DC-to-DC conversion device (1, 1') for a charger for charging a battery of electrical accumulators that is configured to be connected to an external electricity grid, able to operate bidirectionally, by recharging the battery in a forward direction and by discharging the battery to the electricity grid in a reverse direction, comprising at least one full-bridge LLC resonant converter, each full-bridge LLC resonant converter comprising: - a full switching bridge generating a square-wave signal, said full switching bridge comprising a full-bridge assembly having four structures (210, 210′, 210ʺ, 210′′′), each formed by a transistor (301, 401), by a diode and by a capacitor that are connected in parallel; - an LLC circuit, comprising a capacitor and two inductors and excited by said square-wave signal; - a transformer transmitting said signal from the LLC circuit; - a rectifier rectifying the signal transmitted by the transformer, said rectifier being formed by a full bridge having four structures (240, 240′, 240ʺ, 240′′′), each formed by a transistor, by a diode and by a capacitor that are connected in parallel; - an output capacitor filtering the rectified signal; characterized in that each structure (240, 240′, 240ʺ, 240′′′) of the rectifier furthermore comprises a device for eliminating the effect of the capacitor of the associated structure (240, 240′, 240ʺ, 240′′′), eliminating the effect of said capacitor when the DC-to-DC conversion device operates in forward mode. each full-bridge LLC resonant converter comprising: - a full switching bridge generating a square-wave signal, said full switching bridge comprising a full-bridge assembly having four structures (210, 210′, 210ʺ, 210′′′), each formed by a transistor (301, 401), by a diode and by a capacitor that are connected in parallel; - an LLC circuit, comprising a capacitor and two inductors and excited by said square-wave signal; - a transformer transmitting said signal from the LLC circuit; - a rectifier rectifying the signal transmitted by the transformer, said rectifier being formed by a full bridge having four structures (240, 240′, 240ʺ, 240′′′), each formed by a transistor, by a diode and by a capacitor that are connected in parallel; - an output capacitor filtering the rectified signal; - a full switching bridge generating a square-wave signal, said full switching bridge comprising a full-bridge assembly having four structures (210, 210′, 210ʺ, 210′′′), each formed by a transistor (301, 401), by a diode and by a capacitor that are connected in parallel; - an LLC circuit, comprising a capacitor and two inductors and excited by said square-wave signal; - a transformer transmitting said signal from the LLC circuit; - a rectifier rectifying the signal transmitted by the transformer, said rectifier being formed by a full bridge having four structures (240, 240′, 240ʺ, 240′′′), each formed by a transistor, by a diode and by a capacitor that are connected in parallel; - an output capacitor filtering the rectified signal; characterized in that each structure (240, 240′, 240ʺ, 240′′′) of the rectifier furthermore comprises a device for eliminating the effect of the capacitor of the associated structure (240, 240′, 240ʺ, 240′′′), eliminating the effect of said capacitor when the DC-to-DC conversion device operates in forward mode.