[raphaelj]

Couldn't the battery just do, as an example, 1 minute long charge then discharge cycles?

For example, if the electricity price is -28€/MWh (like today in Germany), and your battery efficacy is 80%, you could get paid 28€/MWh charging, then only pay back 22€ discharging, generating a 6€/MWh profit.

[7thaccount]

The wholesale energy markets don't have sub 5-minute granularity anywhere that I'm aware of. In the US, 1-hour is standard in the day-ahead markets and 5-minutes is standard for the spot markets.

There is also the problem that your battery would likely degrade fast depending on the technology.