victron Smart Shunt battery monitor. Always great advice on this forum. What gauge wire should I use to parallel my batteries?

It all depends on the load and how far away your battery is. This article might help https://www.bluesea.com/support/arti...r_a_DC_Circuit

For my 4-6V in a series/parallel set up I have 2/0 for the series connection and 4/0 from each pair to the power in center. My inverter can pull 400A (200A per battery set)

So using the chart 200A requires 2/0. 6 awg will work for the typical 30/50A DC trailer service - check you max breaker on you trailer positive buss bar (usually where the battery cable attaches) and size accordingly for the distance.

Note for a DC circuit the power flows from and to the battery so the distance is doubled based on the wire run. So if the distance from the positive battery terminal and the lead to where it connects to the trailer power in bar is 5', the distance you use on the chart is 10'. I always use the 3% critical number, and usually size up to be sure I don't let the magic smoke out.