I think they will be at 80% after a decade, thus not trash.
> if you’re sealed, and if you get something like OPzS cells and treat them well, you will get 20 years of life from them.
If you have the space, 6V or even 2V OPzS cells can be huge.
So if for example, you need 1600 AH, you would spend $1500 for a 2000 AH lLiFe02 bank, plus 150 for a decent BMS, so $1800 US including shipping. (Just bought our 5th and 6th banks)
For the OPzS, you would need to buy 5714 AH to get the same cycle life and longevity, plus you have to write off 38 percent of your charging energy due to voltage and discharge rate discrepancies vs about 10 percent for the LiFeO2.
I seriously doubt you could obtain 5700 AH, shipped to your location, for less than $1800.. and then the size, maintenance, and corrosion issues (some of that goes away with the considerably more expensive sealed designs) also add to the headache.
If the battery magazine will be subject to below freezing temperatures, both types incur additional risks and energy costs for the lithium, you must heat it prior to charging. For the lead, you will need to add another 40 to 50 percent capacity to meet your target power capacity.
For home brewers, measuring specific gravity at the start and end of your brew process is the simplest way to know how much alcohol is in your creation. For this you'd use a hydrometer: https://en.wikipedia.org/wiki/Hydrometer
https://en.wikipedia.org/wiki/Hydrometer
>Battery hydrometer
The state of charge of a lead-acid battery can be estimated from the density of the sulfuric acid solution used as electrolyte. A hydrometer calibrated to read specific gravity relative to water at 60 °F (16 °C) is a standard tool for servicing automobile batteries.
See also here:
I'd personally not want a lead-acid battery burping flammable gas inside an apartment. They're supposed to be installed in ventilated spaces with drainage holes for any acid that spills out.
I set us up here, totally off grid, three years ago, using a bank of OPzS cells, giving us 42kWh of usable storage. I rarely take them below 70%. Their performance has barely budged since installation, and with the condenser caps, they have required zero maintenance - I check the specific gravity of the acid once a year, and go “yup”, and that’s it.
LiFePo4 I am considering for a booster bank at our cabin, which is 500m from our power shed, as the cable limits us to ~2.5kW here before we see significant voltage drop - it’s either that or step-up/step-down at either end, but transformers are surprisingly expensive. Main reason I’m leaning towards them for this application is mass, as our only access is either by foot or an aerial cableway - our lead bank weighs about 2000kg, equivalent LiFePo4 is about 450kg.
So - LiFePo4 is a decent choice, but depending on your application, a pile of big lead acid cells can be better. See, for instance, storage at various solar projects - it’s virtually all OPzS cells, as the amortised cost is still favourable.