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Every once in awhile we get a customer that comes in looking for a 16 volt battery.

The conversation goes something like:

Customer: "Do you guys have any 16V batteries?"
Me: "Why are you looking for a 16V?"
Customer: "I'm not sure I've just heard they are better, doesn't it give you better sonar imaging?"

For fish finders and live sonar, a 16V lithium battery is only truly advantageous over a 12V lithium battery when you're using smaller gauge wire, which is more susceptible to voltage drop.

Or due to the higher voltage, a 16V battery actually delivers more power (Watts) for a given amount of current (Amps) than a 12V system. This means that while the amp-hour rating may be the same, the 16V battery's watt-hour capacity is higher. Therefore, it will provide a longer run time for the same device, as the device will draw less current from the battery to achieve its required power.

As an example if you are running two Lowrance HDS Pro 12's and two Garmin EchoMap 12's with a black box, you would need a 12 volt lithium with a 130ah rating to run roughly 10 hours. In contrast, a 16V 100ah rating would also give a guy roughly 10 hours. 

Random side note, Tesla went with a 48V system in the Cybertruck and reduced the amount of copper wiring by 70% versus going with a 12V system.

In some cases where you need more energy packed in a certain size battery this can be advantageous but now that we have larger capacity 12V lithium's in a smaller form factor  it really seems the 16V battery is nothing more than a marketing ploy. We don't recommend buying into it for the most part. There are situations where a 16 volt might be the way to go, but they are few and far between.

To put it simply, the fish finders only care that they are receiving 12 volts. If your power wires going to the fish finder are insufficient, voltage drop occurs, and in turn you might have 12 volts at the battery but only 11.5 volts at the fish finder... this is when you run into poor sonar performance.

If you're using the correct wire gauge to power your setup, the benefits of 16V become far less significant.

Understanding Voltage Drop and Wire Gauge

Voltage drop is the loss of electrical pressure that happens as electricity travels through a wire. The longer the wire and the thinner its gauge, the greater the voltage drop. This drop is a serious problem for marine electronics because they require a steady voltage to operate correctly. A drop in voltage can cause your fish finder to reboot, display a blurry image, or even shut down completely.

Thicker wires have a lower resistance and can carry more current with less voltage loss over a given distance. Most manufacturers recommend a specific wire gauge for a given length of wire to ensure your fish finder receives a consistent and sufficient amount of power.

I'll try to post soon how we calculate wire gauge size based on the fish finders and electronics for customer rigged boats here in our shop...

But

You can read more about voltage drop in our post here.

16V vs. 12V Lithium and Voltage Drop

Here's where the difference between 12V and 16V batteries becomes clear. A 12V system starts with a lower voltage. If you have a long run of small-gauge wire, the voltage drop can easily cause the voltage at the fish finder to fall below its operational threshold (e.g., 10V). This is a common issue with DIY installs that use inadequate wiring.

There are still a lot of boat manufacturers out there that come right from the factory, even today, with inadequate wiring for a lot of the high powered fish finders on the market.

A 16V system, however, starts with a higher voltage. This provides a greater **voltage "buffer"** to combat the same voltage drop. Even with a significant loss over a long, thin wire, the voltage arriving at the fish finder may still be high enough to keep the unit running without issue. Think of it like starting a race with a head start. The 16V battery has more voltage to "lose" and still finish above the minimum required for the electronics. 

The Bottom Line

For most boaters, if you've wired your boat correctly with the appropriate gauge wire, you will not see a difference in performance between a 12V and a 16V lithium battery. A well-designed 12V lithium system will provide more than enough stable power for your electronics, giving you a clear, crisp image without the need for a specialized 16V system.

The primary benefit of a 16V battery is its ability to overcome the problems caused by a less-than-ideal wiring setup, essentially acting as a band-aid for poor wiring.. or in certain situations where extended run times need to be available that a 12v system doesn't have the capacity for.