Solar or car charging?

Hi Sapper D,

Can you supply a bit more information, in the van do you have a DCDC charger for charging the van batteries or are the van batteries charged directly by the car?

If you have a DCDC charger are the solar panels also connected to it or do they have their own regulator that is connected to the batteries?

Can you supply the brands and model types?

It is all a question of what setup you have??

In my case I have 4 panels charging 4 batteries with no connection to the tow vehicle.

I always avoid shade (scared of branch fall and mess made by birds) and try to camp in the open. Van is well insulated. Unfortunately it is hard when I have to use a van park as they seem to be obsessed with shady sites and usually shaded by unsafe trees.

Alan

In almost all cases, the source with the highest current input will take preference.

A normal vehicle alternator is capable of putting in something like 60-80 amps, if there is no other controller in the circuit.
If a solar panel is also connected to the battery bank, it would be putting in something like 3-6 amps, depending on the wattage rating of the panel.

When you add a smart "dual" controller, such as the Ctek D250S Dual, the controller recognises which is the higher input and uses that source. Obviously with the high current input available from an alternator, that would be the better source. The D250S then restricts the charge current into the battery bank it is connected to a maximum of 20 amps, (the max. rating of the controller, but this is still much greater than the 5 amps available from a 120 watt solar panel array. Only when the vehicle alternator has been switched off, would the controller select the alternative solar port circuit, if connected.

If I understand your second question correctly, yes, you could connect the solar panel input to the van's charge cable circuit, assuming there is no other controller in the van, which would then confuse each other. You can only have one solar controller in the circuit, whether it is mounted on the back of the portable solar panels, or connected to the battery end of the circuit.

I have a D250S Dual dc-dc charger installed in my van, which uses the alternator input while travelling. When I wish to connect my portable solar panels to the D250S when stationary, I use a second "uncontrolled" circuit from the panels and plug this into the solar panel port on the charger/controller.
Basically, I am bypassing the on-board controller mounted on the panels and relying on the Ctek to control the charging process.
When I connect the solar panel to another battery, (such as the auxiliary one in the vehicle) I use the original circuit controlled by the solar panel's built-in controller.

Note: the 12 pin plug you are referring to, only uses two pins for the charging circuit. So identifying the two pins required, you can make up an adapter cable to connect the solar panel plug to a 12 pin plug fitted to the van's "charge" cable and the solar panel will happily supply its charging current and voltage, into the van's battery bank.

Many van/vehicle installations use a 7 pin plug for normal connection between the van and the vehicle and a second two wire circuit for battery charging, usually utilising Anderson connectors.