Just sell it though normal channels. If your battery is with more than your car then there would be people making money on the arbitrage.

I totally get that, but as the owner, perhaps I'd like to make the money on the battery before the arbitragers.

You are getting a base price but the rest needs to be enough to motivate people to handle your batterie and to install it somewhere.

You can convert your batterie yourself into a grid support batterie for your own house to maximize your personal gain.

But you are not doing things on scale, so you need to ignore your personal labor time.

People look for used car parts at wreckers. EV batteries are no different.

Wire it up to a solar panel and use it for home energy?