Originally Posted by familyof4
I have a similar question... I would like to run an LCD television and a coffee maker. i know that I need a more powerful inverter than Flicker, but does anyone know how much current the 12V plug can handle (for example, if I were to plug a 3000W inverter into it)? Or, does an inverter have to be connected directly to the battery?
BTW, I have a 2003 Sunseeker 2900 LE...
The problem with large inverters is the battery capacity required to feed them.
For example to run a tv (400 watts or 120 volts x 3 amps) and a coffee maker (1500 watts or 120 volts x 12.5 amps) for a total of 1900 watts requires 1900 watts of inverted dc current.
1900 watts at 12 volts requires 158 AMPs drawn from the battery.
Due to the heat buildup inside the battery at these high amperages, internal resistance will reduce the available capacity by 60 or 70 %. See attached discharge vs capacity curve.
So a 100 amp hour battery will be reduced to approximately 35 amp hours capacity when trying to draw 160 amps out. That means a fully charged battery will be dead (10.5 volts) in 35/160 hours or 13 minutes.
Adding additional batteries will spread that amperage "need" over the number of batteries in the bank thereby increasing each individual batteries capability to supply current. 4 100 AH batteries will have a 400 amp hour capacity but each battery will only be supplying 40 amps of the draw. This will only reduce the capability of each battery to approximately half or 50 AH.
Your FOUR 100 AH batteries will be able to supply 1900 watts for 200/160 or 75 minutes till all four are dead.
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