8D Marine Battery - 12V Deep Cycle, 240 Ah

These 12 volt 8D batteries are available in either deep cycle or starting versions. This is the deep cycle model.
Dyno Battery takes pride in over-building the internal components of their batteries so they last longer and can withstand the stresses imposed by less-than-perfect care.
Dyno batteries weigh more than competitive lead-acid batteries of the same group size because they contain more lead — for higher capacity and longer service life.

• Priced lower, pound for pound, than other batteries of identical size and shape
• Includes rope handles at each end
• SAE automotive style post terminals
• Overall dimensions (including terminals): 20-3/4"L x 11"W x 9-3/4"H
• Made in Seattle Washington, USA


Heavy on the technical side...

Starting Batteries vs. Deep Cycle Batteries
• Starting batteries need to produce a lot of current very fast. They have a high number of thin plates creating a large total surface area through which electric current can be released.
This structure makes them ideal for producing large bursts of current for a short period - just what an engine starting motor requires, but the relatively thin plates hold less total energy, and are not robust enough to withstand repeated deep discharges without physical damage - such as warping which can produce internal short cicuits.
For a long service life, starting batteries are meant to be discharged, and then immediately recharged.

• Deep cycle batteries, on the other hand, are ideal for extended low current draws, with longer periods of time between charges.
They typically have fewer plates which are thicker and more robust.
Although this may result in less total surface area exposed to the electrolyte - so peak current output is lower - with thicker plates, their total energy content is higher, and their heavy-duty construction allows deep cycle batteries to withstand deep discharges with less physical damage.

You may have noticed in the Specification Tables that, counterintuitively, the starting model of these 8D batteries has a higher measured Amp-Hour capacity than the deep cycle model.
This has been attributed to the higher porosity of the lead oxide used in the starting version, allowing for faster acid diffusion within the plates.
Amp-hour capacity and number of plates per cell not withstanding, the deep cycle version of these 8D batteries are purpose-built for deep cycling.
They have thicker plates, heavier support grids, thicker insulating separators, and more total lead.

Do not use the 8DC Starting Battery in deep cycle applications, thinking you will get more amp-hours out of it on a regular basis — it is not built to withstand the physical demands of deep cycling.
Use the heavy-built 8DD Deep Cycle Battery for cycling applications.