Battery recalls are a bit scary, but it's good you're getting it fixed. Recalls happen for different reasons. Sometimes it's because the battery might overheat or catch fire. The update could help prevent that by better managing the battery's temperature. Other times, it's because of charging problems, like slow charging or errors. The update might fix those. Sometimes, the update can even make the battery work better, giving you more range. Or, it could be to fix bugs in the battery's computer. It could also be to help the car find battery problems earlier. Since it's about the battery, get it checked soon. A day for the update sounds right. Ask the service person why the recall happened and what the update does.