Solar panel to double battery

[ScottBrownstein]

From a purist point of view, the batteries are also paralleled incorrectly. It looks like the chassis negative and positive both come from one battery and the second is merely parallelled. Actually the chassis positive should be on one battery and the chassis negative should be on the other! At low current it shouldn't be a problem, but ideally I would move the negative over as well as the solar controller negative.

Easy to do but probably both unnecessary.

[Flybob]

This discussion pops up on the forum every few months and is usually debated extensively. For large battery banks with high current demand one way has an advantage over the other, but for small banks (2 batteries) and average RV current demand the difference is so slight it doesn't really matter.

[HappyCamperCanada]

So what I'm hearing is that the differences are negligible considering the current demand involved so if I just leave it as is, it's fine. It's not going to improve dry camping battery life drastically by switching it around.

[SlowrideHD]

Originally Posted by HappyCamperCanada

So what I'm hearing is that the differences are negligible considering the current demand involved so if I just leave it as is, it's fine. It's not going to improve dry camping battery life drastically by switching it around.

It will work correctly as it is wired. On these forums, lots of folks will debate the minutia of details :-) When batteries are wired in parallel only, there is an advantage when having power and ground connections at opposite ends of the battery bank, although it is very slight. Many of us like to tinker and even a very slight difference is worth a good deal of trouble, if nothing else....just to say "this is the best way to do it"!
Suit yourself, with a two battery parallel bank, I doubt you would ever notice a discernable difference in performance. More importantly, familiarize yourself with capacity of your bank and at what level are healthy for your batteries. For instance...12.1 volts is the lowest you ever want to deplete a lead acid volt level to....this equates to 50% of your power and is the low limit before irreversible damage will begin to limit the life of your batteries.

[SS Cruiser]

there's a right way and a wrong way. Why would anybody do it the wrong way when the right way is same amount of effort? I would argue that a small amount of imbalance is even more of an issue on a small system as oppose to a large system because the small system is limited in its output.

[clr]

Yes your wiring diagram is the best way to connect the two batteries. This configuration ensures that both batteries are being used as equally as possible. Others are correct that all connections to one battery are electrically equivalent, but that is only true if the connections to the other battery are very good with no poor connections. If you account for the slight possibility of the paralleling cables not being 0 ohms, then your connection is better since it forces the current to flow through both batteries equally.