Size Fishfinder Battery for Kayak - Garmin, Lowrance, Humminbird

[@2reelyakrz481]

Our Newport Vessels battery box died a horrible death due to a moderate chop on the bay one day - specifically the electronics in it released the foul smelling magic smoke which makes electronics work 🤣. So, I used the core plastic box (because it's a good design for saltwater kayak fishing) and added several 12v, USB, and terminal connections. The box holds multiple batteries - 1 for trolling motor, 1 for cameras and navigation light mounted on a pole behind the back seat, and 1 for sonar (Lawrence fish finder with side scan) unit. The fish finder is usually too much of a draw for the small 9.x AH lead acid battery and after about 6 hrs the unit will start to act odd (usually streaks through the display or random reboots). I haven't had that issue with the lithium batteries. My guess is that the lead acid battery voltage drops as it discharges and the lithium batteries hold their voltage for a longer percentage of the cycle. So, for the sonar, all new batteries I get in advance will be lithium. The only advantage I see to the sealed lead acid batteries is availability. They can be picked up in the sporting goods section of Walmart, Dicks, Bass Pro, etc and small lithium batteries aren't always carried (or at least in stock).

[@KayakhacksFishing]

You hit the key point. A lead acid battery is only good for about half the rated capacity as a result of something called "depth of discharge."

[@2reelyakrz481]

@@KayakhacksFishing I agree. The issue with lead acid batteries isn't that they go to 50% of their discharge cycle and simply stop. It's that they steadily drop from their nominally rated voltage to a level which no longer allows devices to function properly (ie trolling motors slow down, fish finders don't work correctly, etc). There is physics involved and the physics can't be changed. I see tradeoffs in each battery type and everyone has to decide if the pros outweigh the cons for each type for any given application. I'm not a fan of how lithium batteries are produced, nor of their other negatives. However, for kayaking, camping, or anything else where weight is an issue, lithium wins for me. The same is also true for long-discharge applications (ie battery backup for freezers). For starting cars and tractors, lead acid wins for me as I don't believe their negatives have any significant impact on the application. Different people will have different views for the different applications. The key to making an informed decision is to be informed. I appreciate your comparison of the different types for this application - very informative 😊

[@KayakhacksFishing]

@@2reelyakrz481 Great points! Thanks

[@smokesadventures7587]

Thank you sir for sharing your knowledge of battery power needed and sharing the lithium battery you use. I won a Lifetime Kayak and just starting out doing this kayak fishing I will be purchasing a depth finder and the lithium battery is a better choice to purchase.

[@KayakhacksFishing]

Glad I could help

[@gerrygervais3778]

I’m hope to get a boat this spring and with this info I know what I will get for my fish finder thank you and keep the video coming

[@LI-FLKayakFisherman]

I’ve been using a 6 Ah LiFePo4 battery for my Garmin units. Weighs 1.7#, fits in a $5 Harbor Freight plastic ammo box, 2000 charge cycles and I average over 10 hours usage between charging. Costs around $36 on Amazon.

[@KayakhacksFishing]

Perfect!

[@abnpanzer8229]

Great video.Glad I ran across it as I never considered DoD. Thanks!

[@KayakhacksFishing]

Glad to help

[@Larry77777]

Hey Steve: Lithium-ion is tempting but ... I made my own compact battery box years ago just big enough for a $35 Cdn 9Ah SLA (a 10Ah was dimensionally too big for my box). I found it powers my Garmin 7" (rated 0.8A draw) all day long on my kayak with juice to spare. I always charge it overnight after every use because I have proven it can go over 10 hours but won't last a full two days.

[@KayakhacksFishing]

Great point!

[@johnnelson1625]

Thanks for the video as I will soon be adding a fish finder for my kayak. I will probably go with the Lowrance Elite 9" finder and the Goldenmate 12v 20 ah battery. I am curious about which battery charger to use though... any tips? Thanks!

[@KayakhacksFishing]

Yes, if you get a lithium battery, you need a charger made for lithium. I elected to get this 5A model - amzn.to/3upsviO

[@davidlewis9572]

Just ordered a Goldemate 12 v 20 ah , great info thanks