Abstract: In a valve-regulated lead-acid battery in which charging is performed intermittently on every short time and high rate discharging to a load is performed in a partial state of charge (PSOC), a valve-regulated lead-acid battery improved for the charge acceptance and the life characteristic under PSOC than usual is provided. A positive electrode plate having a specific surface area of an active material of 5.5 m2/g or more is used. A valve-regulated lead-acid battery is manufactured by using a negative electrode plate improved for the charge acceptance and the life performance by adding a carbonaceous electroconductive material and a formaldehyde condensate of bisphenols aminobenzene sulfonic acid to a negative electrode active material and setting the specific gravity of an electrolyte to 1.30 or more and 1.35 or less.

Abstract: In a valve-regulated lead-acid battery in which charging is performed intermittently on every short time and high rate discharging to a load is performed in a partial state of charge (PSOC), a valve-regulated lead-acid battery improved for the charge acceptance and the life characteristic under PSOC than usual is provided. A positive electrode plate having a specific surface area of an active material of 5.5 m2/g or more is used. A valve-regulated lead-acid battery is manufactured by using a negative electrode plate improved for the charge acceptance and the life performance by adding a carbonaceous electroconductive material and a formaldehyde condensate of bisphenols aminobenzene sulfonic acid to a negative electrode active material and setting the specific gravity of an electrolyte to 1.30 or more and 1.35 or less.

Abstract: An engine includes a cylinder, an exhaust port, an exhaust valve, a secondary air supply pipe, and an electromagnetic valve. The electromagnetic valve is opened in a predetermined time period after a point in time when a lift amount of the exhaust valve reaches about half a maximum value during a time period in which an opening of the exhaust port is opened. This causes air to be supplied from a secondary air supply pipe to the exhaust port.

Abstract: A secondary air supply system includes a CPU, a first air supply pipe, a second air supply pipe, a first shut-off valve, and a second shut-off valve. First ends of the first air supply pipe and the second air supply pipe are connected to an air cleaner box and the other ends thereof are connected to an exhaust port. The CPU controls opening/closing of the first shut-off valve and the second shut-off valve based on a state of an engine. The first shut-off valve and the second shut-off valve are selectively opened by the CPU, so that air in the air cleaner box is supplied to the exhaust port through the first air supply pipe and/or the second air supply pipe.

Abstract: A secondary air supply system includes a CPU, a ROM, an air supply pipe, and an air amount adjusting valve. One end of the air supply pipe is connected to an air cleaner box and the other end is connected to an exhaust port. Secondary air in the air cleaner box is supplied to the exhaust port through the air supply pipe. An amount of the secondary air to be supplied from the air supply pipe to the exhaust port is adjusted by the air amount adjusting valve. A target air-fuel ratio depending on a state of the engine is stored in the ROM. The CPU controls the air amount adjusting valve based on the state of the engine so that an air-fuel ratio in the exhaust port is the target air-fuel ratio.

Abstract: A secondary air supply system includes a CPU, a ROM, an air supply pipe, and an air amount adjusting valve. One end of the air supply pipe is connected to an air cleaner box and the other end is connected to an exhaust port. Secondary air in the air cleaner box is supplied to the exhaust port through the air supply pipe. An amount of the secondary air to be supplied from the air supply pipe to the exhaust port is adjusted by the air amount adjusting valve. A target air-fuel ratio depending on a state of the engine is stored in the ROM. The CPU controls the air amount adjusting valve based on the state of the engine so that an air-fuel ratio in the exhaust port is the target air-fuel ratio.

Abstract: A secondary air supply system includes a CPU, a first air supply pipe, a second air supply pipe, a first shut-off valve, and a second shut-off valve. First ends of the first air supply pipe and the second air supply pipe are connected to an air cleaner box and the other ends thereof are connected to an exhaust port. The CPU controls opening/closing of the first shut-off valve and the second shut-off valve based on a state of an engine. The first shut-off valve and the second shut-off valve are selectively opened by the CPU, so that air in the air cleaner box is supplied to the exhaust port through the first air supply pipe and/or the second air supply pipe.

Abstract: An engine includes a cylinder, an exhaust port, an exhaust valve, a secondary air supply pipe, and an electromagnetic valve. The electromagnetic valve is opened in a predetermined time period after a point in time when a lift amount of the exhaust valve reaches about half a maximum value during a time period in which an opening of the exhaust port is opened. This causes air to be supplied from a secondary air supply pipe to the exhaust port.