Lithium battery for on board fish finder question

[kickingfrog]

Mad money this year is for new batteries for the boat. I'm sold on lithiums for the trolling motor and from the other thread know what I need for my setup. However the information on what I should use for a dedicated battery for the fish finder seems to be a bit more murky. I've got a Garmin ECHOmap CHIRP 95sv. It has down and side imaging. I do fish full days so I want 8-10 hours of use but don't think I need multiple days as I can recharge overnight. I want as much battery as I need but don't think a 12v 100ah is necessary for my finder so the question is: Is 30ah enough or just go 50?

[smitty55]

More is better I would think. Better too much than barely enough, it will keep the battery from getting too far discharged. It's never good to let any battery get completely drained. Plus you never know if you will go on a weekend camping trip where recharging won't be an option.

[Fisherman]

Simple way to calculate is using the mfgrs power consumption info X 12 hours per day for one days use.  If you're going for a couple days, double it.  Double that and it's unlikely you will ever drop the battery below 50% and make it live longer.

[AKRISONER]

30AH is way way way more than enough to power an echomap 95 for a full day. Especially in the warmth.

for perspective, I am able to use a 24amp hour lithium with a 106sv and livescope in the cold for about 7-8 hours

[Terry]

30 amp is good 

and as it turns out with lithium batteries more is not best  lithium batteries like to be between 20 and 80 % full  , so if you never get below 80% and you keep charging it, it hurts the battery and if you let the battery get below 20% often and charge it’s hard on the battery 

I was reading up on this recently and now I have to change the way I charge my lithium batteries too

[Fisherman]

Just looking at the Chirp 90 power requirements, 25 watts or about 3 amps, I don't think the 95SV would be much more than that, so what Terry said should be sufficient.

[Moosebunk]

93SV plus black box and LVS34 with screen backlit 100% has a max draw of 3.2AH. If that helps ya at all. 

Personally, I'd look at the 50AH unless planning to run two or more units. I presume these will be charged off the main motor too.

Off just a standard Interstate crank that I believe has about 80AH, the 9 and 12 inch Lowrance run all day but, that battery is connected to the main.   

[SmokestackLightnin]

I would think if you're running PanOptix then 50ah is ample.  I use the 100ah lithium battery for my Garmin as PanOptix requires a steady 13 plus volts or it will crash.  At least that is the experience I had.  Once I wired to standalone lithium everything works as it should.

I run Echomap 106SV with livescope LVS34 and GLS10.

Edited January 14 by SmokestackLightnin

[Terry]

My livescope starts having problems when it gets under 11 volts 

[Lape0019]

If all you are running is the one fishfinger and nothing else, I would think 30AH is sufficient. I run 2 helix 10's 360, ethernet switch, a 126SV and LVS34 plus box on a 100AH and it gets me through the day just fine. 

[SmokestackLightnin]

19 hours ago, Terry said:

My livescope starts having problems when it gets under 11 volts 

Same, thinking the starting battery was sufficient but the box would shut down and LiveScope icon disappeared from screen.  Found a couple vids on maintaining constant 12.5 volts or better and then purchased standalone lithium battery for Garmin only.  All working good.

[BassMan11]

On 1/11/2025 at 1:51 PM, kickingfrog said:

Mad money this year is for new batteries for the boat. I'm sold on lithiums for the trolling motor and from the other thread know what I need for my setup. However the information on what I should use for a dedicated battery for the fish finder seems to be a bit more murky. I've got a Garmin ECHOmap CHIRP 95sv. It has down and side imaging. I do fish full days so I want 8-10 hours of use but don't think I need multiple days as I can recharge overnight. I want as much battery as I need but don't think a 12v 100ah is necessary for my finder so the question is: Is 30ah enough or just go 50?

Depends on the set up I guess. 

For just the 95sv UHD set up (no livescope and not 2nd gen) it only draws 1amp at 100% backlight. So as a dedicated battery for just this set up you could get away with a 15-18ah if you really wanted. 20 or 30ah would be more than enough. If you plan on acquiring a livescope eventually get a 24ah battery minimum. 

If you decide it will be a "house battery" and run all the systems in your boat (livewell, bilge, music, fish finders etc.) get a 100ah. 

Also if you start to go bigger (20-52ah) be careful to not mistake Lithium phosphate and NMC Lithium ION batteries. 2 different type of batteries and charging profiles/voltages.