Electrical Emergency Battery Backup System for TV/Internet During Power Outages

[rsk]

I spent a year working in Kathmandu. Power outages were not only common there, they were programmed because the grid can't cope with the demand. Load shedding they call it, and they published a timetable showing which areas of the city would have power at which times of day.

Anyway, people there use inverters as back up. They're big ugly things but they work to run small loads such as lighting, tv, router etc. I found I could run my little electric Baletti coffee maker off it, but it growled at me in protest (worth the risk for the few minutes it takes to brew coffee).

As I understand it, things have improved and load shedding is needed far less frequently now - only if in dry season there's not enough water to power the hydro-electrics.

 

[dlgoff]

We use batteryuniversity.com as the vendor-independent source for reliable and comprehensive information about batteries.

And a good source it is.

 

[bob012345]

Yes. I'm a bit confused about that microwave oven thing of this topic too. To have the necessary capacity and power due a few minutes of excess load is not really a good solution by my book.

Regarding those torches - there are already flashlights with Li-ion battery and USB connector. They can cut back material consumption (batteries) some really nicely.

The system I envision to run the TV/internet for many hours would also power the microwave for a few minutes without much loss. It would have more than a kwh of energy so I might use ~8% to cook. I would hook it up to the microwave, cook dinner, then hook it to the TV and eat. The point was to retain normalcy.

As far as flashlights (torches), they are backup to my normal looking battery powered room lamps.

 

[rsk]

Attached photo is a load-shedding timetable from Kathmandu. This is from early 2016, the times slots shown are times when power is off. This was a particularly bad year, with general electricity problems exacerbated by a dispute over a new constitution which meant a blockade on the border with India, so very little getting through. Fuel, both for transport and the bottled kind used for heating and cooking, was especially badly affected.

 

[Rive]

I was thinking that people with electric cars have a significant amount of stored energy. If your daily timetable would support it, that could be a useful band aid.

I've been mulling over this for a time, and it's a strange problem. If the length of power outage cannot be planned, then this may easily end with temporally limited mobility. Would be really inconvenient.

On the other hand, what about hybrid vehicles? They have fuel tank (enormous capacity!) and can charge the battery (can they charge the battery without moving?).
I see more possibilities in PHEVs than in EVs (not right now, but for a possible future utilization).

 

[sophiecentaur]

Would be really inconvenient.

It could turn out to be something to expect - as it is these days in many parts of the World. You have to choose how big your reserve of energy should be (what can you afford?) on the basis of forecasts and experience.
This is where a pile of logs can be reassuring for people with some land and some say in what they can use in the home. For someone in multiple occupancy blocks, they would need to 'persuade' landlords to provide some form of local backup.

 

[Grinkle]

what about hybrid vehicles?

In general, one can idle the engine of any carbon-fuel car and draw power from the 12V rail, hybrid or otherwise. This rail is easily accessible via the cigarette lighter socket (I'm old enough to remember when it was still used as such). I just did a little reading on hybrid vehicles and as-constructed they are not different for this application than non-hybrid vehicles. Hybrid's also come with a traditional 12V auto battery for starting the engine and providing some reserve power for the 12V rail - they are kept charged by the alternator just as in gas only vehicles. The power-train-assist battery is higher voltage and not connected to the 12V rail of the hybrid vehicle. I suspect DIY'ing to tap into this battery for powering external devices would be the quickest way possible to void the warranty on the battery, and maybe on the vehicle as a whole, but I don't know that for sure, I am speculating there.

Edit -

I don't know if the power-train-assist battery will spin the alternator in a hybrid vehicle - if it will, then that storage is also available without necessarily idling the engine. I tried some quick searching and couldn't locate any reference to that question. I tend to doubt it, seems like a lot of added complexity for no real utility but I don't know for sure.

 

[sophiecentaur]

I suspect DIY'ing to tap into this battery for powering external devices would be the quickest way possible to void the warranty on the battery,

DIY yes but I did hear of a serious suggestion that electric car batteries could be used as off-peak storage. It makes you wonder how people would deal with that sort of a regime. It could involve deliberately under-using an electric car, just to use it as storage. Not good economy though; driving around with what would effectively be extra weight on board. Best to keep the batteries at home.

 

[Grinkle]

electric car batteries could be used as off-peak storage

IMO they are used that way, that is the point of charging overnight. The use of the stored energy is limited to transportation, obviously, at least afaik. Here is something I just found when I searched for "do tesla cars come with an inverter".

https://electrek.co/2021/02/23/tesl...wer-your-home-with-electric-car-battery-pack/

 

[Rive]

In general, one can idle the engine of any carbon-fuel car and draw power from the 12V rail

That just does not worth the effort.

If anything like this would happen then it would be about the main battery of an EV or PHEV, and it would be through a bidirectional charge/inverter circuit. And charging from the ICE would be through the drive train.
This tech is just not used (though possible and pieces of it exist already). It is a possibility we might think about.

 

[Grinkle]

That just does not worth the effort.

I have found RV-experience-based anecdotal references that fuel consumption for a Diesel engine to generate power is not much impacted by whether the engine is an auto engine or a dedicated generator engine, although I have not been able to find data to support that. I heard it swagged at 20% fuel use delta. IMO if one is considering a half dozen episodes or so a year of a few hours outage, that is not significant, one can live with it.

If one is thinking of a frequent / regular usage duty-cycle, and I think this is more what you have in mind, to me also it does not seem a good approach.

My RV power system has a 300Ah battery that weighs about 100lbs and it is charged by a dedicated alternator anytime the engine is running. I agree with @sophiecentaur that this doesn't make sense as a dedicated solution for home power - too heavy, not very accessible, and if I were to drain that battery it would take an hour or so to charge it to 50% and another 4-6 hours to get it to 100%, that is a LOT of driving, way more than I do on a daily basis.

 

[Johnny Yuma]

Around the house we have a charcoal grill (for outdoor use only) and a LP camp stove to use in our garage. A small battery powered TV and a portable radio. 6 battery powered LED lanterns. Lots of "Hot Hands" which are hand/foot warmers made of iron particles that you crush to provide heat for 3+ hours. Freezer has a lot of ice bags.

We have a motorhome inside a shed with LP tank for stove, fridge and furnace. Onan generator that runs on gasoline and 4 6v golf cart batteries that are charged via the Onan or by our gas engine. In past years we have spent a day or two in here waiting out power outages. Two 40 gallon waste tanks help out.

Why not talk to friends who have an RV...or maybe visit RV dealerships and ask many questions about off the grid living.

 

[harborsparrow]

We use a cheap inverter bought from Amazon, with its end adapted to clip onto a car battery. Then, we can use the car battery to run a couple of LED lamps at night and charge up phones and computers. It's a low cost solution and requires only a few minutes to set it up. An extension cord fed through the window to the middle of the house completes the setup. The last time there was a major outage for us (2 weeks), the internet and TV service itself was down anyway and cellular (if you could get it) was the only option. At these times, it's good to have a Kindle reader or something similar with lots of books loaded on, because it will run on battery for a very long time and can be read after dark at low power (as opposed to using, say, a Kindle app on a mobile phone or tablet).

For heat, we have an emergency kerosene heater which can provide not only heat but light and can boil water.

 

[bob012345]

We use a cheap inverter bought from Amazon, with its end adapted to clip onto a car battery. Then, we can use the car battery to run a couple of LED lamps at night and charge up phones and computers. It's a low cost solution and requires only a few minutes to set it up. An extension cord fed through the window to the middle of the house completes the setup. The last time there was a major outage for us (2 weeks), the internet and TV service itself was down anyway and cellular (if you could get it) was the only option. At these times, it's good to have a Kindle reader or something similar with lots of books loaded on, because it will run on battery for a very long time and can be read after dark at low power (as opposed to using, say, a Kindle app on a mobile phone or tablet).

For heat, we have an emergency kerosene heater which can provide not only heat but light and can boil water.

Did you mean the power was out for 2 weeks or it happened two weeks ago?

 

[.Scott]

I live in southern NH where power is normally pretty reliable. But winter storms can bring down trees and utility poles and being at the end of a dead end street, we are not high priority when utility crews are planning recovery. So over the past 27 years, we have lost our power for 3 to 5 days on about 5 occasions.

I use a 5 Kw generator. I have it going to a separate breaker box that allows a manual switch between generator and street power. So everything coming out of that box is backed up. Everything that is still coming out of the original box is street only. In NH, you are allowed to do this rewiring on your own - in most places you would be required to hire an electrician.

Here's what I put on the new box (with generator backup):
1) The heating system. It is oil, but it needs electricity to run.
2) The water pump.
3) The refridgerators.
4) The main living room air conditioner.
5) The microwave oven.
6) Some lights and electric outlets.

Here's what I did NOT put on the new box:
1) The stove and oven.
2) The clothes dryer.
3) The dishwasher.

Some surprises:
1) The A/C does not consume as much power as I expected.
2) The TV is important. As mentioned by others earlier, it creates a sense of normalcy. At some point you want to resume your normal routine and ignore the power outage. Especially if you have kids or teens in the house, it's important.
3) Consider a heavy duty 100 foot extension cord - for those neighbors that have not been as well prepared.

If you keep the freezer door closed, the contents will stay frozen for over a day.

We do not loose our internet connection. Our provider has units with battery backup mounted on utility poles. Those batteries die after about a day - but then the company goes around a puts little generators at the foot of the pole and runs them continuously to keep the internet running.

Maintenance:
1) Do not run the generator indoors (not even in your garage).
2) The generators should not be run within 10 feet of an open or partially opened door or window.
3) Even if you follow those rules, you can get into trouble. In one case, a neighbor was running a generator about 25 feet from an open garage door, but there was a light breeze bringing the CO into the garage and the home. His concentrations reached 80ppm when the fire department responded.
4) It is best to test you system every 3 months. If there is something wrong, it is much better to deal with it when power is available than when it is not. Possible issues will be damage from animals and gasoline gelling in the carburetor.
5) You will probable want to store 10 gallons or more. You should add some kind of "dry gas" to it when you buy the gasoline. I prefer to store gasoline in a shed separate from the house.

 

[PCnerd]

Summary:: Considerations for design of an emergency battery backup system for TV/Internet during power outages.

I am looking for the right size of battery/pure sine-wave inverter to power a system for a few hour when there is a power outage. The system of TV/DVD/Internet uses less than 200 watts at about 1.6Amps. I could just buy a commercial system which runs about 1000$ or assemble a similar design for about one-half to one-third the cost. Any thoughts?

I think what you might be looking for is one of the new battery "generators". Something like the EcoFlow Delta Pro 1300, or the Jackery 1500. Google them. The EcoFlow Delta Pro (their largest unit) can supposedly run a refrigerator for most of a day. They can be recharged with your plugging into a 110 outlet, car, optional solar panels, a gasoline generator from outside, or even can be taken to one of the public Electric Vehicle recharging stations. You can also daisy chain them for more power. With 4 or 5 daisy chained, they can even be used as a 'Whole House' battery back-up. But they are expensive. It could be cheaper to buy a really good inverter, a battery terminal spot welder, lithium batteries, and build your own.

Oh, and those units do provide pure sine-wave power.

 

[bob012345]

I think what you might be looking for is one of the new battery "generators". Something like the EcoFlow Delta Pro 1300, or the Jackery 1500. Google them. The EcoFlow Delta Pro (their largest unit) can supposedly run a refrigerator for most of a day. They can be recharged with your plugging into a 110 outlet, car, optional solar panels, a gasoline generator from outside, or even can be taken to one of the public Electric Vehicle recharging stations. You can also daisy chain them for more power. With 4 or 5 daisy chained, they can even be used as a 'Whole House' battery back-up. But they are expensive. It could be cheaper to buy a really good inverter, a battery terminal spot welder, lithium batteries, and build your own.

Oh, and those units do provide pure sine-wave power.

I estimate it costs about one third to one half to build the system yourself but they basically contain a 12V 100Amp-hr battery with the inverter and some other electronics in a nice package you can carry around.