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Discussion Starter · #1 ·
I bought a suitcase 13W solar panel thingy from Maplins a couple of weeks ago.
I decided to put it on the dash last week to keep the vehicle battery topped up whilst standing.
I have just gone to start the van up for our trip this weekend and its flattened the vehicle battery completely.
The unit came with a charge controller which, from the instructions, it seems I dont need when charging a battery only when a controlled 12V is required - so I didnt use it.
Can I assume the diode is no good?
Could I have connected it up wrong?
Any idea how to check its working ok?

Thanks in advance
 

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Hi Twinky,
I'm not sure about your 13 watt panel but most of these small solar battery maintainers are just that.
They will maintain a battery unless there are any residual or parasitic loads and you have good sunlight most days.

They will not compensate for any continuous drain. After all the drain can be up to half an amp or 6 watts for 24 hours a day.

The best solution is to try and track down any such drain by putting an ammeter between the + post and lead. Seeing what current is continuously flowing and remove all automotive fuses until you find the offending circuit.

Mine was the radio and GPS.

Ray.
 

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twinky said:
Can I assume the diode is no good?
Maybe, but more likely the only diode is in the charge controller - which you didn't use?
twinky said:
Could I have connected it up wrong?
Yes
twinky said:
Any idea how to check its working ok?
Put a voltmeter across the output and shine a light on it.
 

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Discussion Starter · #5 ·
Thanks guys

A couple of points

1. The battery without the solar panel would hold charge for weeks without a problem.

2. The instructions show a diagram how to connect the panel up to a battery without using the charge controller - surely if the diode is in the controller only they would not show this?

3. I have a diode tester and have put it across the output of the panel. One way it shows 0V and the other it shows 1V. Does that prove the diode is in the panel and functioning correctly?

4. When I got the panel in moderate light ( not direct sunlight) it was showing 17V across the panel and 250mA. That I assume is pretty good.
 

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Is the socket you plugged the panel into live all the time?

I only ask as we cannot plug our panels into the dash socket as they are only live when the ignition is on, we have put other sockets in for the panels, one to the vehicle battery and one for the leisure battery.

Tina
 

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Discussion Starter · #7 ·
TinaGlenn said:
Is the socket you plugged the panel into live all the time?

I only ask as we cannot plug our panels into the dash socket as they are only live when the ignition is on, we have put other sockets in for the panels, one to the vehicle battery and one for the leisure battery.

Tina
Used croc clips straight onto battery
 
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