How to wire in a solar panel charging system?

Hi

My disco has a dual battery system whereby the 2nd 12V battery is trickle charged via a regulator when the engine is running - this system came with the car when I bought it.

I have just purchased a 80W solar panel and controller that I want to add to the 2nd battery charging system (I intend to mount the panel on the roof)and have a few queries as follows re: how the tickle charge and solar charging systems will work together (or not) and wonder if anybody can help:

- Can I use the same input/connection into the battery;
- and if so where do I link in the cables from the solar charger i.e. between the battery and the existing regulator (and is this simply just splicing the cable together)?
- how do the two systems work togther and switch between themselves i.e. is it automatic? I assume when the engine is not running only the solar system will be working, but when the engine is running will both work in tandem or does the trickle charge system overide the solar?

Many thanks in advance,

Nick

I'm very interested in the solar charger system as well.

I have my own solar generator I charge a battery up with using a solar panel mounted on the top. I use this to jump start a flat battery when I leave the defender for long periods for offshore work.

I am keen to have a few panels mounted on the roof as well. This will make luggage stowage on the roof tricky as some roof rack systems will interfere with it a bit I expect.

I plan to mount a couple of big 50 kilo industrial batteries on internal stowage areas and have a solar panel system charging them up.

I think, personally, that charging up batteries separately using the solar charger system is wise. Keep them in parrallel for added amperage.
Have you got any details on where you got your voltage regulator from?
I got one from Maplin but it's called a different name and is designed for 2 batteries.

Here's my battery / solar generator...

I think if i was going to wire solar panels in to the system described, i'd be temped to put a relay in line with a feed from your 'engine run' live to energise it. I'd have the aux battery trickle charging as it normally does when the engine is running, then as soon as the engine stop's the relay would de-energise switching to solar pannels for charge. i'm sure there may be other ways to do it, but i'd go for something like this as it would all be completly automatic.

There should not be any need to fit isolating relays , the two methods of charge should be able run concurrently . The regulators will take care of levels , as both are limited by resistance anyway .
Just connect the two wires direct to 2nd battery from solar regulator same as trickle charger or if you wish more convenient to wires from trickle charger regulator on 2nd battery side not on input side . They should self reg , think of it like filling a water tank from two hoses as the battery charges and the resistance goes up the regulators will sense . HTSH

I connected the panel regulator into the battery in parallel as described and now having used it on a 2 week holiday can report as follows:

I have concerns re:the regulator (a Juta 12v/12Amp PWM like the following http://www.dako.co.za/solar_regulators_10-20A.html ) as having connected it up and tried to decifer the instructions (which seem to be a poor english translation) :

1) when in bright sunlight if I take readings off the regulator connections - I got approx 20 volts from the panel '+' and '-' connections and 18 volts from the controller connections to the battery - I thought the controller was meant to lower the volts going into the battery down to approx 12 volts - surely this high voltage is too high?

2) the 'Battery' red LEDs do not seem to work as I might expect i.e. the bank of three red lights seems to change depending on whether the panel is in shade or not, wheras I thought these were meant to indicate the condition of the battery (it has been suggested these might be 'voltage loading indicator lights' as opposed to battery condition lights).

3) It has a green 'Charge' LED which I thought indicated that the battery was being charged but it never seems to go off (i.e. when the battery is full) - also it is meant to flicker when float charging (though I have not seen that)

4) It has a green 'Load' LED which I cannot decipher what this is meant to indicate (I have nothing attached to these terminals)

5) At dusk my battery pack (and sometimes the regulator) starts making a load clicking noise it is so loud I have to unplug the panel - once it is dark everything is ok again (it also does the same at sunrise, but again calms down once the sun is up)- It is almost as though the battery pack charging system can't decide whether it should be on or off?

6) I am not convinced the overcharge on the panel regulator is working correctly as I can see no eveidence of it going off, although sometimes (a bit like at dusk/dawn) when the battery pack shows the battery as full the regulator starts making a loud clicking noise.

Any help/ advice would be much appreciated,