https://www.nytimes.com/2025/09/13/business/used-electric-vehciles.html (paywall)
Bold is mine
QuoteSales of used electric vehicles rose 40 percent in July from a year earlier, according to Cox Automotive, a research firm.
QuoteElectric vehicles have lost value quickly partly because rapidly advancing battery technology has made older models less attractive. A few years ago, most electric vehicles couldn't travel more than 200 miles on a charge. Now cars that can go 300 miles are common, and within a few years 400 miles will be the norm.
Prices of new electric models have also come down, with many selling for less than $40,000. That automatically pushes down prices of pre-owned cars.
I bolded that because a couple weeks ago we had a 13 power outages for a total of 40 hours in a week and even in late August, our battery bank barely makes it from sun off the panels to sun on. Partly this is the result of changing out some appliances for electric, partly decrease in battery capacity, mostly a function of the fact that telling renters we are on battery power so please watch consumption, did not inhibit them from keeping every light in the house on.
Anyway, we bought 3 x 3.8 = 11.4kWh initially. Seemed like it should last 24 hours based on normal usage, but already it doesn't. If we had bought 4 x 3.8 we'd be fine.
So I looked into buying another one of the batteries we initially installed (no longer made but still available for sale). Strangely, they are the exact same price as when we bought them.
That means that it costs $2600 plus shipping to bring us up to 15.2kWh.
If we start from scratch with the Ruixu 16, we get 16kWh of brand new battery for $3300
delivered without having to mix and match batteries. And because we had an issue with our inverter (replaced under warranty), I think we also harmed the batteries (the low-battery cut out was much too low, drawing the batteries to essentially 0% which is not good for a battery, obviously).
Anyway, point being that it's like PCs in the 1990s - after a few years, the cost of replacing a motherboard to end up with a old dog was too close to the cost of just starting over and getting a zippy new one.