Quote:
Originally Posted by KJNN
I'm wondering why I can't get more out of these batteries than just a few hours of watching tv. Shouldn't be so, right????? Is this a battery problem? An inverter problem?? seems strange to me....
thanks for any ideas
|
Group 27 starting battery has about 25 ah of usable amperage when new. Group 27 marine batteries have about 40 ah of usable amperage when new. Group 27 true deep cycle batteries have about 50 ah of usable when new. Your inverter is a modified sine wave and has an efficiency of about 70% at 1/4 load. So to supply 2.5 amps @ 120 volts takes 35 amps @ 12.2 volts.
Your converter will supply about 50 amps @ 14.4 volts (typical inverter), but when the batteries reach about 80% charged, the amperage tapers. Typically the last 20% of charge takes 3 to 4 hours depending on the battery type, converter, converter temperature and the battery temperature. This is one area where AGM batteries excel. Because of their low internal resistance much less of the charging current is changed into heat; thus. AGM batteries charge faster.