Hi All,
I've just finished wiring up the 120W MPPT system in my Starfire. I've mounted the controller in an overhead locker and have a 4 metre run to the battery. It meant I could use existing trunking and void spaces to run the cables. At 11.30 full sun I am getting 5.5 amps at 14.48 volts. This is on a new battery which has had only one trip away. It has had little charge taken from it . At the battery I am getting14.12 volts. Ahh ha I hear you say. You shouldn't have used such long cable runs! I've used 4.5mm2 cable from an auto shop and fused all the lines including one at the battery positive. The interesting thing is that I am losing as much volts in the fuses as I am in the cables. Using my (expensive) multimeter I am losing 0.18V in the cables and 0.18V in the fuses. With 14.48 volts at the controller I am getting 14.35V at the output of the fusebox (-ve and +ve both fused as I've seen done on here). So I've lost 0.13 volts before I've gone 12 inches. All spade connectors have been soldered (I don't trust crimps). The fuse at the battery is dropping the other 0.05V. I've heard a lot about using correct sized cables to avoid volts drop but nothing about what losses the fuses will introduce.
Has anyone else done any tests like these? I'm tempted to remove the fuse in the battery negative line and gain myself 0.06V or so.
I've just finished wiring up the 120W MPPT system in my Starfire. I've mounted the controller in an overhead locker and have a 4 metre run to the battery. It meant I could use existing trunking and void spaces to run the cables. At 11.30 full sun I am getting 5.5 amps at 14.48 volts. This is on a new battery which has had only one trip away. It has had little charge taken from it . At the battery I am getting14.12 volts. Ahh ha I hear you say. You shouldn't have used such long cable runs! I've used 4.5mm2 cable from an auto shop and fused all the lines including one at the battery positive. The interesting thing is that I am losing as much volts in the fuses as I am in the cables. Using my (expensive) multimeter I am losing 0.18V in the cables and 0.18V in the fuses. With 14.48 volts at the controller I am getting 14.35V at the output of the fusebox (-ve and +ve both fused as I've seen done on here). So I've lost 0.13 volts before I've gone 12 inches. All spade connectors have been soldered (I don't trust crimps). The fuse at the battery is dropping the other 0.05V. I've heard a lot about using correct sized cables to avoid volts drop but nothing about what losses the fuses will introduce.
Has anyone else done any tests like these? I'm tempted to remove the fuse in the battery negative line and gain myself 0.06V or so.