The SmartSolar charge controller will even recharge a severely depleted battery. It can operate with a battery voltage as low as 0 Volts, provided the cells are not permanently sulphated or otherwise damaged. Models: 12/24/36/48 Volt.
 
Data sheet: https://www.victronenergy.com.au/upload/documents/Datasheet-SmartSolar-charge-controller-MPPT-250-70-up-to-250-100-VE.Can-EN.pdf
 
Dimensions
0.29m x 0.16m x 0.33m
Volume
0.015312m3
Weight
5.5kg
Voltage
12/24/36/48 Volt