# Deep cycle marine battery to start truck

**URL:** <https://boards.straightdope.com/t/deep-cycle-marine-battery-to-start-truck/140759>\
**Category:** Factual Questions\
**Created:** [December 5, 2002, 8:15pm UTC](https://boards.straightdope.com/t/deep-cycle-marine-battery-to-start-truck/140759 "2002-12-05T20:15:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![hammerbach](https://avatars.discourse-cdn.com/v4/letter/h/73ab20/32.png) [@hammerbach](https://boards.straightdope.com/u/hammerbach)\
**Post date:** [December 5, 2002, 8:15pm UTC](https://boards.straightdope.com/t/deep-cycle-marine-battery-to-start-truck/140759/1 "2002-12-05T20:15:17Z")

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My friend Jim has a marine/deep cycle battery in his truck and is using it in place of an automotive battery.  
I know why he can’t use the auto battery for deep cycle applications, but are there any ramifications to the other way 'round?

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**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\
**Post date:** [December 5, 2002, 8:29pm UTC](https://boards.straightdope.com/t/deep-cycle-marine-battery-to-start-truck/140759/2 "2002-12-05T20:29:01Z")

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Regular auto batteries are designed to provide maximum CCA for a given volume. This is achieved by maximizing the surface area of the electrodes, which necessitates the use of _many, thin_ plates. (This also decreases the battery’s source resistance, which is a good thing.) One disadvantage, however: Because the plates are so thin, they have a hard time withstanding deep discharges.

Deep cycle batteries are the opposite; they are designed to withstand multiple deep charges. This is accomplished by using thicker plates. This also means there are _fewer_ plates vs. the auto battery (for a given volume), and thus means there is less CAA and more internal resistance.

The upshot of all of this is that you’ll have less CCA / more internal resistance when using a deep cycle battery vs. an auto battery for a given volume. I would bet this is usually not a problem in warm weather, but problems may crop up when the temperature dips.