Emergency lighting. Power outages are all too commonplace in the Philippines. They can be a little scary at night when your own house goes dark along with the entire neighborhood. Like just about every resident of the Philippines, we have bought battery powered lamps and backup lights. These typically don’t throw off much light and don’t last long. We have a generator, but going out to the storage building (in the middle of the night, in the dark) and starting up is not so appealing, especially when the outage might end up being a short one. That would mean going back out to shutdown the generator and put it away.
Since we replaced all of our outdoor lights with LED bulbs, we got to thinking about using our existing lights rather than the assortment of backup lanterns we have bought over the years. Like most homeowners our house has various circuits for lighting and outlets. One of our circuits powers our outdoor lights. We thought, “could we supply backup power to those lights through an automatic battery backup system. Rising interest in solar power has resulted in a plethora of new gadgets. One that I found on aliexpress.com seem to combine an inverter which would convert 12V D.C. power from a lead-acid storage battery to 230 VAC to power our lights. The unit also has a built in automatic battery charger and a relay which switches to the backup battery when utility power goes out.
The connections are as follows. The heavy red and black connections between the battery and the inverter don’t really need a comment except to say that we bought the cables along with the inverter and are glad we did. If you look at the inverter you will see two connections. The gray cable above is to a 230V wall outlet. The brown connector connects the outdoor lighting circuit to the inverter. Basically we disconnected this lighting circuit from its breaker in the panel box and rerouted it (another story) to the inverter.
During normal operation, the inverter passes utility power to the lighting circuit. When there is a utility power outage, the lighting circuit is switched to power from the inverter/storage battery. Our outdoor lights were already on a timer so that the outdoor lights come on only at dusk and turn off at dawn.
The internet http://all-about-lead-acid-batteries.capnfatz.com/all-about-lead-acid-batteries/lead-acid-battery-fundamentals/amp-hours-vs-kilowatt-hours/ tells us that a 100 Amp Hour battery will power a 60W load for twenty hours. Our outdoor lighting load is a bit more than that, but if this information is correct we should have good emergency lighting throughout any night.
Cost: Inverter and cables about $135 including shipping. The battery P6,000.00. Link to buy the inverter https://www.aliexpress.com/item/2016-multifunction-power-inverter-12v-220v-inverter-UPS-function-12V-Battery-Charger-universal-socket-UK-plug/32600500908.html I have found the seller to be responsive to after-the-sale inquiries.
Another use for the system is to power a fan. Not having any breeze from a fan on a sweltering day is one of the particular tortures of the power outage. The unit could easily power a fan. If more capacity is needed or wanted, additional batteries can be added, linked in parallel.
None of this may be news to you but we post it in the hope that it will be useful to others. We gave the system a test by turning on the outdoor lights and disconnecting the utility power to the inverter. It worked perfectly. We ended our test arbitrarily at four hours, but certainly the lights would have stayed on longer.
UPDATE: August 12, 2017. Our backup system described above, worked fine for a few months. Then the Samlex inverter gave us warning messages about an input failure. This involved a warning light and a buzzer. We thought the battery had already gone bad and, with reluctance, we bought a new one. That did not solve the problem. We examined the Samlex instructions and noted that it said that it would not work with a system in which the neutral is bonded to ground in the panel box, as ours is. That does not explain why it worked fine for months.
We really don’t have an explanation for the problems with the Samlex. However I had a new brainstorm. I use so-called uninterruptable power supplies (UPS) for my main computer. This is practically a necessity in a place which has routine power outages. My first UPS was made by APC, the leader in UPS. Eventually the built in lead-acid battery wore out and I was unable to find a replacement battery locally. I eventually bought a new, larger APC UPS.