Emergency Power in the Philippines – 12 Volt DC Car Inverter


As with death and taxes, some things are inevitable in life, and if you live in the Philippines, you can add “brown outs” to that short list of sad realities.  Before going on, let’s map out a few definitions:  “Brown outs” in the Philippines for an area-wide loss of electrical power (blackouts).  Some brownouts are accidental with falling coconut trees cutting lines, itchy carabaoas (prehistoric cows) knocking over poles or China-sourced transformers suddenly giving up the ghost.  Other brownouts are planned, either for electric company workers to cut back encroaching jungle growth (shit grows FAST here) or to hopscotch power across a strained network that is long on demand and short on supply.  The latter usually happens in the ‘dry’ summer months when everyone is cranking up their aircon and the hydroelectric plants – which supply 20% of the electrical supply in the Philippines – are dealing with diminished output due to lack of rain.

As everyone knows, losing one’s power is a royal pain in the proverbial arse. No internet, TV and fans is bad enough, but the real challenge with brownouts  is NOT KNOWING how long it is going to last – will it be a short 10 minute hiccup or will it be the much longer multi-hour blackout. I am not alone among my expat kin in dreading brownouts. Coming from First World nations, we have been conditioned to constant, uninterrupted power.   By contrast, Filipinos seem to take brownouts in stride and make the most of it – which might account for continued surges in the national birth rate.

Beautiful Filipinas and darkness aside, brownouts are usually not a whole lot of fun.

Brownouts in our area (Dumaguete City, Negros Oriental) are not all that common.  A typical local loss will only run about 10 to 20 minutes with much rarer brownouts running three to four hours (ugh). In total, we might have six to eight 10 minute losses a month with one or two of the dreaded multi-hour brownouts tossed in. Compared to other areas of the Philippines, that’s actually not all that bad. But still.

My wife and I and I both work online, so we need out internet. A stop gap measure we put in place is an auto-switching Uninterruptable Power Supply (UPS) that can provide about 30 minutes of power to our fiber optic modem and router during a brownout.  Chichay and I also have IBM Thinkpad T440S laptops with dual extended batteries that can run for 5-8 hours on their own.  What I needed then, was something that could power the modem, router and a couple of fans should the power stay off for more than the 30 minute backup provided by the UPS. 

In looking for solutions, I considered four options: A traditional gas or diesel fuel generator, a ‘simple’ 48 volt (4 battery) solar array, a portable battery power packs or a 12 volt DC inverter that can provide 220 volt power from a car battery.  After a good deal of research and asking about, I finally settled on the DC inverter.  The reasons for this were pretty simple:

GENERATORS are great and can provide a great deal of power during multi-hour (or day!) power losses. The downsides are that they are noisy (my neighbor two houses down has a Honda genny and it’s pretty loud even from our house), expensive (a decent and reliable one will run over $500 USD) and the fuel has to be used regularly or replaced.  Add to this that brownouts are not a HUGE problem where we are at and a generator didn’t seem practical for our needs.

SOLAR ARRAY:  We actually had a big solar array in Dauin, but it only worked during the day as the systems batteries had lost most of their charging capacity.  Solar is great but it also comes with a number of downsides:  They are expensive and the batteries just don’t last, especially in a hot and humid environment such as the Philippines. I know two other people who have home solar arrays here and they both regret getting them due to the battery issue.  I will eventually get a solar-based system, but only when the battery issue is solved (looks like Tesla and a few other firms are coming out with ‘million mile batteries’ soon) and we actually own the house we are living in.

BATTERY-BASED GENERATOR:  These things look like small portable generators but they actually contain a number of Lithium Ion batteries.  Downsides on these again seem to be the cost versus the available power from the unit and how long the batteries will last before needing to be replaced.  So as with the generator or solar array, this idea was scratched off the list.


The idea behind this is pretty simple.  You buy a 12 volt DC inverter, hook it up to your car battery, start the car and plug whatever you need to power into the AC outputs on the inverter (usually through an extension cord).  It basically mimics what a generator does in terms of having engine-generated DC power converted into 220 volt alternating current.  Now, with that said, there are a few caveats:

ALTERNATOR: Vehicle alternators are not intended to provide long-term power.  Recreational vehicles have higher capacity alternators and dedicated 12 volt batteries for prolonged power generation and other vehicles have ‘high rev’ settings for when they are idling.  (Given that my truck doesn’t have a traditional throttle assembly, I am thinking the latter can be replicated with some sort of adjustable rod between the steering wheel and acceleration pedal to bring it up to 1,500 RPMs or so.)

IDLING: Running your vehicle while not under load can damage some parts over time.  (Hence the ‘high rev’ settings on some commercial vehicles.) Given that brownouts here are not that long and we are only looking for about 400 watts an hour of supply, I don’t think that will be an issue. Plus, my Tucson is a Common Rail diesel which apparently idles cleaner and with less wear than the older ‘dirty’ diesels.

WEATHER:  Inverters are not waterproof and given the need for it to be attached to the car battery by short leads, running the system during a tropical downpour will be a bit of a challenge.  Some folks mount their inverters under the seat of their car and run the extension cord out a lowered window fitted with ‘rain guards.’  My truck has rain guards so maybe this might be a solution.  My only reservation is having something that can explode under the seat – I’d need a way to safely keep one of the battery leads disconnected when it is not needed. 

I shopped around locally and online for my inverter.  The local stuff was in short supply and overpriced, so I had to settle on ordering one online.  What I wanted was a PURE SINE WAVE inverter with a claimed capacity of 3,000 watts or higher. Now this is important:  Pure sine wave inverters are more efficient and cleaner than cheaper MODIFIED SINE WAVE inverters.  Modified (or ‘hybrid’) wave inverters can also cause problems with motor-driven devices such as fans, microwaves and refrigerators and also delicate electronics such as phone chargers and computers.  The first inverter I ordered claimed to be PURE SINE but when I got it, the fan I plugged into it would surge while running.  It also wouldn’t power my microwave. Hence, it wasn’t a pure sine wave. Since I purchased it on Lazada, returning it wasn’t an issue.  The next pure sine inverter I purchased on Lazada passed all the tests I threw at it (fan, microwave, refrigerator and our new 1 HP inverter aircon), so I had to assume it was actually purse sine (or, as a subscriber suggested, just a really good modified wave).  I also purchased a 25 meter Showa extension cord system that can run from the inverter and into the house with minimal voltage drop.  The total cost for the 3,000 watt inverter and extension assembly was about $130 US dollars.

Although it hasn’t been put to the test yet, I am pretty confident with our system.  Although I tested it for 30 minutes on the 1 HP inverter aircon in our house, we won’t be using it for that – just the aforementioned modem, router and a few fans.  Now the only thing left to do is figure a way to ‘weatherize’ the system – I don’t really look forward to playing around with high-amp cables in the midst of a tropical deluge.  Or, if I can find a capable electrician, I just might mount it under the drivers seat.

I hope my personal experience with an emergency power supply has been helpful.  If you’ve had experiences with solar, generators or inverters, please feel free to leave them down in the comments sections.

Puppies, rainbows and unicorns to all.

For those who don’t want to read, you can see the video that I did on this subject HERE



  1. Hi Ned
    Following your post I’m interested in going down this route. Can you share the details of the make you returned that was not pure sine wave and the make you have now purchased. Thanks. Paul.

      1. Hi Ned. I worked out the model you bought from the pictures. Ordered the same but the Lazada order failed and cancelled. Ordered another model from Shopee..5000w. Bargain. All the specifications matched pure sine wave. When it arrived the manual said Modified type so returned. Just missed you the other Sunday as you were leaving Valencia as wanted to know how you are doing with yours before I think about ordering again. This Sunday will be a first big test I imagine. Paul.

Leave a Reply

Your email address will not be published. Required fields are marked *