Using solar panels to charge rack-mounted batteries is a great way to utilize renewable energy for powering IT equipment. But how many solar panels and watts are needed to fully charge a typical 48V 100Ah lithium battery in a server rack? This article provides solar sizing calculations and recommendations.

Sizing the Solar Array

To properly size your solar array to charge a 48V 100Ah rack battery:

– Calculate the battery watt-hours: 48V x 100Ah = 4,800Wh

– Determine the solar recharge rate: 4-6 hours for full charge

– Calculate solar watts needed: 4,800Wh / 4hrs = 1,200W

– Allow for inefficiencies: Add 20-30% = 1,500W to 1,600W

Given these calculations, an ideal solar array would be:

– 5 x 300W panels = 1,500W

– Or 6 x 250W panels = 1,500W

This 1,500-1,600W solar array would fully charge the 48V 100Ah battery from empty to full within 4-6 daylight hours.