Should you match +/- cable lengths for wiring from parallel battery bank to lynx distributor?

[Crocdundee]

Hello all,

I am in the final stages of planning for installing a victron setup in my RV. I am replacing my existing lead-acid batteries with lithium batteries (litime 24v @ 230ah). To keep it simple, do the positive and negative cable lengths from the battery bank to the lynx distributor need to be the same length (inclusive of fuse block and shunt)?

I've watched and read differing opinions on this (see list below) and still a bit confused. I've attached my battery layout below where I will be wiring two 230ah lithium batteries in parallel lengthwise. From my layout diagram, I understand the #1 cable set between batteries need be the same length but again, I was just unsure if the #2 cable set outgoing to the lynx distributor needs to be the same length.

A few references showing mains should be the same length
1) An Explorist.life wiring video
2) Voltage ripple as explained on Matts Van wiring video
3) Lauren van install wiring video

A few references showing matching main cable lengths are not required.
1) Wiring unlimited's battery bank wiring diagrams seem to show unequal cable lengths for diagonal wiring main lines
2) A few posts on victron forums (see example here)
3) Explorist.life wiring diagram (see here) seems to show wire lengths not being equal. I am trying to closely follow these plans.
4) "The main (+) and (-) wires do NOT need to be the same length." from Eggo on a similar post.


My battery layout.

 

[sunshine_eggo]

Hello all,

I am in the final stages of planning for installing a victron setup in my RV. I am replacing my existing lead-acid batteries with lithium batteries (litime 24v @ 230ah). To keep it simple, do the positive and negative cable lengths from the battery bank to the lynx distributor need to be the same length (inclusive of fuse block and shunt)?

I've watched and read differing opinions on this (see list below) and still a bit confused. I've attached my battery layout below where I will be wiring two 230ah lithium batteries in parallel lengthwise. From my layout diagram, I understand the #1 cable set between batteries need be the same length but again, I was just unsure if the #2 cable set outgoing to the lynx distributor needs to be the same length.

A few references showing mains should be the same length
1) An Explorist.life wiring video
2) Voltage ripple as explained on Matts Van wiring video
3) Lucy van install wiring video

Nope.

A few references showing matching main cable lengths are not required.
1) Wiring unlimited's battery bank wiring diagrams seem to show unequal cable lengths for diagonal wiring main lines

The above is the only definitive reference you have provided in your post (well, except for #4 ).

Total cable length doesn't matter. RESISTANCE does. Length is just the easiest way to get there when using one gauge.

You could even choose different gauges and lengths as long as the resistance is the same. For example, 5awg is about 2X the resistance of 2awg. So 2' of 5awg would be the same as 1' of 2awg.

If using the same gauge, you could have 1' of negative and 5' of positive on one and 2' of positive and 4' of negative on the other, and you're good... because both total 6'.

In MANY cases, making them all the same length is just easier to keep track of especially if you're ordering cables pre-made.

2) A few posts on victron forums (see example here)
3) Explorist.life wiring diagram (see here) seems to show wire lengths not being equal. I am trying to closely follow these plans.
4) "The main (+) and (-) wires do NOT need to be the same length." from Eggo on a similar post.


My battery layout.

Your battery layout is fine.

 

[Crocdundee]

Thanks for the confirmation Eggo, I greatly appreciate it. Happy rest of your holidays!