Tapping into a 12 volt bank from any of the positive terminals detrimental to the bank?

Paulaner

This is not so much a solar related question but I've read many of the answers in regards to battery banks and am really impressed by your answers. As I am a beginner, this probably sounds simple and a no brainer but, I can't find an answer to this question in the forums I've looked at. I just hooked up a bank of three 12v batteries in parallel for a car audio project. The alternator charging cable and electrical system power cable are connected to battery one as are the grounds. Batteries 2 and 3 are in parallel to one with no other connections. I know I can, but is it okay to tap into any point on the positive or negative lines? Or is it best to pull everything and ground everything from battery 1?

BB.

Welcome to the forum Paulaner,

Actually, it does matter... Lead Acid (and some other chemistries) have very low internal resistance. And if you connect the batteries "incorrectly", you will get some batteries receiving more charging current (closer to the +/- charging connections) and the batteries farther away (such as ladder connected batteries), will get less charging current (battery cable resistance reduces current flow to batteries batteries farther away)...

And similar for loads, the battery closest to the +/- load cables will supply more current than batteries farther away.

Here is a good website explination on how to connect batteries in parallel for optimum performance:

http://smartgauge.co.uk/batt_con.html

-Bill

Paulaner

Bill,

Thank you. From the bottom of my heart. Thank you. I've been working on a custom car audio project for some time now. You'd be surprised how many aspects there are to it. Electronics (oscilloscope testing of gains), wiring, soldering, woodworking, design and fabricating, fiberglassing, accoustics, sound deadening, enclosure calculating (interior volume, port area and length, air velocity, frequency tuning). So trying to find good information can be daunting especially if you're a novice like me. The link you gave me was a gold mine of information that I've been searching for. It makes so much sense too. All information that I've been finding on battery banks has been questionable or contradicting. Thanks you so much for taking the time to send that to me. Before asking my question, I was searching around the forum and reading a bunch of articles.You're in a lot of em with really good advice. Thanks again. Oh and I'm using AGM's not the FLA's. It's less messy. lol .

-Paulaner

BB.

You are very welcome Paulaner.

If you ever want to tell us about your custom car audio project, I am sure many of us here would enjoy reading the details.

Take care,
-Bill