2V 800ah Battery bank

Chriszam

I have four strings of 48 2V 800ah batteries set in series then in parallel to give me 48V. I want to run 6 11kw hybrid inverters set in parallel off them.

Unfortunately they are down to 26.7 volts. Some are even below 1 volt. Can the hybrid inverter charge them and what current can I put them on as the inverters have max 150A charging current.

If I need to charge these batteries before putting them to work with the inverters what kind of charger and capacity do I need. These are ofcourse AGM batteries 

Marc Kurth

Always rely on the manufacturer data for max charge rate because it varies widely. Example: A single string of Concorde Sun Xtender 900 ah 2v AGM will very happily accept a 500 amp charge rate when cool. In true deep cycle industrial applications, they recommend 200 amps as the minimum charge rate for that battery. Those numbers are totally unacceptable for some other manufacturers.

Based on the voltages, your batteries are likely already beyond any useful life due to sulfation. Trying to recover from such an extreme deep discharge requires a specialized charging routine with an elevated voltage at a reduced current over a long period of time, while babysitting the process to avoid excess heating. The exact steps and voltage/amperage requirements vary with the internal construction details of the battery. Keep in mind that extreme sulfation can cause a partial short inside the cells.

What brand, model, and age are the batteries?