lithium battery opinion

"I don't see any advantage for using 2 batteries for a 24 volt system when they're make a single 24 volt battery."
I went with a single 24V battery to make the wiring and installation easier plus it fit into my boat better than two 12V. One advantage to two 12 V is you can use one to start your motor in case the other battery fails.

I went with a 24v onboard charger for my Alumacraft. This is because I did buy a 24v Li-Ion battery. Works fantastic! The NOCO Genius models are a bit pricey.

​24v NOCO Genius 25​​​

Jimmy

I could be wrong but I don't see why it wouldn't work except the on board charger would you need to charge at 24+ volts when charging or would connecting 2 banks to one battery work. All on board Chargers I've seen are 12 volt.

I'm going to ask this question again...

Why use 2 12 volt batteries rather a single 24 volt battery?  I'm going to upgrade next spring.  I need to upgrade my on board charger regardless because mine doesn't do lithium.  

I don't see any advantage for using 2 batteries for a 24 volt system when they're make a single 24 volt battery. 

WE PUT 2 12 VOLT DYNESS BATTTERIES IN MY FRIENDS BOAT THIS YEAR.   GOT GROUP 31'S FOR ABOUT $340 FOR BOTH ON LINE.  THEY ARE AWESOME WE HAVE ONLY HAD TO CHARGE THEM ONCE SO FAR AND THAT WAS AFTER ABOUT 12 DAYS OF CONSTANT USE ON THE ULTERRA.  THE BATTERIES WERE ONLY AT 35% WHEN WE PUT THEM ON THE CHARGER.  I WILL UPGRADE TO LITHIUM NEXT TIME, BUT BOUGHT GROP 31 AGM'S A YEAR AGO FOR MINE.

For those upgrading to Lithium batteries a little something to consider. It is recommended to store your batteries at 50 to 70 % State of  Charge. This means it is not good practice to leave the charger plugged in continuously. I bought a 2 bank charger for my lithium batteries and don't usually plug them in until the night before I am going fishing. I then put a small battery maintainer on my starting battery that I leave plugged in. Keeping lithium's at 100% puts constant chemical stress on the cells and shortens the life span. I'm going on year 4 and so far see no measurable degradation.

Isn't a 55# Terrova a ​12v trolling motor?  How can that work with a 24v battery?

I just bought a 24 volt 100 Ah XZNY lithium ion battery on Amazon for $409.  I have a new Terrova 55 pound spotlock trolling motor. Used it in Fremont on the Wolf River for 4 days and still had 40% charge. Very happy with it so far.  $400 about same as 2 12volt lead acid batteries.  Did need to buy new charger for higher current but very happy with battery

Thanks migr8r!

I put an isolated 54ah lithium battery on my boat exclusively for my electronics. I’d only get about 7-8 hours of run time with my 2 dash units on. That wasn’t long enough for me. I ended up putting in a 100ah battery and it’s been much better. 

Figure each of those units are drawing roughly 3-3.5 amps/hr. If both are on for 8 hours, that would be in the neighborhood of 48-54 amp hours. If you only ​have those units on sporadically for a couple hours while out, you could get away ​with a ​50-ish ah battery. If you were using them for a longer period or wanted to be able to go a day or two without charging, 100ah. 

Recommendation for lithium size to run Solix 15 and Xplorer 9.
Thanks.

I agree about Ulterras, which is why I have a Terrova.  The difference though is if my battery were to have a problem, I still have my kicker motor or an anchor.  If the Ulterra has an issue, you are screwed.  Saw some guys playing with one at the launch last spring around midnight because it would not stow.  That was a perfect example as to why I will never buy one, I can walk a few steps to lift it up and not worry about it.

If you have newer AGMs, I would also wait until they ​get old.  No point in changing ​batteries at that point.

During my research for lithium batteries, I specifically called Minn Kota and was advised to use multiple 12V batteries vs 24 or 36V. That was a few years ago and may be different now. There was a good reason but I don’t recall exactly what it was. It would be worth calling Minn Kota and asking. 
One thing that also may have changed now was that trolling motors weren’t supposed to be run at full power with lithiums because they produce more voltage and would burn the motor out. I can run mine at 70% power and troll at 2mph. I will run at full power in short bursts if needed but not for more than a minute or so. Newer TM’s may be different now. 

As for running in cold weather, I frequently fish in sub freezing temperatures and never had my lithium batteries shut off. Given that lithium batteries are frequently used for locators while ice fishing in well below freezing temps, I really can’t imagine being in a boat in such cold weather that it would cause a lithium battery to shut off. To my knowledge, it’s only charging in sub freezing temperatures where it’s a problem. 

Ulterra's were supposed to stow and deploy without getting stuck, too.
Most of the bass pros that I talk to do run lithiums.  Just a lot of benefits to them.  But they also carry their AGM's with them "just in case".  And many have needed them in the early spring.

Again, for me right now, it's AGM.  In another two years, I'll re-evaluate.  That technology is always going to improve.  Prices are going to come down even more. 

When I was looking at them, I run 4 batteries in the boat.  3 are for the trolling motor.  I absolutely loved the "combined" 36 volt system with the lithiums.  I can't recall the difference in weight, but it was really, really substantial.  And the whole system looked very easy to connect and maintain.

I mention that because that one system for 36 volts was not a feature or "thing" a year prior when I was looking at batteries.   These kinds of things always evolve.

LiFePO4 batteries for trolling motors can safely discharge/operate in temperatures as low as
-4°F, so that would be ice fishing.