i have one they are ok to stop the battery from going flat when left for any length of time thats about all.has anyone used a solar power trickle charger, I see Maplins sell one for around a tenner. Do they do the job?. Unfortunately I have to lay the van up for the winter something Ive never had to do before so advice please.....
has anyone used a solar power trickle charger, I see Maplins sell one for around a tenner. Do they do the job?. Unfortunately I have to lay the van up for the winter something Ive never had to do before so advice please.....
not wanting to sound off or the like ,but if the battery is left disconected,then what about your alarm, imobiliser and if the van has a coded imobiliser then there is a good chance it will lose its code. then a trip to main dealers to be put on the computer and at there prices !!!!!!!!!!!! i know the renault safrane i had warned of such .
I have read through this thread with great interest and although Slim has obviously made his mind up, I suspect from his responses that he had before starting the thread, I thought I would post a few figures for anyone who may be interested.
These panels are unregulated, therefore the maximum output voltage, i.e. when directly facing strong sun, for safety reasons can be no more than about 15V. Any more and serious damage could be caused to the vehicle electronics.
With all photovoltaic cells both the voltage and the current are proportional to the amount of light recieved.
To maintain charge in a charged battery an input voltage of approx 14V+ is required. So although you are quite correct in stateing that these panels produce power even on cloudy days, it requires quite bright light to raise the output voltage to 14V+, and provide "usefull" power.
The maximum output of the discused panel is 1.5W equal to 0.1A at 15V, yes 1/10 of an amp (100ma) maximum output, as the conditions are rarely perfect a generous figure in a british winter would be for 1/2 max for 5hrs per day. 0.05 X 5 = 0.25AH per day, with battery inefficiences this would equate to approx 0.2AH of battery loss.
Natural discharge of lead acid batteries vairies with age, a brand new (never used) battery should loose no more than 0.1% per day, a well used but servicable battery will loose 1% per day. Assuming a 100AH battery and taking a mid figure this is around 0.5AH, or double the best you are likely to get from the panel.
The fact is that most vehicles are over batteried and if there are no other problems and the battery is reasonably good, restarting after 4-6 weeks of inactivity should not present a problem, even with no external topup.
Unfortunatly the output from these panels is so small that the extra "storage time" they allow is very small.
I would also like to point out that the panel of Gary's has almost 4 times the output and therefore rather more usefull.
To end on a humourous note, I did here a story of a man who had one of these type of panels in his car as he only used it on weekends. He very dilligently set it up each week ensuring it was properly pluged into his cigar lighter. After several months use he is totaly convinced of the benefits, until someone pointed out that on his car (like most) for safety reasons the ciger lighter is ignition controled and not conected to the battery when parked, in fact he had never had his panel actualy connected
I had a 5watt trickle charge that does the job and it works when cloudy.Made by exide about 18 inches square ,with a long lead with croc clips, so can be moved around to best effect.If you go to big you will surely need a voltage regulator.My mate has one as well, if intrested a tenner plus post,can put photo on if you want a look.Selling because both have new vans,hardly been used.
I have read through this thread with great interest and although Slim has obviously made his mind up, I suspect from his responses that he had before starting the thread, I thought I would post a few figures for anyone who may be interested.
These panels are unregulated, therefore the maximum output voltage, i.e. when directly facing strong sun, for safety reasons can be no more than about 15V. Any more and serious damage could be caused to the vehicle electronics.
With all photovoltaic cells both the voltage and the current are proportional to the amount of light recieved.
To maintain charge in a charged battery an input voltage of approx 14V+ is required. So although you are quite correct in stateing that these panels produce power even on cloudy days, it requires quite bright light to raise the output voltage to 14V+, and provide "usefull" power.
The maximum output of the discused panel is 1.5W equal to 0.1A at 15V, yes 1/10 of an amp (100ma) maximum output, as the conditions are rarely perfect a generous figure in a british winter would be for 1/2 max for 5hrs per day. 0.05 X 5 = 0.25AH per day, with battery inefficiences this would equate to approx 0.2AH of battery loss.
Natural discharge of lead acid batteries vairies with age, a brand new (never used) battery should loose no more than 0.1% per day, a well used but servicable battery will loose 1% per day. Assuming a 100AH battery and taking a mid figure this is around 0.5AH, or double the best you are likely to get from the panel.
The fact is that most vehicles are over batteried and if there are no other problems and the battery is reasonably good, restarting after 4-6 weeks of inactivity should not present a problem, even with no external topup.
Unfortunatly the output from these panels is so small that the extra "storage time" they allow is very small.
I would also like to point out that the panel of Gary's has almost 4 times the output and therefore rather more usefull.
To end on a humourous note, I did here a story of a man who had one of these type of panels in his car as he only used it on weekends. He very dilligently set it up each week ensuring it was properly pluged into his cigar lighter. After several months use he is totaly convinced of the benefits, until someone pointed out that on his car (like most) for safety reasons the ciger lighter is ignition controled and not conected to the battery when parked, in fact he had never had his panel actualy connected