That battery being specced as only having 600 cycles almost sounds like it could be lead acid based, which is usually mentioned as 2 years life of being cycled to 50% depth of discharge.
Lithium Ion seems to have about a life of 10,000 cycles.
A lot of information I see these days is about using Lithium Iron Phosphate Batteries (LiFePo4) which tend to have an estimated life of 4000 to 6000 cycles at 80% depth of discharge. will last a good 10 to 15 years.
You can build a DIY 48v battery using 120Ah cells from Aliexpress for under a grand and that would give a 5.8KWh battery with 4.64KWh of usable storage at 80% Depth of discharge, and then you just need an inverter to connect it to.
Ive become aware of a few things about using cheap Lead Acid vs Lithium in there are a lot of limitations for Lead Acid in terms of both charging and discharging rates and charging efficiencies that I wasnt aware of before starting.
With Lithium batteries you can usually charge them at their recommended rated charge rate for most of the cycle from empty to 95% full with the charge current then dropping down as it heads towards 100% full, and the efficiency of the power going in is high and then you can usually recover a high amount of that stored energy back.
With Lead Acid you can start off with a high charge current going in but as the battery gets charged the amount of current you can put into it starts to fall immediately, which means even if you are producing a lot from solar panels it wont be getting put into batteries and then gets pushed out to the grid if you dont have any devices using it, luckily I have the Immersion heater diverter to make use of this wasted energy, also charging lead acid batteries is very inefficient. But then also when you come to discharge the batteries when demand his higher than your solar production or the suns gone in there is something called Peukerts law to be aware of, basically this amounts to being the faster you discharge the battery the less energy you can recover from it, this is why you see Lead Acid batteries listed with different caapacities based on C ratings.
As an example I have some batteries that are listed as 75Ah at C100 and 60AH at C20, which means if I pulled a current .75 amps from the battery it would last for 100 hours, but then If I instead pulled a current of 3 amps it would only last 20 hours, with a bank of 4 of these running at 48v that would equate to pulling 36 watts for 100 hours for 3.6KWh recovery vs pulling 144 watts for 20 hours for 2.8KWh recovery but you can only use 50% of this in the real world, and then as soon as you starting using more powerfull stuff like a microwave or oven then the recovered amount would drop even further.
Something Ive gotten recently to help see where all my usage goes is this from Amazon.
It has a main current clamp to go on your supply cable and then up to 16 smaller ones that you can use on each of the circuits from your consumer unit to see what it using what either live or historically by minute, hour or day. Its fairly easy to setup but if your not confident with electrics you might need to get someone to install it for you as you need to open the consumer unit to get the clamps in and the unit itself needs tying into the power to both power itself and get voltage information to make the measurement more accurate. You have to register an account with the maker and then it all runs in the cloud and you have an app on your phone and theve just recently added a web console as well.
www.weforum.org
so it’s still cheap from my POV.
