Hey Stewart,
I am a solar installer and I have worked with many different charge controllers, but never this particular one. Too bad you had moisture problems, since the manual and the spec's indicate that it is "waterproof", which must mean something else in China.
From the manual, I believe the unit senses sunset when the amperage from the solar panels goes below a certain pre-set level. For example, if a 50 watt panel usually provides up to ~3.5 amps for solar charging, and the incoming amp reading drops to something like 0.1, it just assumes the sun has gone down, so time to start the internal timer chip. One general solar wiring notion to keep in mind whenever you change any aspect of the wires: many charge controllers need to be connected to the battery bank
before the solar panels are connected -- the power needs somewhere to go. Also, the term "load" gets a little confusing when dealing with charge controllers, since their main job is to charge the battery(ies), so the battery bank itself is the typical load. Other DC loads, like lights or fans, are then operated by an internal switch, so there are really two (or more) "loads" to think about.
You might have a bad unit. Here are some things I would check if I were there, and you asked me to try to help you trouble-shoot the system (please forgive me if I state the absolutely obvious; I don't have any way of knowing how much experience you have with these sort of things):
1. Use a meter to verify polarity of solar connections and battery connections, and also the battery voltage (instead of relying on the little green lights). Most meters will give a negative number if polarity is reversed (the RED lead is assumed to be POSITIVE, unless you have an odd meter, which one hopes has the leads labeled with + & - symbols). If you get 14.2 volts with red on the + terminal, that's great; if you get -14.2 volts, the polarity is reversed.
2. This thing says its POSITIVE ground, which is highly unusual in the USofA -- was the earlier model also positive ground? If the old unit was negative ground (MUCH more common), and the replacement is positive ground, you would have to change the grounding connections, as some units will simply not work at all if they detect a grounding problem. Check that the grounding is still good, and still on the proper side (+ vs -).
3. Check the voltage coming in from the solar panel(s), too. While removing the solar connection, could they have been either reversed, or if you have more than one panel, could the wires be combined in series (24 volts, lower amps) instead of parallel (12 volts, twice the amperage) ?
4. Make sure
battery all connections are clean and tight, with no corrosion. A weak connection due to a loose screw or a little corrosion can cause all sorts of unexpected and sometimes weird things. You may be able to measure the voltage through a corroded terminal, but not deliver power to a load, for example. Remove any corrosion with sandpaper, emery cloth or a file, and treat with some sort of lithium grease or even Vaseline.
5. With timer 1 set to #17, it should be in "On/Off Mode" which I take to mean you would be relying on the on/off switch to manually switch loads.... could the
switch be faulty? When pushing the switch, you have only the output to load to test if its working? Try to measure this with a meter, just in case there's a problem downstream, and something about the load is not right (like a faulty bulb...) If you set Timer 1 to say #1, does it connect to the load for 1 hour after sunset (as it should)?
6. I don't know squat about the energizer you mentioned -- is that an AC battery charger?
Can you return the controller, or did you buy it on line by hunting in the mighty Amazon jungle? That's one of my pet peeves about on-line purchasing -- can be a real crap shoot, or even really crappy shooting! If you can return it, try getting a controller from a name brand company, like Morningstar. They have some excellent units that will do what you want, and the manual will be easier to understand, too. Maybe there is a solar dealer near you who can help you in person Often marinas and RV places have good DC power options if you can't find an actual solar geek. Real people are always better than hunting in the jungle of the Amazon!