Draper 53488 BCI2 12V Smart Charger and Battery Maintainer (2A)

Does more than just charge 12V vehicle batteries.
Can be connected to a battery for a long duration and it will monitor the power and slow it down to prevent any overcharge.
LED light will flash at each stage of charging: 25%, 50%, 75%, and 100%.
Suitable for winter charging in temperatures as low as -20°C.
Easy to use and cost-effective solution to keep batteries in good condition all year round.