I am currently in an engineering project which is attempting to hook up some solar panels to run an irrigation pump. Right now, the pump that we have is a marine Bilge pump that says that at 12 Volts and 7 Amperes it can pump at around 3.3 Gallons Per Minute. We were provided with a standard zinc-lead car battery that produces 12 Volts. We hooked the pump and battery up, and measured its flow to be around 1.07 GPM, with the battery outputting around 1.84 A and 12.50 VDC. So we know that the pump can take more amperage, but is at its limit in volts. How do we reach this fabled 3.3 GPM? If I = V/R, then we either need less resistance or more voltage, but both seem impossible. Are there other batteries with less internal resistance that are more capable of producing the amperage we need (without such pathetic life-spans that they are useless)? Does anybody know if perhaps marine batteries are more capable at producing amperage than auto ones?