Solar batteries are used to store solar energy (solar electricity) and discharge power as and when needed. Rechargeable solar batteries are used in off-grid PV systems to store excess electricity. Some solar battery banks use wet cells, while others use sealed or gel cell batteries. Each of these batteries have different temperature, mounting, and ventilation requirements.
NiMH batteries are preferred and most common when it comes to solar energy because they are better than standard NiCAD batteries in terms of charging and release cycles.