I have brought a 120 watt folding solar panel , I have hooked it up via anderson plug to my caravan , With the multi meter the house battery has a reading of 12.5 volts , But the reading on the lead from the solar panel is 2.5 volts is this normal
Brickies, that looks as if their might be something wrong, but first we need to understand what you are measuring.
Most people hooking up portable panels, now connect the panel to an extension cable (6BS is good), then connect the other end of the cable to a solar regulator near their battery.
In other cases people buy a solar panel with a regulator attached, then connect this via an extension cable to their battery.
If you are in the first scenario, I would be expecting to see 15V plus on the extension (assumes the panel is in the sun). If you are in the second scenario, then i would be expecting the regulator to be trying to drag the voltage to about .5V higher than the battery.
It is possible that you may be using a panel with a built in regulator, and plugging this into the anderson plug that would normally connect to the tow vehicle, thus the built in diode (stops the van battery discharging through that plug) would be stopping the regulator seeing battery voltage, thus it would not know what voltage to charge at.
Thanks Plendo I am using the last scenario , It has in built regulator and the anderson plug on it is pluged into the lead that normaly plugs into the tug , I brought the set up from low enegery Melbourne , Also there is no power being used in the caravan at the moment every thing is off .
Thanks Juergen , I had to take the panel into the garage so I could see the led control lights to be able to set the panel , It was only putting out 2.5 volts now It ptoducing 13.8 volts
If your panel is only putting out 13.8 V it sounds like you have a simple regulator that is more suitable for maintaining batteries than fully charging them. Do you have a model number and manufacturers name on the regulator?
To see if it is a smart regulator, discharge your batteries a bit. Then recharge them with the panel whilst watching the battery voltage. It should rise to something over 14.0 V initially and when the battery is charged then drop back to 13.8 V.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
Thanks for your reply Peter it is a 120 watt folding solaar panel from Low energry with a kand star regulator , The house battery was showing a reading of 12.7 volts and the panel lead was showing 13.8 volts with no draw on the house battery .
I do not recognise the type of the charger, but the voltage it is generating would be consistent with it being an MPPT controller, where it sets its output voltage just above the battery voltage.
I would be interested to see the voltage once it has been charging the battery for a while, and the battery voltage is higher, say up around 13.5V, I would not be surprised to see the charger pushing more than 14V in that case.
Thanks for your reply Peter it is a 120 watt folding solar panel from Low energy with a Land star regulator , The house battery was showing a reading of 12.7 volts and the panel lead was showing 13.8 volts with no draw on the house battery .
When I gave my previous reply I had assumed that the panel had the usual attached regulator where there was no exposed wiring between the panel and the regulator. Your regulator looks a little different. I take it the 13.8 V was measured at the input to the regulator. (If you were measuring that voltage at the output of the regulator then it means you have a high resistance lead to the battery.)
With the input to the regulator at 13.8 V and the battery reading 12.7 V it means the system is working hard and charging full bore. When the battery charge comes up the battery voltage should rise to around 13.8 V and with little charge current being drawn by the battery the panel voltage should rise towards 20 V. It looks like your battery is not well charged or there is a fault somewhere (perhaps even a dead cell in the battery.) To check the battery condition, disconnect all loads and charging devices before night time. Then in the morning measure the battery voltage and let us know what it is.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
