Can I Use Car Battery In Boat Motors When Needed?


Okay, so this is a very fundamental question, given the economy, people and communities face nowadays. We all need some sort of replacement or alternative to products that we normally rely upon (and so give them wear and tear). That said, could I or can I use a car battery in boat motors as a replacement for marine batteries? Well, before that question can be answered, it can help a lot to clarify a good margin of difference between what we know as marine batteries (or boat batteries) and car batteries.

As a toss-up situation, both car batteries and marine batteries have a shared connection with each other and similarities are good enough (probably why a question like this gets asked a lot). And, because this question gets thrown out a lot in public domains or in hearsay, people usually respond the advice that it is probably a lot better to use a marine battery for a boat (because it is designed for those) and to use a car battery for a—you guessed it—car! (because it is designed for those, too).

So, it may sound tongue in cheek and quite sarcastic, but the question has had some people wonder why a possible swap would be advisable. This is understandable. But, again, let us explore this possibility.

So, marine batteries or boat batteries are unique in that it is usually labeled as dual-purpose types. So, in essence, they have what is called starter motors and trolling motors. These starter motors need a ‘cranking’ type of battery in order to properly start the engine.

These trolling motors need a ‘deep cycle’ type of battery in order to properly propel the vehicle through a body of water, whether it is small bodies like rivers and lakes or big bodies like oceans. Some manufacturers sell a dominant type on either end of ‘the cranking’ or ‘deep cycle’ spectrum. But, dual-purpose types are a standard for many of these boat or marine batteries.

This is mostly due to the unique environment and challenges presented by living a marine life. Whether a marine biologist or a recreational angler, this standard operating procedure applies.

The batteries used to power the engines of cars are surprisingly one toned (or one note). The battery in cars is primarily those that are labeled as “cranking’ types, which are just used in order to bring the engine to a start. Other than that, they have little use soon after the engine has begun to roll around into a running momentum.

The momentum from the engine (which is running already) powers the rest of the systems and can already recharge the battery that it took to start it, by the same token. Nifty and reasonable, but quite different in usage compared to those of boat or marine batteries.

Marine batteries not only need to have a concern in starting up the motor engines but also has to have the concern for a gradual or consistent flow of energy distributed throughout the trip.

Another difference with regards to these batteries is in the overall design. Most anglers (fishing enthusiasts) know that between a car battery and marine battery, the latter usually holds more weight in them. Of course, these all differ depending on the manufacturers.

But, in general, marine batteries are heavier. A key factor in this is that the marine battery usually has a thicker case plating in order to protect it for a long and water bound trip. The batteries that are used to power cars usually have thin plates. This all depends on the contexts of the environment they are designed and marketed for.

Consensus on Motors of Boats and Cars

Again, given some of the key differences between marine batteries and car batteries, it probably comes as no surprise to anyone that marine batteries are quite appropriate for the vehicle they were designed for. Still, it does not mean some flexibility cannot be given when one really needs to consider the possibility of a car battery powering up a bass boat or a large fishing boat. That said, some limits need to be observed with regards to this.

In practice, applying the design of the car battery as a boat battery will work as a ‘cranking’ starter type. Most certainly, some products or manufacturers have been very keen on capitalizing on this very observation. After all, if a car battery is primarily used in order to start up an engine, it can certainly be used to start up or ‘crank’ up a marine motor (the starting motion).

This is evident by the amount of CCA (cold crank amp) rating offered by many car batteries. They evidently share the same CCA rating for they have the same purpose in this aspect of engine control.

That said, it does not follow that a car battery will sustain power within a marine vehicle even with a 1,150 CCA rating (one of the highest ever offered in the given mainstream market). Cool as such a process is (cranking it up with a large jolt), it is mostly theoretical and not so much evidence that is supported by empirical research and through trials.

So, for the meantime and space, it is not so much a good option for many people to begin investing in the best car battery with a high CCA rating because, as consensus stands, it just is not a good transfer outside of the starting crank one can get initially. It can become a very dangerous procedure when taken to its limits in terms of battery design (given the many car batteries and marine batteries available).

To review, for the most part, could I or can I use a car battery in boat motors when not in the presence of a marine battery? It seems, in design and function, only in the process of starting up the motor engine. Yes, this goes for the highest CCA rating model you can find. It cannot be ignored that you need a downregulating ‘deep cycle’ type battery for the later part of propelling across waters.