There are 4 tiers to these batteries:
1) Trash Tier: Usually these are on Aliexpress but will appear on amazon from time to time, these are just striaght up scams with prices that are just stupid low, e.g. A 300Ah will be in reality only 100 AH or have some other scam problem, example:
this guy got robbed, but he was asking for it. Buying a trash tier battery is the same as throwing money in a fire pit.
2) Budget Tier: These will generally have either grade B cells or old stock grade A cells, they generally will meet capacity but as they age the cell balance will become an issue this appears as situations where you can no longer charge the battery to full like 14.4v. Its a problem on the 100AH and is going to be basically be a disaster on the 300 ah as most of these BMS units have a puny 50 mah cell balancer. Budget batteries can not be opened, can't be serviced, and for the most part you will be on your own if something happens.
Examples include: Wiez, Litime, Chins, Zooms, Redodo, Ecoworthy, and generally any random battery you come across on ebay/amazon many people are happy with these initially, but you ask them again in about 2 years and not so happy any more.
3) Legit Cell Tier / Quality Tier: These batteries have verified / certified cells, they stay in balance and usually have some features like bluetooth or even now communication options for inverters. They have good support as in a local USA phone number, priced fairly and generally stand behind their product. Most of the time these batteries can be serviced, opened up and parts replaced. Examples include: Aolithium, Sun Fun Kits, SOK Battery, Epoch Essentials (only the ones that can be serviced), Golden Mate (for now at least). Currently I would say the Sun Fun Kits 300/275 is the best in for the features/price in this category and the SOK being the best bang for the buck with their 280.
4) Top Tier: These batteries have robust construction, are built without money constraints, and are considered to be the best in their class. You will pay more but you will have the least amount of problems. Its also note worthy that if you go this route you will usually need to buy other items to be in there eco system for best results. Examples include: Victron's Official Batteries, Lithionics, Roypow Based Epoch Batteries, Voltgo (mainly for the construction). Buy top tier if you want stuff that just works.
There is another tier that I left off and I call it the legacy tier, brands that used to be great but did not innovate and are now considered overpriced:
In this I place Battleborn, Dakota Lithium, Millertech, Relion, K2O, and various others, basically they exsist because the people that are buying them don't know any better.
As for me I generally go with Either tier 2 or 3, if its not something critical I will go with tier 2, like a battery for a chicken coup light or maybe an electric gate. If I'm going fishing it would tier 3 minimum as I have no plans on being stuck in the water (been there done that).
