Batteries

We installed 6 of those big square Odyssey batts for a customer. Had custom mounts and shelf tops made with fiddles.
Owner stores all kinds of stuff in big Rubbermaid bins and tied down the these shelf tops. One bank went to both bow & stern thruster.
6 years later, before purchase survey, we load tested these big orange monsters. Pegged my carbon-pile load tester (500 + Amp) till the temp warnings came on.
Chargers recovered the batteries before I could load all the stuff (junk), back on the cover shelves and back out of the E R.

I was really impressed.

This customer had a near in da wind check book. The Batts, custom mounting system and more cost a bit but he was happy. New owner one year later is still happy also.

I still make sure my customers understand the differences between flooded, AGM and the AGM/Gell combinations that are available.
Maintenance free (zero maintenance)is usually the first topic that comes up. And that's what they get, either the East Penn or LifeLine AGM batteries are installed.

Personally (the cobbler), My ships combinations of 8 (19") & 12 volt batteries ( 12, 24 & 32Vdc systems), on my budget limits me with flooded batteries.
I'm in my ER checking strainers, batteries, sumps, condensate drains, yada, yada every 6 months. I am blessed with fair access to them all.
Batteries just a bit down but not down or fried, then topped off.


The moral is; I've seem them all (Different brands of flooded, AGM, Gel, Sprial) last long times, and not last at all. Dock queens to boats that go to work every day.
Skippy Js comment above; It all depends on access; is probably the best first question that should be asked when deciding between flooded or not, then budget.

When making parallel banks, the positive load/charge lead is at one end of the bank, the negative load/charge lead is on the far battery.
Resistance of the batteries, cables and connects are then neutralized (lack of a better word) and all cells get the best balanced charge.

Yes, Method 2 is what I was referring to.
Method 3 & 4 may be fine for more than 2 or 3 Batts in a common bank.
IMO, method 3 & 4 require to much cable and waste of materials. Subject to more connects per battery post / more resistance per post.
Follow the book if you insist, KISS will always be our plan (method 2).
Thank you for your additional thoughts.