Lets try this again...walmart replaced my dc batteries.

[73powerstroke]

Zero charge/float applied?

Got a hydrometer to check specific gravity? Those might be a little more concentrated than is typical.

Unfortunately the battery is sealed. It's never been placed under a load if that makes a difference

 

[73powerstroke]

When I had them, they always lasted at least 5 years. Some longer. However, I did not run them in series.

I'm serious thinking about going back to 12v to avoid the balance issue. This mpp solar hv lv2424 doesn't work how I like anyways and I have 3 epever 40amp tracer 4210an charge controllers and some cheap 12v inverters anyway

 

[Browneye]

When I had them, they always lasted at least 5 years. Some longer. However, I did not run them in series.

If they are not abused they certainly last longer. I've had them in boats and RV's over the past forty years as well. If you discharge them below 50%, or allow them to rest in a discharged state, their lifespan is significantly reduced. Which is generally what ends up happening with most users, and hence my comment.

A 'marine' or 'RV' battery rating means it generally has heavier lead plates, which is another way to judge battery quality - better ones weigh more, they have more lead in them. And based on this simple fact, 6 volt batteries are more durable, and why golf cart batteries have been the go-to for so many marine and rv applications over the years. You generally get more usable amps and longer life. But they all need to be kept fully charged, and a regular equalization charge of 15V or so that burns sulfate off the plates greatly extends their life. An even better option if you need a lot of amp-hours is an industrial battery - for forklifts, heavy equipment - 4D or 8D types. They are deep cycle and very heavy, and last even longer if properly maintained. And very expensive.

Moving up to LFP was a whole new experience, and a lot more complicated than the old-style lead batteries.