Two stacked 12V batteries

[Brookhaven Rob]

I have read threads in the past about adding an additional battery to my 2011 Sierra bunk house. I understanding the wiring, i'm keeping the same voltage, just adding capacity. the main questions is how are your batteries mounted? I would prefer to have them in a custom made "tower", have them stacked for better usage of the space. does anyone have any pics? I will not be adding an inverter at this time, just a simple battery addition. would an isolator be required?

thank you

[Aussieguy]

depend on where you storing them and what type they are

heavy lead acid OUTSIDE each in a good support platfrom.box

Inside storage AGM same... they need good flat storage if one breaks they can still make a mess.
Glass mat still uses acid with fiberglass matting material to act as a wick/baffle acid will ooze out if damaged.



Lithium
they claim they can be stored in any position ... you could lay them on their sides and stack them ...
BUT.... if you also use that same compartment for storage
you have to protect the wiring (on the side) from items hitting/shorting the terminals

I put mine .. side by side traditional way in the pass through under the bed, for ease of maintenance and IF I ever buy a Inverter later, it can be mount attached to the wall BUT above the batteries.

[TacomaJoe]

On the electric side, you want to have batteries of the same chemistry, age and capacity. No isolator needed. For best balance of the two, keep your current negative cable on the bottom battery and move the positives to the added battery (diagonal connection). You're not changing loads, so no wire change needed.

On the physical side, the box design would need access and ventilation to each battery. Stacked you would need enough strength to counter tipping when braking. I had added one to my trailer next to the original on the tongue in its own box. Later I changed to one big box that had room for both plus some other additions.