Outdoor security cameras from companies including Swann,
Nest, Arlo, Ring, Reolink, Uniden and many others are becoming a fixture in more
homes – or should be. Solar panel chargers are seen as the solution to the
annoyance of constant battery recharging.
Spoiler alert – only one of the solar panel chargers on test, was capable of producing enough power to keep the camera running and charge the battery at the same time! Read on.
Solar Panel chargers 101
Before we get into Solar Panel chargers it is important to know
that it is not necessarily physical size but energy efficiency that counts.
Panels/cells can be either thin crystal (cheapest), polycrystal/amorphous (mid-price) or monocrystal silicon (more expensive). Efficiencies in converting sunshine to power range up to 10, 19.3 and 24.2% respectively.
Gadget Guy found popular security-camera portable solar panel chargers range from a meagre 12-cells, 24-cells (average) to a massive 64. Assuming each cell generates similar current (amperage) the more cells the better.
But of the five panels tested the worst had 10% efficiency and the best was 17% indicating not very efficient cells, placement or power delivery.
Then there is the IC chip controlling voltage and amperage output. Because all the panels only have to power a known camera with set battery/voltage/mAh, the IC regulator is the cheapest possible to do the job – just delivering up to the stated voltage/average. In multimeter tests, two had no semblance of regulated voltage delivering from below 1V to 9V (but read why later*)
Mounting solar panel chargers
Roof-mounted solar panels work best in an east/west orientation (north facing) where the sunlight hits at a 90º angle.
The ideal tilt for Australian sun is at 32º from horizontal (imagine 1/3rd of a right-angle). Anything more or less reduces efficiency far too much. Security camera solar panel chargers are no different!
Why then do the majority of photographs show almost vertically mounted panels under eaves or on walls facing a fixed direction?
This orientation would produce effectively less than half of the efficiency of our test rig.
How much voltage and amperage do you need?
The assumption most panel suppliers make is that the camera has a ‘few’ activations per day. We dug deeper to find what each camera maker defined as a few and what power the cameras actually need.
Only Uniden was brave enough to state,
“The panel allows the camera to recharge during daylight conditions. Different weather conditions in Australia and New Zealand can affect the rate of charge to the battery.”
Uniden state about six month’s battery life – at one detection a day! That is unrealistic but it does add that the battery (on a specific model) will last a total of 650 minutes (day use) and 400 minutes for night use. It goes on, “Fully charge the camera with a wall charger first and only use the Solar Panel for long-term power. Heavy usage of your camera can drain the battery faster than the Solar panel can recharge it.”
We estimate that a camera will have at least six activations per day resulting in live streaming and recording to the cloud or a local microSD card. Using Uniden as a guide that is about a month or so’s battery life as evidenced by frequent customer reviews of all cameras. Fact: you won’t get anywhere near the claimed battery life.
How much does current does a camera really draw?
In idle mode it should draw just enough current to keep a
PIR detector and Wi-Fi alive. We could only measure the battery depletion because
these are sealed units and no maker reveals this statistic.
Working backwards we estimate a typical camera with IR and PIR needs about 5V/.8A (4W) to run the device and maintain the battery charge, let alone top it up. Our figures could be wrong so if any camera maker wants to reveal their power use we will be glad to publish it.
So, a solar panel charger with less than 4W (5V/.8A) will at best only slow the rate of battery depletion.
If you factor in cloudy days and inadequate placement to maximise the sun, then solar panels are not the panacea as typically quoted “for a continuous charge, so you’ll never run out of power”.
Electricity behaves predictably – volts x amps = watts. One
amp = 1000mA. And mAh is milliamp per hour.
So, a 5V battery capacity of 5,000mAh can provide 5A (25W) of power for one hour, 2.5A (12.5W) for two hours, 1.25A (6.25W) for three hours, and 500mA (2.5W) for 10 hours etc.
To put this in perspective a typical security camera battery is around 500mAh and if it lasts say, 1 hours (60 minutes) under load the maximum draw is 500mAh. Put in layman’s terms unless you can put in more power than the camera uses, the battery will have to make up the rest.
And finally, the fiddle factor – charging is not 100% efficient. For example, using a cheap regulator can mean an efficiency loss of up to 50%, usually via heat. That is where a quality USB Power regulation chip comes in.
We test this via a multimeter placed between the micro-USB connector and the battery. It measures voltage and amperage but there is one caveat. It works well with the standard USB power delivery 1.0 (5V/up to 5A) measuring a reasonably fixed voltage and variable amperage. We are not sure the results are accurate with Quick Charge 2.0 where voltage can vary from 3 to 9V.*
Review: Solar Panel Chargers – for security cameras
We conducted a 45-day test of the Swann, Ring, Arlo, Reolink
and Uniden panels. Rather than check daily we only need to know two things – how
much charge remains in the battery at the end of the trial and an estimate of the
efficiency of the panel.
Each fully charged camera and solar panel was set up together
on the same mounting board in the same position with direct sunlight (east to west)
available all day. The test period was December to mid- January where it was
cloudy for at least 15 (1/3rd) of those days.
Swann Solar Security Panel $94.95
The Swann Solar Security Panel cells measure 210 x 160m (33.6mm2) or about twice the size of the rest of the tested panels – although it is not too big to use. It has a proprietary two-pin water-resistant connector to the panel and a 3m cable ending in Micro-USB. Swann supplies a spare silicon cap for its camera to provide water resistance. It was tested with a Swann SWWHD-INTCAM.
It has a mammoth 80 standard-sized cells and outputs a ‘mostly’ regulated 5V/1A (5W) – voltage remains constant but amperage can vary. It uses a standard tripod mount that offers flexibility in positioning.
In the trial it was able to keep the battery fully charged – it produces more charge than the camera needs.
On further tests with a 0% charge battery and standard
camera activity it topped up the battery at about 5-10% per day, after 7-days
it had reached 58%.
Pro: True 5V output, Will keep the battery topped up, good price/performance Con: 2x larger than most panels
Ring Solar Panel $79
The Ring Solar Panel has 40-cells and outputs what appears to be unregulated* 5.2V/.42A (2.2W) where voltage can vary from 0-9V. It has a long 3.96m cable with a fixed cable connection to a proprietary barrel connector for its Stickup Cam. Note the Spotlight Cam below draws more power as the PIR is linked to LED spotlight – results are worse than the Stickup Cam.
We were a little overwhelmed by the marketing hype until we remembered that it is an Amazon Company focusing on one thing – the sale! Terms like ‘Non-stop charge’ (what about the night?), around the clock power with just a few hours of sunlight every day gives you 24/7 protection. The Solar Panel can keep your Spotlight Cam Battery charged with just a few hours of direct sunlight per day … It is all bovine excretement.
Over 45 days the battery went from 100% to 13%. This also
had a very poor mount bracket with only tilt (no swivel) adjustment so in normal
use sunlight efficiency is poor.
It was unable to charge the battery from 0% providing just enough power for the camera although it was not stable power resulting in dropouts and longer Wi-Fi connect times especially if the spotlight activated.
As it is built for Ring products and uses a proprietary connector there is no alternative. One ‘verified’ reader comment sums it up, “With regular motion events this panel cannot keep up with Ring’s charging demands. Its claims of ‘just a few hours of sun’ are grossly exaggerated.”
Pro: Only charger you can use for Ring Con: Does not live up to marketing hype and at best extend the manual recharge period by about 10-20%
The panel also works with any ‘box’ battery camera like the Arlo Go LTE camera with 7.2V/3.36A (26.35W) rated for up to 660 minutes of daylight use. The LTE uses more power because of 4G connection and results would have been worse.
But hang on, electricity behaves predictably and Arlo’s panel specifications do not make sense – a charger should provide higher wattage than the battery needs to charge – or it’s much, much slower to charge.
It has half the surface panel area of the Swann and a far shorter 1.8m cable (proprietary to micro-USB). Its voltage output appears unregulated* often providing less than 1V and sometimes more than 9V. But a battery won’t charge if the voltage is below 5V so go figure that!
In any case, the batteries are 7.2V requiring 17.57W (26.35W for LTE) or more to charge and our results confirm that under normal conditions the panel is simply not up to the task.
In our tests, the Arlo panel was able to provide enough power to run the Arlo camera but not reliably. It is insufficient to ever charge a battery 0-100%, especially during cloudy conditions. In the 45-day trials the with minimal camera use there was 5% left.
There are quite a lot of negative user reviews about this
panel. Typically, “This solar panel does not put out enough juice to make a
difference. In standby mode it might put out enough to power the camera without
losing too much. In live mode the camera depletes almost as rapidly as if it
were not there. Don’t waste your money.”
As such GadgetGuy cannot recommend it. Pro: none Con: Most expensive and worst performance
Reolink state that the camera should use a 5V/2A adaptor (10W) but will charge at voltages from 5-9V/1A. It also honestly states that the panel may not be able to keep the camera fully charged on days that are snowy, cloudy, gloomy, or rainy or periods of heavy use (active access or frequent triggers). At least it is honest.
In the 45-day trials the with minimal camera use and a fully
charged battery there was 47% left.
Pro: Cheapest of them all, will extend manual recharge intervals by about 2x, slightly better voltage regulation, includes extension cable Con: None really
Uniden Guardian solar panel $79
The Uniden Guardian Solar panel is exactly the same as the Reolink panel with the same specifications and cable. It fits all Reolink cameras as well as Uniden. Not surprisingly as the latter has the same pedigree as many Reolink cameras. The test was with a Uniden Guardian app cam Solo+.
In our test, the Reolink/Uniden performed second best after the Swann – still not powerful enough to produce more wattage to fully charge but it should reduce battery recharges by a factor of two.
Now you can see why we went to so much trouble over so long
The Swann solar panel charger in conjunction with the Swann 1080p Wi-Fi camera gets our recommendation as a panel that will at least provide enough power to run the camera and some excess to charge the battery. Its marketing hype is not over the top – “Mount the solar panel outdoors and forget about recharging the camera ever again” is truthful provided it has unimpeded east/west orientation and there are not extended periods of cloud cover.
As it supports standard USB 5V/1A you could buy this to support any camera (or other device) that uses standard USB charging like the Reolink or Uniden but you would need to jury-rig some waterproofing around the USB connection.
Reolink/Uniden (and their respective cameras) will give you at least a 2x extension on manual recharging – perhaps more if ideally sited and in good weather. These have the hooded micro-USB connector for weatherproofing.
Arlo and Amazon are overhyped and underperformers outputting
variable voltage and amperage*. But as these are proprietary chargers you have
no option if you wish to use these brands.
As we stated earlier things like the number of PIR events, Wi-Fi strength and recording/viewing time daily all affect battery life. As yet no battery-operated outdoor security camera lives up to claimed battery life but hey, they quote laboratory, not real-world tests.
And in Arlo and Ring’s case, it is time a third-party made a Quick Charge compatible, high-efficiency solar panel with a gimbal motorised mount to follow the sun – they would make a mint at even half of Arlo’s price! Perhaps we need this on our roof?