What is the best buy on and Lithium batterie and charger for Electronics.

check out Amped Outdoors. Best prices I've seen

You would have to define "best buy". I got a smoking deal on 3-60ah trolling batteries from Amped Outdoors a year and a half ago and they are awesome. BUT, the 125ah Ionic starter battery that I got a good deal on from "Drewtick" on BBC is a beast as well and comes with bluetooth and an app that tells me lots of information on the battery anytime I want to know it- most importantly the level of charge. I bought the 125ah first and was really torn on which trollers to buy....but the extra 10ah of the Amped batteries and the price ultimately made that decision for me. Some people would rather spend a bit more money and have the app, and I 100% understand that as well.

I just got back from the 2021 Crappie Expo and everyone I talked to from the Lithium Battery guys to the Boat Dealers and it was hands down, do not put a lithium battery on your starting motor.

Yet WRM is offering them on Nitro's, Triton's, and Rangers from the factory.

Must of talked to the wrong people at the booths. You can run lithium battery’s just fine as a cranking battery as long as the BMS is good in the battery. I’ve installed several on the cranking side with zero issues. I know 3 dealers at the show who would put lithium cranking batteries in any boat. Bass Pro wouldn’t be pushing them in his brand of boats if it wasn’t a true working battery

The only thing I don’t suggest is running a single 36v troller battery unless ur buying one 36v for a spare. That’s due to fact of it might go down and leave u without a troll system unlike the traditional 3 battery 12v set up where u can swap a wet cell in to get you by.

Exactly....the boat MFRs are doing but the motor MFRs are like nope, don't do it, you'll pay

If using a battery purely for starting the boat engine, lead acid are perfectly fine for delivering a quick burst of high amperage (which discharges the battery maybe 2%) and then the alternator from the engine recharges the lead acid battery back to full charge quickly.

Not just small size and low weight, the advantages of lithium batteries include how deeply the battery can be discharged and the high number of cycles the battery can be recharged over it's lifespan.
Lithium batteries can be discharged as low as 80%, while lead acid don't like to be discharged deeper than 50%. Thus, lead acid batteries are perfectly fine dedicated to the starting motor because they don't get deeply discharged as long as the alternator recharges the battery, or you maintain the battery on a charger when the boat is moored.

Then, there's the issue of the alternator on the motor being designed to recharge lead acid batteries (not lithium batteries). Lithium battery chargers have built in over current and over voltage protection while charging (lithium batteries don't like over current charging when full, while lead acid batteries tolerate this just fine); thus charging from a standard alternator is best for regular lead acid batteries.

Umm Mercury is fine with Lithium battery’s and so is Yamaha as long as it has a proper BMS system unlike a lot of the first lithium’s that didn’t causing tons of issues pushing them motor mfr to put out the notices

Well over 2 years, 200 motor hours on my Ionic 125ah starting battery. Also run two Carbon 12s, a Helix 12, Mega 360, lights, livewells, etc on it. (2014 Yamaha 250SHO). I do not think I have ever seen it below 70% on the app and have not had a single issue.

What about all the accessories that run off the cranking battery.
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If I used a lithium battery as the cranking battery and also to run bilge/electonics/etc; I would make sure the lithium battery has a good battery management system (BMS) to prevent over current charging, and I would maintain charge it with a lithium battery charger (I would not just rely on the alternator to keep it charged). Alternators typically stop charging batteries at 13.9 volts. 12 Volt lithium batteries require to be charged to 14.5 volts to fully charge.

A few weeks ago Brunswick Marine (owner or Mercury Marine) bought ReLion. That ought to tell you something.

Just think about this....the known manufactures of lead (Intestate, Duracell, Optima, etc) have zero lithium offerings. Just like lobbyist and politicians...the long standing relationships with boat manufacturers run deep and none of those big manufacturers of lead batteries want to see battery life extended in years as that affects business for both parities.

The more competition will drive down cost, so even though early adopters pay more now it will eventually come down as the market (bass boat owners) demand the better product.

What may likely happen is the Ionics of the world will be offered millions and bought up by an Interstate. Then they just flip the marketing switch and re-wrap their branded NASCAR in Ionic logo's and they are off to the races.

Speaking of Ionic batteries, they just upped their warranty from 8 to 11 years!