solar panels to keep battery topped up?

groups.google.com/advanced_search B-)

I've got the =A320ish 1.5W Maplin jobbie attached to the generator to ke= ep it topped up I'll only know that it hasn't done that in a couple of year= s time in a power cut.

It would do a better job if it didn't have a stupid flashing LED. Monitoring the output voltage when the LED is on there is naff all voltage, LED off just enough to put a tiddle into the battery. As the LE= D has a rough 50% duty cycle, 50% of the gathered power is wasted...

The Carlisle store had a bigger panel(s, might have had two or three) in= their clearance heap on Thursday last week at =A399ish about =A320 off n= ot sure of the power but the box was about 4' x 1' so maybe the 18W one? Th= at would fit the price as well.

I have a six watt panel that keeps my tractor battery topped up, seems to work well. My boat has a pair of forty watt panels on the top of the wheelhouse. Both seem to work well.

John

I had a search round. The above appears to be the same as this one, at half the price. I'll get it ordered.

Hi, it was me who asked the same question a few months ago. In the end I bought ebay item 140181679436 - I decided to buy the most powerful I could justify etc. so far it seems to work well even inside a car port (made from polytunnel plastic) in the middle of winter up here in NW Scotland. The LR (V8) was left standing unused for 2 months and it started no problem. Can't say of course if this was down to the solar panel or not, but I think it helped, previously I always had problems starting. No connection with seller etc etc.

Andrew

Take care - there's no spec that I could see, what is the rating??

Andrew

For what it's worth, follow the picture reference back to Maplin, & you get here:-

I have one, it works a treat on the P38. Cost £10 off ebay.

John Williamson wibbled

... and I thought Maplins was pretty good. ;)

For anybody using the maplins ones - me and a mate both have them in our motors too.

I have only ever seen the blue light flashing - but he managed to find some sun in the summer and says that in proper sun it comes on solidly!.

Which makes me assume that they very little charging unless its proper sunny..

Time for the wire cutters I think. Mine will never see full sun as the garage is on the north side of the house.

If the circuitry is real, rather than a bit of silicon under a lump of resin, some adjustment of the flashing rate and duty cycle might be in order. A short flash every 30s would be more than enough as a "confidence" indicator.

Dave Liquorice wibbled

Being an electrical numpty (yes, I mean me, not you!) is it likely that one could just cut the led out and release the latent, humongous, extra power available?

Or (more likely I suspect) would one have to resort to soldering another wire in to bridge the gap?

Despite being a numpty, I raced model cars to European levels and can handle a soldering iron and follow instructions down to a very small level, track re-building for instance. I just don't know what most components actually 'do' for the circuits I butcher ... ;)

Mind, if you can work out how to change the duty cycle and post the info back here I'd be obliged, as it does sound a bit more of an elegant solution than hacking the led out ... ;)

In message , Jonathan Spencer (that's me) writes

They arrived today, for £24.93 delivered. Look pretty neat. Weatherproof. Can be wall-mounted using two screws, or stuck on the inside of a windscreen using the supplied suckers. The cable is 2.75m long. Using the supplied crocodile clips, I could connect them in parallel to provide 3w charge. But I'll put one on my boat and the other on the old tractor, I mean, Land-Rover.

The suckers dont suck enough and it will fall off!. Mine is now (almost) mounted on a bit of scrap ally which clips/wedges infront of my passenger windscreen.

Where does it say it is weatherproof? Im sure that the identical looking maplin one i have says it isnt weatherproof! (else id just stick it outside on the roof!)

Good point. I had been looking at lots of them, many for permanently fitting to boats. They are not only weatherproof but can handle salt water. I'd obviously mixed them up with this unit.

Here is Maplin's (potentially confusing) FAQ:

Q) Is the unit waterproof and suitable for fitting to a garage roof to trickle charge a car inside? - Ian

A) Yes, but it is not waterproof.

So it can be externally mounted, water will get in, but it shouldn't harm the unit. Hmmm.

I've emailed sailgb for clarification.