Solar-powered garden lights indoors?

[JohnW2]

my thoughts are the light source at or near the window will be perhaps 5 times the value so look similar to a say 6w room centre light source where 1.5w will go away to the back wall and perhaps 3w sideways and perhaps 1.5w forward so a .3w will replicate a 6w equivalent room central light at the window??

You may be right - I need to do some experiments.

However, I suspect that if the light source is near the window (and pointing at it), the appearance from outside might be very 'unnatural', hence perhaps not a very convincing indicator that the house is probably occupied - but we'll see!

Kind Regards,m John

 

[big-all]

You may be right - I need to do some experiments.

However, I suspect that if the light source is near the window (and pointing at it), the appearance from outside might be very 'unnatural', hence perhaps not a very convincing indicator that the house is probably occupied - but we'll see!

Kind Regards,m John

indeed i love experiments and i tend to share the mostly "pointless to most" results as iff even one person gains from the information it has a value

 

[JohnW2]

indeed i love experiments and i tend to share the mostly "pointless to most" results as iff even one person gains from the information it has a value

I totally agree = and one thing than many people seem to overlook is that 'negative' (or even just 'neutral') results of experiments can be just as important/valuable to some people as are 'positive' results.

In fields I work in professionally (and I'm sure many others), those who conduct research which yields results which are not 'positive' often struggle in their attempts to share that information with those to whom it might be of interest - since journal editors and organisers of meetings/conferences have traditionally been less prepared to accept papers/presentations of research findings which are not ';positive'. That situation has improved in more recent times but, at least in my opinion, there is still a way to go!

If/when I do the experiments I mentioned, I will certainly report back - and regardless of what the results are

Kind Regards, John

 

[ericmark]

Over my time I have seen the changes in methods used to charge caravan batteries. It was around the late 60's early 70's first got involved, this is the time of the Lucas ACR alternator and a firm called Durite who are still around today made a replacement rectifier with 9 of the same sized diodes, so I used three extra diodes to the field and used the three in the rectifier as a second output, this charged the second battery for a caravan far better than the proprietary methods with blocking diodes and relays.

I found the 0.6 volt drop with the blocking diode resulted in both batteries not being fully charged, OK with marine applications where the 440 regulator had Hi, Med, Lo terminals but not with the built in regulator of the ACR alternator. The relay did work, but the vehicle battery had less cable to it to the caravan battery.

Until the DC to DC inverter hit the market, there was no really successful method of charging the second battery, the second battery needed stage charging to have any hope of fully recharging it, and even with stage charging it would take 12 hours and we tend not to tow caravans for 12 hours.

Even the canal boats had problems without stage charging, and they could easy run 8 hours.

The solar panels had the same problem, the MPPT controller however does help, the major problem with a stage charger is the load can stop the stage charger dropping into the final stage, so can over charge the battery. But also with the old solar control (a simple zenor diode) morning and evening output was very low, the method around this was to vary the solar panels output voltage, so as to gain the most output, but to charge a battery the ideal voltage is not the same as the ideal voltage output of the solar panel, so an inverter is used so the panel voltage have vary through the day, but battery voltage stays constant.

Clearly the inverter uses some power, so this is only done with the larger panels.

Deep cycling lead acid means a long recharge time, put a energy monitor on a mobility scooter battery and before fully recharged from flat again it takes around 8 hours, and this is when put on charge as soon as the scooter returns home, and with AGM batteries, if batteries left a few days, then 12 hours again.

To get around the time it takes to recharge lead acid the narrow boat users look at using a hook up once a month to fully recharge the battery, and with your situation you would likely need two lead acid batteries and alternate them so each month they can be fully recharged.

So in essence all the solar panels are doing is reducing the size of lead acid required.

We do have the alkaline battery, started with the Nickel Iron, these can charge and discharge faster, today we have the Li-ion battery, again able to charge and discharge faster, and most the garden solar lights have AA cells in them, the charge control is often built into the cell, and these can recharge in 12 hours. But at the moment around 8:30 am to 3:50 pm looking at my solar panels so around 7 hours max. Just when I need lighting on my drive, the sun light has dropped to a level where not going to recharge the battery.

So assuming using lead acid then all the solar does is extend the time between needing to swap the battery and take it to be recharged. Or at least swap which is being used as well as being charged, but that means manually swapping batteries, so if the battery needs swapping anyway, is there any gain using solar?

 

[Harry Bloomfield]

I have removed most the PIR outside lights, can't see why I should make it safe for intruders, let them trip over rubbish in the garden, and seeing a torch in a house is more likely to raise the alarm to when one can roam around using provided lighting.

We were lucky we were not broken into, it was a worry when looking after my mother as insurance would not cover if left I think for more than 3 weeks unoccupied. But we never turned the power off, heating set low, and no lights switched on, we had never intended leaving it unoccupied for a couple of years, we moved in with mother so she could be released from hospital, we had not intended it to be long term.

We've never had any such problems. I used to, from the 80's, when we were away - set timers, in rooms, to switch lights on and off, likewise a dusk to 11 drive lighting. We do nowt much different now, just switch things via smart switches. We also let the neighbours opposite, know we will be away, when back, and about the lighting going on and off.

The place is only really vulnerable from the front, no one in their right mind would even attempt to approach from any other direction.

 

[Harry Bloomfield]

Over my time I have seen the changes in methods used to charge caravan batteries. It was around the late 60's early 70's first got involved, this is the time of the Lucas ACR alternator and a firm called Durite who are still around today made a replacement rectifier with 9 of the same sized diodes, so I used three extra diodes to the field and used the three in the rectifier as a second output, this charged the second battery for a caravan far better than the proprietary methods with blocking diodes and relays.

Diodes in the charge circuit, were always a no, no. W/L controlled relays and later the voltage controlled relays, always worked fine for me. the secret was one of installing an adequate size of cable, to overcome the volts drop along the length. Not many installing such cables, understand volts drop, or take account of it.

 

[ericmark]

Marine installations with CAV 440 regulators worked OK, that's the 440 with hi med lo not seen split charging using 440 with M1 and M2 termials across the resistor. CAV 208 alternator if I remember right, one of very few alternators with current control.

But back then the battery in a caravan did so little, lighting was gas. Water pumps foot operated, no central heating fans, etc. Today the battery in a caravan is so important not longer will split charging relays do.

 

[Harry Bloomfield]

Today the battery in a caravan is so important not longer will split charging relays do.

They work absolutely fine, providing the path from alternator, to the caravan's battery, has a low enough resistance.

 

[big-all]

my thoughts are the light source at or near the window will be perhaps 5 times the value so look similar to a say 6w room centre light source where 1.5w will go away to the back wall and perhaps 3w sideways and perhaps 1.5w forward so a .3w will replicate a 6w equivalent room central light at the window??
i will tomorrow try my newest fully charged 5ah battey but please dont expect a result for at least 10 day continuous trial

though i would update this post
i was quite disappointed not by the longevity but the way ryobi do there calculations and rate there led lamps
i have several ryobi lamps and they conveniently have a watts consumed but wrongly in my opinion quote the minimum draw only
they also do no more than a maths equation which is wrong on so many levels as in transmission /conversion losses 'battery diminishing capacity due to heat or cold and age plus the fact you cannot flatten a lion battery so perhaps 5 or so % is not available so perhaps 10-15% overstated in general

 

[JohnW2]

Hi, does anyone know how well (if at all!) 'solar-powered garden lights' (lights on continuously during hours of darkness, not PIR-controlled) would get charged if sited indoors, close to a window?
I ask because I am considering ways of achieving some nocturnal lighting (for 'security') in a house which is sometimes unoccupied for appreciable periods with the whole electrical installation switched off.

Some of you may recall when I started this thread, with the above question, last year. Most people (including myself) were fairly doubtful as to whether it was a viable idea.

Some 8 months on, I have at least got around to conducting a preliminary experiment, and the results make me abit more optimistic, at least during the summer months ...

I invested £1.50 in a diddy "solar garden light" from PoundLand. It has a coupleof little LEDs, a tiny 'solar panel' (about 30mm squatre) and an equally tiny battery (1.2V 40 mAh).

For the past couple of weeks or so, I've had it sitting indoors on a windowsill, pointing at a West-facing window through a net curtain. Every night at dusk (pretty 'late dusk') the LEDs come on very brightly (I imagine 'as bright as is intended). Depending upon how much sun there has been, the LEDs remain pretty bright for at least 3-4 hours, sometimes appreciably longer, and then gradually start to 'fade'. I've never been up late enough to see them 'fade to nothing', and they have invariably been switched off by sunlight by the time I get up. The same then happens the next day, and subsequent days, the battery clearly getting charged up enough during the (currently long) hours of daylight for the LEDs to be bright when they come on.

If that can be achieved with a tiny solar panel and battery, and a couple of diddy LEDs, I suspect that an appreciably more 'substantial' unit wiould before quite well, at least during summer. It remains to be seen whether I could get enough charging dine to be useful during the short days of Winter!

Kind Regards, John

 

[Harry Bloomfield]

If that can be achieved with a tiny solar panel and battery, and a couple of diddy LEDs, I suspect that an appreciably more 'substantial' unit wiould before quite well, at least during summer. It remains to be seen whether I could get enough charging dine to be useful during the short days of Winter!

Avril is rather attracted to lots of decorative solar lights in the garden, and what I notice with the most recent offerings is....

They seem to intelligently control when they power the LED. If the battery is running a bit low, they don't turn on. Besides which, they no longer run the LED, until the battery is flat, rather they switch off at some point before it becomes flat, thus avoiding damaging the battery.

 

[foxhole]

Lots of solar lights with separate wired panels allowing you to put solar panel out side while using dusk to dawn lighting internally .

 

[JohnW2]

Avril is rather attracted to lots of decorative solar lights in the garden, and what I notice with the most recent offerings is.... They seem to intelligently control when they power the LED. If the battery is running a bit low, they don't turn on. Besides which, they no longer run the LED, until the battery is flat, rather they switch off at some point before it becomes flat, thus avoiding damaging the battery.

Interesting. Mine seem to have always been coming on when it gets 'properly dark' (later than what I would normally describe as 'dusk'). However, as I said, I don't know when they've 'gone off', either because they have 'faded to non-existence' or because they have switched themselves off - they've always till be on, even if getting dimmer, at the time I've gone to bed.

 

[JohnW2]

Lots of solar lights with separate wired panels allowing you to put solar panel out side while using dusk to dawn lighting internally .

Indeed - that was the 'Plan B' that I was thinking I would have to adopt. The experiments I need to do next are to determine the relative amount of charging achieved with indoor and outdoor panels.

 

[SUNRAY]

Some of you may recall when I started this thread, with the above question, last year. Most people (including myself) were fairly doubtful as to whether it was a viable idea.

Some 8 months on, I have at least got around to conducting a preliminary experiment, and the results make me abit more optimistic, at least during the summer months ...

I invested £1.50 in a diddy "solar garden light" from PoundLand. It has a coupleof little LEDs, a tiny 'solar panel' (about 30mm squatre) and an equally tiny battery (1.2V 40 mAh).

For the past couple of weeks or so, I've had it sitting indoors on a windowsill, pointing at a West-facing window through a net curtain. Every night at dusk (pretty 'late dusk') the LEDs come on very brightly (I imagine 'as bright as is intended). Depending upon how much sun there has been, the LEDs remain pretty bright for at least 3-4 hours, sometimes appreciably longer, and then gradually start to 'fade'. I've never been up late enough to see them 'fade to nothing', and they have invariably been switched off by sunlight by the time I get up. The same then happens the next day, and subsequent days, the battery clearly getting charged up enough during the (currently long) hours of daylight for the LEDs to be bright when they come on.

If that can be achieved with a tiny solar panel and battery, and a couple of diddy LEDs, I suspect that an appreciably more 'substantial' unit wiould before quite well, at least during summer. It remains to be seen whether I could get enough charging dine to be useful during the short days of Winter!

View attachment 349259

Kind Regards, John

Corr 2 weeks and still doing 3 hours a day, you must have picked up a good one!