Fish Finder Battery Box

Hi All,

I have just finished making up a battery box for my new Raymarine Dragonfly 5 pro. Prior to this I had just been using a dry bag but wanted to switch to something a bit more sturdy.

First up was finding a suitable box. I found the Pelican 1120 to be the perfect size for my 12v 7ah battery. In addition to the size, it comes with foam included that has perforated edges so can be cut to size very easily to make a nice snug fit so that the battery doesn’t move around.

Peli 1120 kayak fishing battery box

This is the Pelican 1120 fish finder battery box. It is the perfect size for most 12v batteries used for kayak fishing.

Peli 1120 Dimensions

These are the dimensions of the Pelican 1120. Check this for size to ensure your battery will fit.

The Peli 1120 case is not cheap. A new case with foam will set you back around £35-40. The good news is that they regularly appear second hand on EBay. I managed to purchase 2 in a week both for lesson than £20. This is still quite expensive but the box feels very sturdy and is completely water tight.

You can remove the perforated edges of the foam to give a really close fit to your battery. This will prevent any movement whilst out paddling your kayak.

Fitting 12v battery to Pelican 1120

Fitting the 12v battery to the Peli 1120 box is very simple by removing the already perforated foam.

Once the battery was in place I fitted some female crimp terminals to some short lengths of cable. I included an in line fuse that can take micro fuse blades. This is recommended by most fish finders in their installation manual and will prevent any spikes in voltage causing any damage to your expensive fish finder.

I connected the live and neutral cable to an index marine bulgin low flange socket ( These are expensive (approx £10) but they are so simple to install and offer a watertight seal. Combine this with the index marine plug connected to the fish finder power cable and you have an easy way to connect the fish finder to the battery box.

Index Marine Bulgin socket

The 2 pin Index Marine Bulgin plug and low flange sockets offer a waterproof connection from the battery box to the fish finder power supply.

The finished result is shown below:

Peli 1120 with bulgin socket

Peli 1120 battery box with Index Marine Bulgin socket fitted

I’ve been really happy with how the battery box ended up and see it lasting longer than I will!



5 thoughts on “Fish Finder Battery Box

  1. Hi can someone please give me advice on how to wire up the male 2 pin plug i cant remove the pins to wire it up behind

  2. Hi Guys,

    I made one of these to take out on the Rib and the Kayak and recently had a mishap. I decided to get clever and added a second power coupling to connect a Small solar charger to, to keep the chart plotter rolling all day for long fishing trips/weekends away.
    Well, when batteries charge they vent Hydrogen (even the sealed lead acid ones), this should not normally be a problem, however it seems the Automatic Pressure Release valve on my Peli case was not working, the pressure inside the case built up to levels dangerous enough to Shatter the clips and blow the lid open explosively. Inside a kayak I’m not sure how this might play out, but I can say that the bang was loud enough that we thought our Rib had exploded, and various items sitting on the box were catapulted into the air.

      • Further to my post, we believe that it may not have been the result of a defective pressure vent. The explosion most likely was a straight forward hydrogen explosion caused by movement of a battery contact sparking on the terminal and igniting a small pocket of hydrogen produced by the venting battery. This was quite a loud and dramatic event on a spacious Rib, in the confines of a kayak or canoe it would have been much more unpleasant. So the lesson here, don’t connect any chargers to the battery while it is in the Peli or any other un-ventilated case.

Leave a Reply

Your email address will not be published. Required fields are marked *