What type of battery is good for emergency power for blackouts?

[Ghost314]

A tornado came through my city recently and leveled a major transformer station, which shut the lights off across the area for around 55 hours. I already have a UPS that has seen me through a lot of shorter outages, but I was not really prepared for a multi-day blackout.

I'm thinking about buying some kind of battery that I can potentially use as an emergency power supply the next time this sort of thing happens. I live in an apartment with no balcony, so anything that produces toxic fumes (like a gas powered generator) is pretty much a no-go. It's also pretty difficult to make use of a solar panel as I hear they don't get much energy behind a window (not to mention the weather is not usually good during a blackout).

Based on the research I've done over the last few days, I get the impression that I should be looking at AGM batteries for the following reasons:

• Can store quite a lot of power
• Low cycle life is irrelevant
• Weight is irrelevant
• Can be safely kept at full charge, ready to go
• Requires no ventillation
• Lower maintenance than some other options

Before I make any decisions though, I wanted to ask some people who know more about batteries than I do, if I'm on the right track, or if there's a much better option that I'm missing.

I am also interested in whether or not it's at all realistic to try and keep any sort of battery for 15 to 20 years and still expect to use it. I ask because the last time I saw a multi-day blackout like this was literally 20 years ago, so I'm guessing the next one won't happen for another 20 years or so.

I have a bad feeling that cheap alkaline batteries that need to be replaced every few years may be the only realistic option for that kind of time-frame, but I would love to have something a little more hefty on-hand.

 

[(*steve*)]

The best battery for this type of situation is likely to be a tank of diesel.

You need to make sure nothing affects the diesel whilst in storage.

 

[davenn]

Based on the research I've done over the last few days, I get the impression that I should be looking at AGM batteries for the following reasons:

• Can store quite a lot of power
• Low cycle life is irrelevant
• Weight is irrelevant
• Can be safely kept at full charge, ready to go
• Requires no ventillation
• Lower maintenance than some other options

The one very important thing you haven't told us is, WHAT do you want to power during a blackout ?
Anything other than some lighting is going to require a very serious power supply system

Dave

 

[kellys_eye]

....propane? Less prone to degradation, easier to store/transport (containers are 'built-in'), variable size containers, can be used 'directly' for hot water and cooking etc.

There are propane powered generators around and also propane conversion kits.

As per @davenn the actual answer depends on your consumption needs.

 

[(*steve*)]

Yes, there are cases when the mechanical hydrocarbon-oxygen primary fuel cell is the easiest and most reliable option.

 

[hevans1944]

I'm thinking about buying some kind of battery that I can potentially use as an emergency power supply...

I hope you have learned from other posts on this thread that battery power alone is not a good solution for blackout conditions, mainly because you don't know how long the blackout will last. Even the largest battery bank is eventually depleted by an extended blackout condition. After depletion of their stored energy, the batteries must either be re-charged or re-placed, so they are a temporary "solution" at best and a non-solution at worst, if after years of storage they fail to deliver their "stored" energy when it is needed most. What you need during blackout conditions is a reliable source of backup power, typically provided by a gasoline, diesel, or natural gas fueled motor-generator set.

Another (more expensive) alternative is hydrogen/air based fuel cells. These are currently used by EMT first-responder teams to power up medical diagnostic and treatment equipment in the field. Later, the hydrogen fuel is replaced by high-pressure electrolytic separation of hydrogen from water at the operations base using locally generated power. The hydrogen is stored in high-pressure (about 400 psig) gas bottles for transportation to trauma sites. This is not a very efficient system, but it works well as a field-portable electrical power source that can be hand-carried when and where power is needed. It is probably not affordable by your average consumer of electricity, but there are no toxic fumes generated, so it is suitable for use in an apartment by anyone with deep pockets full of cash.

We live in Florida and it is currently (September-October 2018) hurricane season. Last year Hurricane Irma downed power lines in our neighborhood (and elsewhere) when trees fell on them. We were without utility-served power for almost a week. There are also frequent lightning storms (Florida, especially southwestern area, is the "Lightning Capital of the World") that often cause brief power outages that are typically ignored by a UPS system. However, any power outage lasting more than a few minutes will defeat most consumer UPS modules by depleting the energy stored in their small battery.

However, a properly designed UPS can protect against power-line transients and surges caused by nearby lightning strikes. Nothing will protect from a direct lightning strike to a power line, but the UPS protects against induced transients and surges from nearby strikes by first rectifying the AC power line to DC and storing the DC in a battery. Then it uses an inverter, galvanically isolated from incoming AC power, to produce AC power for external loads. It is important that there be no "switchover" to inverter power to prevent transient surges. The inverter must run continuously, whether input AC power is present or not, powering the loads attached to the UPS. When input AC power fails, the inverter simply continues to run, without so much as a hiccup, from battery power until input AC power is restored.

So, we have a gasoline-fueled motor-generator set that provides about 3500 watts of 120 VAC, 60 Hz, power when Florida Power and Light (FPL) fails to provide us with electricity. This is enough power to run a few lights, a television set, a couple of laptop computers, our Internet fiber-optic service, and maybe our refrigerator and a small chest freezer.

To my dismay and chagrin, our MG set does not produce 220 VAC which is necessary to run two submersible pumps used for our well-water system: a 1 hp pump for the well and a 1/2 hp pump for the aerator. So, just prior to the arrival of Hurricane Irma, we filled a bathtub in the guest bathroom with water and, with a small bucket, used it to flush the toilet. Later, after the storm passed, I purchased a used 1:2 ratio step-up dry transformer from eBay that I will now use to operate the water pumps. But there is no way that anything less than about 10 to 12 kW will power our 220 VAC whole-house air-conditioning system, electric water heater, and electric cooking range. As soon as I can afford it, I will be looking into buying a "whole house" dual-fuel backup motor-generator set that runs from gasoline or propane. I doubt that I will go so far as to bury a propane tank in a side yard, but the "barbecue grill" sized tanks (about 20 lbs net weight) are convenient to use and readily available everywhere.

MG sets, however fueled, must either be operated outside or, if inside, in a sealed and ventilated enclosure with separate combustion air intake and exhaust outlets . In either case, inside or outside, exhaust fumes must not be allowed to enter living areas. This is not possible if, as you stated, you live in an apartment building with no outside balcony. You must consider moving if extended power outages are unacceptable to you, and if such outages are anticipated to re-occur in your area. With the overloaded and degrading infrastructure of the North American power grid, extended outages and "brownouts" are soon to be the expected norm. I don't suppose a petition to the apartment building manager, to install a motor-generator set to service the entire building, would be an effective alternative, but it could be worth investigating... if you live in a "prepper" community environment.

 

[Audioguru]

Many people live in high rise apartment buildings that have a single elevator and no generator. They complain to TV news that they are stranded when it takes a week or more to replace the worn out elevator or there is an electricity blackout and they are in a wheelchair. People complain about flooding when their home is at the bottom of a hill or on the banks of a river.

I complain that I have reliable underground electricity, I don't live in a high rise apartment nor at the bottom of a hill nor on the bank of a river and am not in a wheelchair because I never have any of these excitements.

 

[hevans1944]

...am not in a wheelchair because I never have any of these excitements.

Maybe you just haven't lived long enough yet, despite your common-sense precautions to avoid excitements.

 

[kellys_eye]

We live (relatively) remotely and frequently suffer power outages due to trees on the lines and having at least ONE portable generator makes life so much more 'relaxing' during those periods. Very quick and easy to set up - wire a change-over switch and external socket to further simplify the process etc.

It's rare to have an outage longer than 24 hours but the small generators we use (inverter-type) are ideal to power TV, internet, laptops and lighting in the main house (heating is via wood stove and hot water and cooking is via propane anyway) and a separate one is used to boost the freezers (which can survive 48 hours without defrosting anyway) if required.

Avoiding heavy electricity-consuming devices is key - water heaters, home heating etc - but that isn't always possible for most.

It's fun (but that's a matter of opinion!) figuring out how to SHTF-proof your home!

 

[Ghost314]

The one very important thing you haven't told us is, WHAT do you want to power during a blackout ?
Anything other than some lighting is going to require a very serious power supply system

Dave

I thought about including that, but left it out on purpose, as I'm not entirely sure myself yet. The answer largely depends on what's possible for an apartment with low ventilation, and how much it costs. I don't really consider having energy during an outage a necessity in the first place, just a convenience.

I get the impression that some of the suggestions are a fair bit more than I wanted to spend, so I think I'll try throwing out a potential budget. I definitely wouldn't want to spend more than $1,000.00 (CAD) on this. That is a maximum upper limit, ideally I would like to spend closer to the $500.00 (CAD) range. I am willing to buy some things I might not normally, if they have the potential to be useful outside of the extended blackout scenario (ex: power converters or general tools).

I had largely written off fuel-based motors and generators as either too expensive or too hazardous for my circumstances. As a consequence, I had also largely given up on being able to power a fridge or a stove, as I imagine you would need to spend more money to run those.

Here are some things I would like to power, in order of priority:

1. Flashlights
2. Radio (for news/announcements)
3. iPod
4. Cell phone
5. Lap top (probably pushing it)

Anything more power hungry than those, I figured would not be possible without spending a lot more. Depending on how long the outage lasts, I can also picture myself starting to sacrifice some things and rationing power.

Of course, if it's possible to do more with the amount that I'm willing to spend, that would be great, but I figured it wasn't. Also feel free to chime in if you can think of something important I should add to that list.

 

[Tha fios agaibh]

I don't know where you could find one (military surplus store?) but a guaranteed backup for low powered devices like that is an old fashioned dynamo. Basically, you turn a crank and it drives a generator to produce power.

Myself, I'm a bit lazy with my auto start up standby generator that runs on natural gas.

 

[kellys_eye]

Your power requirements are approximately:

1. 2-3W
2. 2-5W
3. 1-3W
4. 1-5W
5. 50-120W

Worst case is around 140W but that assumes all items in use, all the time. Realistically you would be looking at the lower end of the range so around 60W. This is a 'piddling' amount in terms of battery storage.

A reasonable 120A/hr leisure battery has a capacity of 1440Whr so about 10 hours at your worst case scenario or 20 hours+ in a realistic situation. This would equate to two to three days use (or more, depends on how fanatical you are...)

Use your cellphone as a flashlight, music player and radio (potentially even internet access too) and you're down to ONE item that takes 5W to charge so aforementioned battery could keep it topped up for DAAAYS - weeks even.

Keep a few spare cellphone batteries as 'backup' and/or a spare cellphone entirely.

It's all 'relative' and depends on how you approach what you think is a 'problem'.

Personally, in your situation, I'd get a few (say 6-10) of those USB 10000mA battery banks (decent quality) and keep them charged and use them cyclically to keep them 'fresh'. Our local 'mart has them for £10 each - cheaper and easier to manage than a large lead-acid leisure battery and 'trade able' if the issue arose.

One wall wart charger could maintain them all and the total size could fit your jacket pocket.

 

[BobK]

A 20000 mAh power bank would power your cell phone for 10 days. You should be able to find a rechargeble flashlight that has a 5V charge port, so the power bank will handle that too.

I would look for other devices than can run off such a power bank.

These devices are dirt cheap compared to other types of batteries because they are a mass narket item. And the charging is done via a phone charger which ypu probably already have multiples of.

Bob

 

[(*steve*)]

Beware that most power banks rate their capacity as the mAh rating of their battery. A 20000 mAh device has a 3.7V 20000 mAh battery in it (if you're lucky).

Assuming an 85% efficient boost converter that translates into 12600 mAh at the output.

A safe assumption is that you get half of what I'd claimed.

 

[Ghost314]

I don't know where you could find one (military surplus store?) but a guaranteed backup for low powered devices like that is an old fashioned dynamo. Basically, you turn a crank and it drives a generator to produce power.

Myself, I'm a bit lazy with my auto start up standby generator that runs on natural gas.

This is actually a very interesting possibility for me. Now is probably a good time to mention that I happen to be a cyclist. I got into the habit in university and never really stopped. I work as a software developer and my main hobby is gaming, so I figured cycling would help keep me in shape. At this point cycling is my main method of transportation, I don't even own a car.

I may not be the most impassioned cyclist out there, but the important thing is, pedaling is a normal part of my daily life, and I'm extremely used to it. I can go for hours on end if the occasion calls for it. I always knew there were special components you could add to your bike to generate power while you ride, but I grossly underestimated the technology. I pictured Bart Simpson struggling to pedal one foot at a time to charge a headlight.

Turns out those little energy generating components are actually small dynamo generators, and you can get much larger and more efficient ones. I did a quick check and found some specifically designed to be used as power generators during an outage. They lift the bike's rear wheel off the ground and turn it into a sort of stationary energy producing exercise bike.

It looks like these things can produce a lot more power than I ever expected from a man-powered device. From what I'm reading, producing upwards of 100W, should be very easily achievable. If I can generate enough power with my bicycle to put even a partial charge back into my UPS, then I can use the UPS to supply nice stable power to whatever I want to charge. If I store up some energy for a while, I might even be able to run some things I wrote off as impossible, for a few minutes.

Best of all, I was able to find some generators that are well below even my idealistic budget of $500 (CAD) that still claim to produce a respectable amount of power. I'm starting to think that I should take a much closer look at this option, as it would be great to have the ability to produce brand new power, and not have to worry about rationing a limited supply.

 

[Tha fios agaibh]

You can buy crank flashlights, radios and even one's that will charge your cellphone like this one


But what's in my mind is ww2 era military dynamos that you'd crank and it had a mainspring that would keep it operating about 3 minutes after you'd stop cranking.

Perhaps you could rig something similar to your bicycle to make a super dynamo?

 

[hevans1944]

I definitely wouldn't want to spend more than $1,000.00 (CAD) on this. That is a maximum upper limit, ideally I would like to spend closer to the $500.00 (CAD) range.

It isn't possible, IMHO, to provide a backup power source that meets your other requirements for that amount of money. OTOH, your short-list of five low-power items does seem to be doable with lead-acid battery technology, specifically the AGM variety in a sealed, no-maintenance, package. Depending on whether any of your equipments can operate directly from DC power, you might not even need a DC-to-AC power inverter... just a few DC-to-DC voltage converters to supply the correct DC voltage to each device... flashlights, radio, iPod, cell phone, and laptop. You would also need a "float charger" to maintain charge on the AGM lead-acid battery when normal utility power is available prior to a blackout.

You would need to size the battery, i.e., specify an ampere-hour energy according to how much energy you would expect to use during a short-term power outage, and perhaps purchase an inverter capable of running your laptop battery charger if you can't, or don't want to, run the laptop from an AGM battery.

They lift the bike's rear wheel off the ground and turn it into a sort of stationary energy producing exercise bike.

It looks like these things can produce a lot more power than I ever expected from a man-powered device. From what I'm reading, producing upwards of 100W, should be very easily achievable.

It is NOT easily achievable. An athlete in excellent condition can produce 100 watts of electricity by pedaling a bicycle... for a short period of time. It is exhausting exercise to produce 100 watts on a continuous basis, even with an efficient recumbent bicycle. You can check this out at a local gym that has bicycles with variable pedaling efforts and electronic readouts showing how much energy you produce while pedaling.

Of course you don't have to produce 100 watts while pedaling... ten or twenty watts might be maintainable for an hour or more, and this level of energy production would replace some of the energy depleted from your AGM battery. I think you will want to rig up a bicycle with a variable gear ratio... maybe not twelve speeds, but certainly more than one. Be sure to connect a voltmeter and an ammeter to the generator (or alternator) output and use a computer to digitize and measure these two variables. You will want the computer program to display the rate of energy production in watts, as well as the total amount of energy produced during a pedaling session.

 

[(*steve*)]

A fit person can produce 50 to 150 watts for an hour.

That is energy expended, not energy captured, so the power available for charging batteries etc would be lower. Then you need to think about charging efficiency of the cells, and the efficiency of the charger.

However, the fact that 1 big Mac should provide enough energy for about 8 hours may be a bonus feature.

 

[hevans1944]

1 big Mac should provide enough energy for about 8 hours may be a bonus feature.

A big Mac contains about 563 calories. One calorie of food energy is equal to 1.16 watt-hours. When I do the math, it tells me that if I were to get into excellent shape and pedal hard to generate 100 watts of power, then after an hour of pedaling, my big Mac meal would provide me with 563 x 1.16 watt-hours = 653 watt-hours of energy, presumably to be stored in a battery for later use. Dividing that number by 100 watts yields 6.53 hours of pedaling energy produced from one big Mac at the rate of 100 watts per hour. I suppose that's "close enuf" for about 8 hours of energy production per sandwich, but there is no way I would pedal for 6.53 hours, much less 8 hours, for a single big Mac sandwich. There would have to be a super-sized Coke and large fries included with the meal... and maybe a couple of baked apple pies too.

 

[Ghost314]

My earlier statements were mostly based on a quick glance at the available generators within my price range, and some of the manufacturers are throwing out some really bold claims about how much energy they produce. I'm currently in the process of looking up more information from people that actually have these things to try and get a better idea of the real-world output. Turns out, a lot of people have forgone the store bought products in favor of building their own