[higherpurpose]

You charge your laptop everyday. So it depends on how often you recharge them, which means it will depend on how big of a battery you'll buy. If you buy a 100 KWh battery (probably around $10,000-$15,000), I think that should last most Americans at least several nights to a week? So it might approach 10 years before it starts degrading, and then probably a few more years of charging it every day. I assume's Tesla's batteries will be relatively high-quality as well.

[lsaferite]

Isn't the idea that you keep it topped of and use it when grid power is expensive or missing? That usage pattern would involve multiple charge cycles, perhaps even 365 in a year. I guess it would actually follow the Tesla charging patterns fairly close as well. What is the estimated lifetime of a Tesla's battery?

[vidarh]

If the battery has sufficient excess capacity, you can split it into multiple banks of smaller batteries, and cycle which ones you charge and which ones you use. Add a small computer and you can use whatever logic gives you optimal charging/discharge patterns to optimise for lifetime.