Bowfishing Lighting Series, Part 1: AC vs. DC

First and foremost, safety is of upmost importance when installing an electrical system that will be used anywhere near water. Whether AC or DC, an incorrectly installed system can be just as dangerous as using a hair dryer in a bathtub and can lead to injury and death. Though, it can be said that both are fundamentally safe if installed correctly.

Choosing the right system depends on your goals as an archer-angler and, as with most things, how much you are willing to spend. But don’t be discouraged! You can build a system that will work just fine without spending a fortune. Now, let’s talk about what you should know before choosing a lighting setup for your bowfishing needs.

System Sizing

Before you spend any money on lighting equipment, you should start by figuring out your system size needs. Proper system sizing will ensure your boat has enough charge so that your lights can last an entire outing. Depending on how often you’ll be bowfishing, this could be a few hours or an entire night.

The first step is to determine what the total current draw will be for your lighting system. To do this, you need to count how many lights will be on your boat and then calculate the current draw for each light. Lights are specified in watts; to convert to current draw, divide the watts by the voltage they utilize.

Here’s an example: A 120W light that runs on 12V would draw 10 Amps of current.

So if you’re using ten identical lights on a boat, the total draw would be 100 Amps.

10A x 10 lights = 100A

One final note about system sizing, don’t forget to take into account the current draw of your trolling motor. This can be quite tricky, so we’ll cover that in a future article.

Next, you’ll need to choose whether your system will be DC or AC.

DC Systems: Quiet and Economical with Limited Run Time

DC Systems have the advantage of stored power in the form of batteries and can either run with a small generator or none at all for shorter outings. DC systems are silent when the generator is not running. They are generally cheaper to set up than an equivalent 120V AC system. The drawbacks are they tend to be heavier and have less total run time.

Deciding whether to implement a 12V or 24V DC system comes down to personal preference. Total runtime of cheap batteries is highly dependent on the current discharge rate. Lower operating current of a 24V system may lead to longer run time compared to a 12V system. When utilizing a 12V system, this effect can be mitigated by choosing deep cycle marine batteries that can handle the higher current draw.

If you decide to choose a DC setup, we recommend matching your lights to your trolling motor to minimize the number of batteries you need. Purchasing lights that run on the same voltage will likely result in weight and efficiency savings. For example, if you have a trolling motor that runs on 12V then implement 12V lights, and if your trolling motor runs on 24V then implement 24V lights.

To determine how many batteries to purchase, you need to calculate how many Amp-Hours you will need for a typical night outing. Batteries are specified in Amp-Hours; take the number of hours you’ll spend on your boat and multiply by the total current draw of your system.

For example, if I spend four hours on my boat and my lights and trolling motor draw 100Amps on average, then I will need a 400 Amp-Hour system (4 hours multiplied by 100 Amps). Next, determine how many batteries are needed by dividing the required amp-hours by the amp-hour rating of the chosen battery.

There comes a point where the number of batteries needed to power a system is no longer practical. For example, if I plan to spend twelve hours on the water with a 100 Amp current draw, then I will need 1200 Amp-Hours. This means I would need twelve 100Amp-Hour batteries to power my system for 12 hours. This is definitely not practical because of the size and weight of the batteries! In these cases, it makes sense to add a generator to recharge your batteries or utilize AC lights.

Loxley Pro Tip: If you are only going to spend 4 hours on the water on your longest outings, then a system to that has the ability to last 12 hours is overkill.

AC Systems – Light Weight and Longer Runtime with Additional Cost

AC systems have the advantage of being lightweight compared to battery-laden DC systems, and they free up cargo space that would otherwise be taken up by DC batteries. This is a huge advantage when you’re on a smaller boat that may be heavy with tons of fish.

Without a stored power source, a larger generator is required to power the same amount of lights. You’ll never have to worry about running out of charge, but you will have to run the generator at all times which can be noisy. Larger and quieter generators are available, but you should expect to spend quite a bit more for those options. Due to higher potential voltage, 120V AC has a greater likelihood of leakage to ground and should always be used in conjunction with a grounded GFCI circuit.

The same math applies when sizing an AC system, though you no longer need to store charge in batteries.

For example, a 120 Watt light that runs on 120V will draw 1 Amp of current.

Ten identical lights will draw a total of 10A.

An 1800W generator is capable of generating 15A at 120V (1800W divided by 120V = 15A). This generator would be large enough to power my ten lights with 5A extra to charge the batteries that run my trolling motor. 

Final Thoughts

• DC systems that utilize batteries are cheap and silent but are heavy and may have limited run time. A DC light setup will likely need a small generator to recharge the batteries for longer outings.
• AC systems that utilize generators are expensive and relatively loud. An AC setup will need a large and expensive generator to run the same amount of lights as a DC setup. Expect to pay more for a quieter generator.
• The electric supply setup will take up much less space and weight if it is designed as a system rather than in piece-meal fashion.
• Choose the system that best fits your needs and/or budget. A lighting system is only good if it works.
• Reach out to us on Facebook or Instagram if you have questions regarding your lighting or electrical setup; our co-founder Jon studied electrical engineering at Michigan Technological University.

Photo Credit - Greg Oxford (Bowfishing TV)