anyone regretting lithium trolling motor batterys

Jabberwalker- That's awesome terrific report. You hit the nail on the head with the weight difference- so much better than the 70 pounds with those old lead acid. And bonus, you never have to worry about tipping one over, or all the vibrations killing. Congrats on your purchase, I'm on my 3rd season and couldn't be happier with them.

Initial report on my WEIZE batteries:

They arrived packaged nicely surrounded in foam, charged to 13.24V & 13.21V, and shipping was very fast. What a weight difference compared to my old batteries, about 25 lbs each. Charged them up and let them sit overnight before connecting them in parallel as stated in the manual to balance them. After about 20 hours they both settled in at 13.42 volts which according to manual is 99 to 100% charge.

Hooked them up to my 24V Terrova and spent 6 hours fishing the Fox River in heavy current today near the dam, using spot lock, and the trolling motor for moving around the entire 6 hours. I measured the voltage at the plug when I got home at 26.49 (13.24 each) which is still 80% State of Charge. So it's early, but so far so good!

One thing that stood out to me in the manual was that from 70% to 40% charge is only a .1V drop.

I’ve had ionic for about a year. Love every bit of them. About 1/3 less weight, smaller, charge faster.
 Ionics have an app you can download to your phone. Which will give all the technical info you need about the condition Of each battery

So far so good on mine. I’m on my 3rd year only, but I have a 36volt ghost, and I run all day with plenty left for day 2 if I want. Charges fast. Lighter in weight. My only issue was on my starting battery. Must have had a draw over the winter last year. It was so dead it wouldn’t take a charge. Now for winter, I disconnect the battery after charging it full, and it’s good. 

Jabber- A multi-meter would do the trick. I don't know if newer trolling motors are wired differently but if I couldn't reach my batteries I would just hook the multi meter leads to the trolling motor power plug. Mine's right at the bow so easy to reach. Or just get long leads and leave them hooked up to the batteries? I test mine under load right before I come off the water. All that said, I don't fish for more than about 4 hours per day so it's not really critical for me.  

Wally Pike....... How do you know how much charge you used? Did the Battle Born's come with some kind of gauge or do you actually measure the voltage? My batteries are buried under my rod storage area, kind of a pain to get at! I already know my Minn Kota battery meter will not work as it is based on lead acid battery voltage.

One thing to pay attention to is the minimum storage temperature, which is usually given as -20C to -25C, or about 0 degrees F to -10 degrees F, depending on brand.  Unlike lead-acid batteries, lithiums don't tolerate very low temperatures.  So, if you store the boat in an unheated area, it would be a good idea to remove the batteries over winter around here.

Sure you might save money by getting the Wietz. Unless it starts cooking off; it's your gamble.
I refer to LiONs as such for brevity I know the difference between them and LifePo4's. Yes you're correct, it's from overheating/overcharging. Why? The reasons I stated- cheaper components and shoddy assembly to bring them in at a cheaper price. Maybe you do ok saving a buck or two, maybe your batteries cook off and start other things on fire. Your call.
Just like anything else, you generally get what you pay for. Let's see how everyone's doing at the 5 year mark, that's about all that can be said at this point.

I will point out that the BattleBorn batteries, at $925 each,  are more than 3X the price of the Weize batteries mentioned.  Which means, if you get 4 years out of the Weize batteries, you are ahead of the BattleBorn alternative.

Don't confuse LiFePO4 and Lithium-Ion batteries:

LiFePO4 (Lithium Iron Phosphate) are the safest type of lithium battery because they are not prone to overheating and even if they're punctured, they won't catch on fire. To ensure the utmost safety and minimal impact, the chemistry utilizes only environmentally acceptable materials and has zero emissions with no venting needed.

The main cause of fire or explosion of a lithium ion battery is excessive overheating during charging, which causes a perpetuating reaction called thermal runaway. Without proper management, thermal runaway may result in fire.

Mendota- Give Battle Born in Reno a call, they can answer all that for you regardless if you buy from them or not.

Jabberwalker- Good to know, I should have caveated my info by mentioning my research was a couple years old. That said, the biggest buying factor IMO is how they're assembled and the quality of the parts. Battle Born are one of the extremely few assembled in the US. Them and Braille last time I looked. All the ones I looked at have a "10 year warranty" but they differ in the fine print of what that covers. Almost all the LiONs you hear about spontaneously combusting is because they were ?shabbily put together. Everyone's comfort level about that is different I guess.

Edge- The time it takes to charge depends on how low they get, but I've never not had them ready after charging overnight. Might even be faster, since they're not "deep cycle" and don't need that slow charge. Also, you don't HAVE to recharge them as often as the lead. If you only used 1/4 and plan on doing the same fishing the next day just leave them. As far as winter care/ storage, it's about the same or better as leads. Protect them from freezing/ excessive heat and that's about it. Since they don't discharge like leads though, you don't have to give them the occasional re-charge. The nice thing is it's a whole lot easier to move them around since they weigh significantly less.

Does it take longer to charge and what about winter care?

All the Batteries mentioned below offer models with built in heaters. Some even offer Bluetooth monitoring that offers real time State of Charge info.