Solar Panel----just a curious question?
I can understand the +/- wires to the controller from the panels, the +/- wires from the controller to battery, but what are the other +/- wires to the right marked ‘load’ in the instruction leaflet with lots of timer setting options? Is it something that can be used for caravanning?
Thanks.
Comments
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Most of the controllers (certainly the cheaper ones) were originally designed for solar powered street lights and similar applications. The 'load' connection is for the light, and usually has options to set how long after dusk it turns on, and for how long.
There is usually also an option to operate in simple dusk-to-dawn mode. I use the latter on a boat for automatically turning the anchor light on and off. The controller
may also disconnect the 'load' if the battery voltage falls too low, to protect the battery against excessive discharge (often useful on a boat to disconnect a fridge running on battery power). I cannot think of anything particularly useful to use
the 'load' output for on a 'van.0 -
One other thing worth considering with this type of controller is the charge characteristic. They were designed on the assumption that the battery capacity was matched to the expected discharge overnight.
They work fine if you are simply using them to maintain a battery in fully charged condition.
However if you have a large battery (eg 110Ahr) and discharge the battery by perhaps 30-40percent, then they may not work well. Typically they will charge at whatever the PV can provide until the battery reaches 14.4v, and then continue at this voltage
for a timed period, typically 1 hour, before reducing to a float charge voltage around 13.8v. Unfortunately this is likely to be long before the battery has been fully recharged. Unless the timed period is adjustable (it usually isn't) the only way around
this to manually overide the controller .......but then you really need a decent battery monitor to know when you have replaced enough power... and it all gets a bit more complicated
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Thanks, that's all it will be used for charging my 110amp Numax battery. The panel is 150w giving a max of 8.4 amps in good sunlight of course.
Just waiting to get out to try it, but have a lot on over the next few weekends, so cannot get out until the end of February; however I am on the 'final countdown' retiring in 3 weeks,
so will have lots of time then off grid!!0
