# Battery arbitrage

In battery arbitrage, when a battery starts and ends the day at the same charge, a common shift in prices affects its schedule only through round-trip losses, so decision-focused losses identify the forecast level only weakly; clipping forecasts to a price cap can lower prediction error while removing profitable spreads. On 1,158 holdout days of the Indian day-ahead market, an equal-weight average of three statistical forecasts did better than the five decision-focused variants tested, and on 53 later heavily capped days no variant beat the regression or the average.

In battery arbitrage, when a battery starts and ends the day at the same charge, a common shift in prices affects its schedule only through round-trip losses, so decision-focused losses identify the forecast level only weakly; clipping forecasts to a price cap can lower prediction error while removing profitable spreads. On 1,158 holdout days of the Indian day-ahead market, an equal-weight average of three statistical forecasts did better than the five decision-focused variants tested, and on 53 later heavily capped days no variant beat the regression or the average.