Another slightly cheaper option is going to a smaller dedicated cranking battery in agm then lithium's for everything else. 4 12v 50ah lithiums will run a 36v ultrex all you can push it plus your electronics on the additional 12v. They have the same footprint as 2 29 series leads.

A single 50 will not run all your electronics all day. Friend of mine tried that. A single 16” Live with active target, first time out he ran it down to 13% in a tournament and didn’t have it on the whole time

This is correct on the 50A, but if you connect it to the cranking battery with a Yandina Combiner, and move around on the big motor from time to time, it will recharge enough to last all day.

If you aren't recharging off the big motor, better have at least 125A, the units and AT pull more amps than the specs say.

Not a knock to the Yandina but to me it would be a worthless expense. Unless you’re making long runs it ain’t going to do squat. A 5 minute or so run to here or there isn’t enough run time to make a significant difference.

You would be surprised what a few 5 or 10 minute runs do over a few hours. The big motor is putting 16 or more amps into the lithium battery. It will make the battery last all day. The draw with 2 sonars and AT is about 7-8 amps.

You could probably just parallel it with the cranking battery and do the same thing and save $80. The Yandina is just a voltage - sensing relay switch.

16 amps in 10 minutes, thats one heck of a charging system. My SHO puts out 50ah. A 10 minute run would be less then 8 amps provided the rest of the electrical system wasn't using any. Like I said, unless you're making long runs it don't do squat. Oh, my 125a Ionic has more than enough juice to last a whole day without starting the big motor.

My Ionics 50 AH will run three 12" units plus Livescope for 12 hours.

As in 2 are on standby and the one with LS is running? It’s not possible any other way. With all 3 on, it’s 7-8 ah total. I had 3 12’s on a 50 and it lasted less than 8 hours, had to go to a 125.

Nope. All three Echomap Ultra 122sv on 85, 90, and 100% brightness. Lasts 12 hours.

The Echomap Ultra 122sv typical current draw is 3a and max is 3.3. Livescope draws about 2a. So about 11a draw and you're claiming a 50a battery lasts all day. Have to throw the BS flag on that one.

You can call BS all you want, but I have no reason to lie. I'm not sponsored by any battery company, and even then, I wouldn't make a claim that is false. My reputation is too important to me. Maybe you're confused on your amp draw, but my boat is my office, and I'm in it 200+ days per year. I know what my equipment is doing everyday.

Edit: In thinking about it a little more.....the only way I could be wrong is if it isn't wired the way it was supposed to be wired. All three units are supposed to be coming off of that one battery (dedicated electronics battery). I suppose it's possible that someone could have made a mistake when wiring it up, and they aren't all pulling off that battery like they're supposed to. I don't believe that to be the case, but I won't say it's impossible.

Are you sure it’s not an 100ah? I had a 122 ultra and LS, it pulled over 3ah. Not trying to argue, but it’s just not possible on a 50ah to run 3 -12’s for 12 hours. Even on standby they pull 1ah ea.

I know exactly what I own. It's a 50 AH.

I may have mentioned this already but one of my bass fishing publications I get just ran a story on the life of a lithium battery and one of the things that was mentioned was they had info from a guy that had taken his boat out and ran the trolling motor on high to see how long it would take for the lithium battery or batteries to give up. He clocked 13.5 hours and HE gave up, not the batteries. It didn't say what brand or what size, but I believe if you are making your living or are a serious tournament angler where you are spending multiple days on the water a week, lithium's would be well worth the investment based on all the info out there.

Well, I don’t know then, the math doesn’t work. If you get a chance sometime, can you turn on all 3 graphs with the sonar on and see what the BT is showing for amp loss?