Battery Wiring Shortest Cables

Hi All,

New Here. New to posting on forums. New to Off Grid.

Forgive me if this has been previously discussed. If someone wants to direct me somewhere else, feel free. But I have looked throughout this site and the google-machine and found some details lacking (and/or my understanding is lacking), so I thought I'd try a new thread:

I have a 12v system that's aging and tired so I purchased new batteries and am ready to install. Currently, the system is running (4) L16-style batteries in series and parallel, so 12v and 2x the aH. I am replacing with (6) L16-style for 12v and 3x aH.

The battery cabinet has space limitations so I need to run all batteries side-by-side. I found a diagram of possible wiring on this site, but wondered if one could use shorter cables (cost savings and good practice for energy flow) and spin some batteries to achieve the same thing. Probably best shown by example (below):

Example 1, found on this site (thank you for posting), shows all batteries side by side and polarity all lining-up. Example 2 shows my new batteries sitting on the garage floor awaiting installation. I marked-up the series connections (green lines / green '12 S') to achieve 12v and the parallel connections (red and black lines / yellow 'P') to triple aH, as well as negative and positive on the way to inverter.

Does anyone see any issue with this? It seems like I can use short cables for both series and parallel connections. In the 1st example the parallel connections would require longer cables. Anyting I am missing? Is there a problem sharing a post/terminal between series and parallel connections?

Any help would be appreciated. If my wiring would work, is there any reason I should line up polarity anyway?

Thanks

 

I think this is what you need.

Oh, my apologies.

to the forums!

 

That should work.

 

Paul, thanks for the link - a good resource. I will read carefully.

Out in the Woods - Thanks!

I sketched so many combinations trying to achieve the right combo that will fit AND use the shortest cable segments, but could find no similar wiring as an example. Good to hear from someone that I won't fry new batteries or inverter.

Thanks guys!

 

The most important thing here is, that your batteries charge as evenly as possible. Have a look at Method #4 (in the link I provided), before you decide on anything definite.

 

Paul, After 1st read, I can see there is some nuance to battery wiring. I will need to ponder (and re-read a few times). Thanks again.

 

Bruce in Alaska,
Thanks. We don't have high demands: a few LED bulbs at night and a computer or 2 during the day (and I'm looking into using them off DC instead of from the inverter). Chest Freezer draws the most. I appreciate your advice - I had heard not to draw them down below 50%, but when I saw the literature that came with the new batteries (battery cycle life when discharged to 50%, 70%, 80%, etc) I could really see how much shorter their life would be if used hard and not recharged. During summers we should have no trouble minimizing the DoD, but during winter I will need to run our 10kw frequently to get as much lifespan as possible.

How do you monitor the Depth of Discharge? Battery monitor? Other means?Our system came with a Tri-Metric (?) but I need to chase down the owner's manual, and I think I'll need to reset to account for the larger battery bank than currently in service.

 

2/0 for series and parallel connections and ground to inverter. 4/0 to inverter through fuse. Sound like enough? Inverter is 2500w Trace (U2512SB).

 

Loads of usage for the 12Vdc please !! Cuz I'll doo MATH

 

Hi there, Your top battery is not being utilized

 

The Ballance is so far off , Just let them burn up a set of GC units & then after they rebuy a year later, then they might understand .. & @12 Vdc , lost in the fog.
Sloth

 

@CrazyJs, did ya get your issues sorted?