I have a button on my converter to force it into boost mode, which takes the voltage from around 13.6 to 14.4.? ?That increases the current going into the battery by almost 50%.? The voltage drop for 30 ft of 10 awg wire is .43 volts.? If the drop is proportional to voltage, that would mean a 25% power loss.? That's a pretty big hit.
?
On Mon, Jul 15, 2024 at 10:56 AM, Scott Ellington wrote:
On Mon, Jul 15, 2024 at 01:30 PM, elegy3983 wrote:
All good advice for the first time solar user.? My only concern: I do not recommend the use of self-contained ¡°suitcase¡± solar arrays IF they mount the charge controller on the array instead of next to the battery.? Reasoning is simple: the controller adjusts the voltage/current output from the array to suit the needs of the battery.? Typically the array outputs up to 20 volts, far too much for a 12 volt battery.? So the controller adjusts the voltage down.? Then there is substantial line loss over the wiring from array to battery, and the connector mounted to the camper sidewall.? So after all this loss, the battery may see only 11-12 volts, not enough for a full charge.
?
?
The voltage drop in the wiring isn't really a problem. During the constant-current (bulk) part of the charge cycle, it doesn't matter at all, unless the drop is so large the panel can't supply the required current. In both that and the constant-voltage (absorption) part, the voltage drop just means the charging will take a little longer, but will not prevent fully charging the battery.
The usual Zamp plug on Aliners is connected directly to the battery, which assumes the charge controller will be external. (Without even a fuse, in my case!) I put the controller inside the Aliner and re-wired that plug. An added advantage is that the controller doesn't get rained on.
Scott Ellington
?
