Patent ID: 9735593
Date: 2017-08-15
CPC Classifications: H01M,H02J,Y02E

Claim:
1. A battery system comprising: a plurality of battery packs connected in parallel and each including a switch and one or more batteries connected to the switch in series; a battery state determining unit configured to determine a state of the battery packs, wherein the battery state determining unit includes: a disconnection determining unit configured to control disconnection of the switch of each of the battery packs and a switch controller configured to control opening and closing of the switch of each of the battery packs in accordance with a result of the determined state of the battery packs, wherein the disconnection determining unit is further configured to: calculate an allowable stop period of one of the battery packs, which is how long the one of the battery packs can be disconnected from a load, based on past measured data of the battery packs, season data and allowable currents of the batteries, calculate a demanded stop period of the one of the battery packs, which is how long the one of the battery packs needs to be disconnected for an SOC (state of charge) check, based on past charging and discharging data of the batteries, and, when the demanded stop period is smaller than the allowable stop period, make the switch controller cause the switch of the one of the battery packs to be in an open state.