18 Feb
                
                    2020
                
            
            
                18 Feb
                
                '20
                
            
            
            
        
    
                6:17 p.m.
            
        There is power backup and then there is power backup. The former is a small power pack (batteries, supercapacitors, whatever) that will allow the microcell to weather a short blackout or brownout. We are talking seconds, to bridge switching transits. To be useful in a deployment, such a holdover battery needs to be very low maintenance. (Think about cars that use supercapacitors as a battery replacement -- good for short needs like a single engine start.) The latter is longer-life power to keep the microcell going for days or weeks. It's debatable whether this is mandatory.