Want to install solar, questions
We recently got our new 2017 Nexus Ghost and I had it pre wired for solar. Nexus provided (in a box) a Zamp 30 amp Digital Controller with the pre wire. My question is how many 100watt paneles well...
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I also have never seen more than 5 amps from my 100 watt Renogy panel, mounted flat on the roof - so up to 6 panels on the PWM controller. Make it 5 for safety and because the sun is higher in the sky in the USA.
I had about 14.2 volts to the house batteries from the engine, while the engine battery saw 14.5. The voltage drop wasn't in the wire (about 50 ft of #12 I think). The flow was from engine to battery area, then way over to the battery isolator switch (no relay in my rig) and back to the batteries. The drop was in the switch and a Ford connector under the floor. It took a while to find using a voltmeter and long a long wire to a good ground. I eliminated the switch and 30 ft of wire by running the charging wire direct to the battery rather than through the switch. It helped quite a bit to get 14.4 V to the batteries for part of the driving anyway. I thought engine charging was doing quite well until I learned that the voltage method of estimating battery state of charge deceives high until at least 8 hours after charging ceases.* My batteries died from that deception. The thing is the alternator voltage drops down when it thinks the engine battery is charged so the batteries don't accept even 5 amps from the alternator. A single 100 watt panel with PWM controller made the difference from not enough to all the charging we need in summer.
*see the graph in the last post of this Thread to understand why I call it a deception - and then measure voltage on your own batteries for 24 hours after charging.
I had about 14.2 volts to the house batteries from the engine, while the engine battery saw 14.5. The voltage drop wasn't in the wire (about 50 ft of #12 I think). The flow was from engine to battery area, then way over to the battery isolator switch (no relay in my rig) and back to the batteries. The drop was in the switch and a Ford connector under the floor. It took a while to find using a voltmeter and long a long wire to a good ground. I eliminated the switch and 30 ft of wire by running the charging wire direct to the battery rather than through the switch. It helped quite a bit to get 14.4 V to the batteries for part of the driving anyway. I thought engine charging was doing quite well until I learned that the voltage method of estimating battery state of charge deceives high until at least 8 hours after charging ceases.* My batteries died from that deception. The thing is the alternator voltage drops down when it thinks the engine battery is charged so the batteries don't accept even 5 amps from the alternator. A single 100 watt panel with PWM controller made the difference from not enough to all the charging we need in summer.
*see the graph in the last post of this Thread to understand why I call it a deception - and then measure voltage on your own batteries for 24 hours after charging.
