NH ice storm and advice for inverters

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Hbbyloggr

New Member
Nov 3, 2006
84
NH
www.firewoodinnh.com
Greetings,
After the ice storm in NH and one week without power the lessons I learned along the way seem to point out the need for a cheaper source of electricity to run the two Taco 011 circulators on the OWB. Our 30 kw propane fired generator easily kept up with our electrical needs but it came with a $ 100 per day fuel cost. Shutting down the generator for more than 3-1/2 hrs ( to save fuel $ ) allowed the OWB to boil over. We rotated sleep shifts in the family to keep 3 hrs " off", 2hrs on ,during off peak hours at night.

I've been reading posts of Nov 08 regarding Inverters to power the circulators-only during power outages. I think that is what I need to get into. Our back up wood stove in the house keeps us nice and warm but I need to keep the circulators powered up to keep the OWB from boiling over. There is no need for us to keep a 30 kw genset running all night to keep two small circ's powered up, right?

I am looking for advice on inverters to keep these two Taco 011 circulators running for 8-9 hrs. During the " Generator-on" cycle the battery trickle charger would bring the batteries back up to " ready" for the night time hours. Your comments would be appreciated.

Happy new Year !

Bill, aka Hbbyloggr
 
Well, a 0011 draws 1.76 amps peak, so you need to be able to supply a bit under 4 amps. At 120 volts, that's 480 watts, so call it 500 watts, minimum.

That's peak draw, but actual draw will vary due to pumping conditions (pumps operate more or less efficiently at different flow conditions. To size the battery bank, you will want realistic data on actual draw, which may be significantly less than peak. Hooking up a amp meter would let you take a "snapshot" of power usage, but you can buy/rent/borrow a "kill-a-watt" meter (that's the name of the most popular brand) and use it for a day, to see how much power the boiler draws during a day.

If the purpose of this is just to keep the boiler from actually boiling, then just running the pumps will be fine. If you are going to build a backup system anyway, you may want to actually power the entire heating system, which would require that all loads be calculated, not just the two pumps. Even if you don't buy enough batteries to accomplish that, sizing the inverter and charger to allow for future expansion might be a good plan.

Also, are the two 0011 pumps sized correctly? Unfortunately, many installers don't necessarily size pumps correctly, preferring to be safe by using a "bigger is better" approach. Running overly-large pumps on batteries can really drain the batteries much faster than they need to be drained. If you can detail what each pump does, and what piping they need to pump through, I (or someone else, if I don't see your reply first) should be able to tell you if those pumps are sized correctly for what they are doing. If they are not, dropping to a smaller pump would reduce draw.

Joe
 
Joe,

Good advice for the " needs" amps draw. The OWB is a 450 k btu, heating two zones in the house plus the domestic HW ( circulated with one primary Taco 011 ) and the other primary Taco 011 circulates heat for the 40x60 garage/ office and dry kiln. The OWB is 125 ft from each location through 1" pex. The circulators are on full time 24/7/365 .

The genset is a little overkill even for our needs but it is built for many years of service, will not beat itself to death after a few days of constant running like the small cracker box toys , provides clean power --- and I liked the color.

I don't really need to provide inverter power to keep the entire system up and running during off-peak times, just the two main circulators. There are plenty of heat dumps in the system to draw heat without using the Zone circulators in the house. Can you quesstimate how many watts something like this will need without a data run ?
 
Without knowing all the details, it's a guessing game.

Sizing for "worst case," you're looking at a 500-watt inverter, and something close to 400 amp-hours of battery capacity (in deep-cycle batteries, not standard car batteries).

Call it $2k-3k, if using high-quality components, based upon some napkin math...

If the system isn't actually operating in a "worst case" situation, the cost may be dramatically less.

Joe
 
Do a search on battery back up, there's another thread on this topic. I'm waiting on a transwitch 700W inverter/charger/transfer switch unit (cost $227 inc. shipping). Hopefully this will run my system during a power outage. Don't forget the amp draw of the OWB, does it have a blower? Will the OWB operate on a modified sine wave? True sine wave inverters are considerably more expensive. Does anyone know what the amp/hour capacity is on a typical marine battery? I have the largest ones Walmart sells and they're three years old. If they've always been well maintained how long do they last? Most batteries list cold cranking amps. instead of amp hours. Would 100 amp/hours per battery be typical?
 
Thanks Joe,

This estimate is for each circulator ? The two are on the same circuit in order to power them with the generator. Will one inverter do to run them both together or should I get two inverters and run them separately ? Thanks for the help.

Bill
 
If you plan on a scenario where you need power for the OWB for more than a couple of hours, I would suggest purchasing a small, quality (sine wave) generator. A 1000 watt inverter generator (Honda eu1000i for example) would provide plenty of power and at a cost of about $700-800 is very reasonable compared to a battery bank plus inverter. It wouldn't be auto start on power failure, but your whole house unit should cover that until you could switch over.

If you go the battery/inverter route, you need to determine VA not watts. A safe estimate is volts x amps / 0.7 = VA.
 
atlarge54 said:
Most batteries list cold cranking amps. instead of amp hours. Would 100 amp/hours per battery be typical?

Starting batteries and deep-cycle batteries are different critters.

Discharing a starting battery much is bad for it, but it can deliver a lot of amps quickly.

Deep-cycle batteries don't deliver much by way of "Cranking amps," but you can discharge 80% of the energy in the battery on a repeated basis, without harming it.

Weigle Tree Service said:
This estimate is for each circulator ? The two are on the same circuit in order to power them with the generator. Will one inverter do to run them both together or should I get two inverters and run them separately ? Thanks for the help.

The numbers I used are for both. The prices are very rough guesses, not even estimates. I just did a quick web search for components that seemed appropriate.

Joe
 
Weigle Tree Service said:
Greetings
Our 30 kw propane fired generator easily kept up with our electrical needs but it came with a $ 100 per day fuel cost.

I've been reading posts of Nov 08 regarding Inverters to power the circulators-only during power outages. I think that is what I need to get into. Our back up wood stove in the house keeps us nice and warm but I need to keep the circulators powered up to keep the OWB from boiling over. There is no need for us to keep a 30 kw genset running all night to keep two small circ's powered up, right?

I am looking for advice on inverters to keep these two Taco 011 circulators running for 8-9 hrs. During the " Generator-on" cycle the battery trickle charger would bring the batteries back up to " ready" for the night time hours. Your comments would be appreciated.

I assume you already know that a propane generator is about the most expensive to run when it comes to dollar of fuel per watt. To make things worse, a large generator is very inefficient when run on a low -load. That's why big generators are much more efficient when run for short times at high loads to charge battery banks and then, shut down. Note that one exception is a generator that does NOT need to run full speed for proper Hertz, i.e. a DC generator run through an inverter that can load-sense and run slow or fast and still make good AC power.

If you don't require an inverter that comes on automatically, you can buy a pretty rugged 3000 watt inverter for $140-$150. I've got several I've been using hard for years to run power tools, TV, computers, etc. at a remote site.

For you to run your circulators for 9 hours, you're going to need a minimum of 700 watt hours of battery storage, and that's cuttting it close due to several losses along the way. Two 6 volt golf-cart type batteries - e.g. Trojan T-105s or Dekas, hooked in series will give you around 2800 watt-hours of storage - i.e. they will run your circulators for 4-5 hours. Obviously, four batteries will run 8-10 hours.

If you don't want to buy dedicated 6 volt deep-cycle batteries, you can buy somewhat inferior 12 volt sort-of deep cycle batteries instead. This way maybe you've got an alternative use for them in the summer - like starting a tractor, running an RV, etc.

A true, mid-priced deep cycle battery will often last over 10 years, but you pay for it. That would be something like a pricey Trojan L-16. An "almost" true deep-cycle battery is the golf-cart type I mentioned which are often cheaper in the long run if bought right -and can last 7-8 years.
Going down hill to cheaper, you can buy Walmart combo 12 volt deep-cycle marine batteries. They are cheap and sometimes last 4 years.

The most exspensive deep cycle batteries are 2 volts each, cost a fortune, and can last 20-30 years. Cheap car batteries don't do well with long steady draws. So - somewhere inbetween is usually the best bang for the buck.

By the way, true deep cycle batteries work fine as cranking batteries. When compared to an equal sized cranking battery, they usually are good for 75-80% of the cranking capacity, but work fine as long as sized right. I mention, because you can take deep cycle batteries and use them for cranking machinery in the summer if you can fit them in.

One more note - about your plan to use the DC trickle charger from your genset? I doubt it. If you draw 60 amps an hour from your battery bank, for 9 hours - it will take 10 hours at a 60 amp charge ratet to replenish those batteries. No way is a trickle charger going to work. So, you need to have a battery-charging plan.

Some large inverters made for solar and back-up have built in 60-100 amp chargers - e.g. Trace, Outback, etc. I'll also mention, that even if you have a large shop-type high-rate battery charger - it might not work when plugged into your generator. Most electric generators do not make AC power good enough to run conventional battery chargers. That because normal grid 120 VAC is actually 170 VAC that jumps back and forth. Most battery chargers get their power from the 160-170 volt peaks. Many gensets only make AC power that peaks at 140-150, instead of 170 VAC. So, often battery chargers do NOT work well. There are many work-arounds.

Some people use automotive 12 volt alternators run by small gas engines for "bulk" battery charging. They work great just as long as you have a 12 volt battery bank.

Other remedies are - using a step-up "correction transformer, or - just buy an higher-priced electronic battery charger that WILL work off of inferior AC power. Iota is one popular brand and makes them in 12, 24, and 48 volt models.
 
I looked at some battery info. and it appears trolling motor batteries run approx. $2/amp hr. Medium size is approx. 50 amp hr., with larger ones being 100 amp hr. I'm not sure if these are true deep cycle batteries or not. My greatest fear would be extended power outage and possible frozen lines from lack of circulation.
 
Wow! Iv'e learned more in one day than I ever dreamed. Thanks guys for the info. Interesting facts about charging batteries. Is it reasonable to assume that I could have a bank of batteries charged from the alternator of the Chrysler powerplant . It would give the generator another hat to wear and use a little more of it's potential. When the generator is shut down during the off peak time at night, separate ( big knife switch ? ) the Battery Bank from the Gen's battery and power up the inverter.

The real reason I went with the big generator was the price. It had 200 hrs of exercise time and auctioned off by one of our neighboring towns. Price: $ 700.00. It's an Onan with a slant-six engine, one of the real bullet proof engines of all time.
The propane keeps well and I have enough storage to go a week or better non-stop, plus I installed a gas cook stove to add to the survival list. While it is expensive to run I didn't have to find my way through downed trees and power lines to try to find a gas station that was opened. I talked with lots of customers during our firewood deliveries who said they were using between $25 and $75 a day in gasoline, depending on the size of their gen's., and they had to prowl around trying to find a station that was opened. It's even more of a problem when you're without power for a week or better.

It's a fun time fine tuning the aftermath of a major outage, right ?
 
atlarge54 said:
I looked at some battery info. and it appears trolling motor batteries run approx. $2/amp hr. Medium size is approx. 50 amp hr., with larger ones being 100 amp hr. I'm not sure if these are true deep cycle batteries or not. My greatest fear would be extended power outage and possible frozen lines from lack of circulation.

The price of an amp-hour depends much on the usual life-span of the battery. You can buy some marine batteries for 50 cents per AH.

For cheap batteries, I've bought several marine combo 12 volt batteries from Walmart. Sort of a hybrid "almost" deep cycle battey made by Exide. Has two top round posts and also two threaded studs with wing-nuts. Last one I bought was $59 and it's 110 amp-hours. So, that's a little over 50 cents per AH. I've had a few fail at two years, but also have a few that have lasted 5 years.
I use them all year round. I stick them into our RV camper whenever we take it on a trip. I stick them in farm tractors for starting, etc. I've also used them at a remote camp - hooked to a large inverter to run power tools. They handy with the rope carrying strap and multiple hook-ups.

For years, Trojan T-105 offered the best bargain of them all - for a fairly durable deep-cycle battery. But, they've gotten very pricey. Same with equivalents from Deka. Two years ago, I bought a bunch of new Deka t-105 type golf-cart batteries from NAPA for $48 each. Now? They are $105 each. Still a relatively good buy, but not great at that price. GC2 type battery, 6 volt, NAPA # 8144, and 215 amp-hours. Remember, it's 6 volt -so when you hook two together to make 12 volts, it's still 215 amp-hours. So, for $210 you get 215 amp-hours from NAPA or Deka. And, from Walmart - if you buy a pair of 12 volt marine batteries for $140 total - put together their AH rating doubles and you also get around 220 amp-hours But, they usually will not last as long as the golf-cart style batteries.

Just remember that when you connect batteries in series - amp-hours stays the same.

Hook two batteries in parallel and amp-hours doubles.
 
Thanks for the info. jdemaris, you seem to have quite a bit of hands on experience with batteries. Do you happen to have any idea how much charge an automotive alternator will produce at idle speed? Would a typical auto charge the batteries and operate the boiler (2 pumps total draw 225 Watts@110v)?
 
Don't recall this having been mentioned in the posts above. Keep in mind that deep cycle batteries, regardless of type, should not be regularly drawn down to less than 50% of capacity. Draw downs to less than that shorten their lives, the greater the draw down the greater the impact, and full discharges can have a severe impact on their life spans.

If you are looking for the longest return on your battery investment, and determine, for example, a 200 VA draw, that equals 16.67 amps from a 12 volt battery. A 100 AH battery theoretically would provide that power for 6 hours. For best battery life, if you want to plan on 6 hours of battery power, you also should plan on providing 200 AH in battery capacity, then a recharge, before continuing the draw down.

Do you happen to have any idea how much charge an automotive alternator will produce at idle speed? Would a typical auto charge the batteries and operate the boiler (2 pumps total draw 225 Watts@110v)?

At some level of operating speed, a car alternator will provide 50-100 amps, with most newer cars at the upper range of that capacity. As to output at idle speed, it probably depends on your car and alternator, but I doubt enough to provide much of a charge. Assume a 25 amp charge, plus another 19+ amps to meet your boiler demand, that's about 1/2 the rated output of a large capacity alternator. Unlikely to provide this at idle speed.

You could do a rough test to see how fast you have to run your car engine. I think this should work, but others critique as needed.

With engine off and no demand on the battery, check open circuit battery voltage. It should be about 13 volts or a little more for a fully charged battery. Then start your car. Check voltage again. You likely will see about 14 volts or a little more, as the alternator likely will be providing at least a small charge. If voltage doesn't go up, then no charge is being provided, and if voltage goes down, then engine electrical demands are greater than alternator output at idle speed.

Now apply your external battery charge and boiler demand draw on the car battery, engine idling, and maintain this draw for at least a few minutes. Check voltage again. If it is anything less than 13 volts, the battery is being drawn down even with the engine idling. Increase engine speed to see what speed results in battery voltage of at least 13 volts. At that voltage amps in from the alternator are about equal to amps out from the battery.
 
The Prius is in a different category due to its very large battery capacity. The newer Prius has a battery pack roughly equivalent to 28 - 110 ah, 12 volt, batteries. If you have a Prius, you're probably in luck. But, each cell is rated at about 200 volts. So you will need a way to access the battery pack to provide the power. If you connect to the 12 volt batter under the hood, I don't know whether the main battery pack is wired to maintain that battery.
 
Get yourself one of those new Silverado hybrids. They have an inverter built in and a power generation mode that runs the engine intermittently to keep it charged up. You might be able to get one for less than $30k right now.

My Kohler pulls over 50% of its gas to just make 60HZ at no load. It is far more efficient to load it up when you run it. I charge up batteries on the UPS and for the inverters during the day and go to "silent run" at night. We have a sump pump that can't be neglected and it's nice to have a few lights and the TV during a power failure.

I've picked up used batteries at hamfests from people who have changed them out of big UPS systems. Sometimes, they are relatively short lived, but I have a pair of 75ah that have been in use for several years now that hold my UPS up overnight if I need them. Check the date codes!

Chris
 
How often do you loose power? And do you really want to go without access to hearth.com while you are out of power? Ice storm of 98 I bought a 5Kw generator and my insurance paid for 1/2 of it as it was to prevent damage to my home. Make a custom cable to allow connecting it up to your dryer outlet (if you have an electric dryer) and shut off the main to your house and fire it up. Yes its more expensive to run but when im out of power I dont want to go without eating or showering or any of my electronics. It powers everythin in the house except for the dryer (gas stove) We loose power several times a year and for 1/2 a day or more usually. THis last storm was for 4 or 5 days. No reasonable bank of batteries will cover these large storms and batteries are generally good for only 4-5 years. We have alot of UPSs at my work and Im constantly replacing batteries (gel type) Wet cell do last longer.

Ive had my generator now for 10 years and all I do it change the oil add gas and pull the starter, still has the original spark plug even.....

Just my 2 cents.

~ Phil
 
Any advice that includes hooking a generator up to an outlet without a properly wired transfer switch will end up killing someone and the transfer of all the property of the user of the generator to help defray the pain, grief and loss of the departed survivors'.

Do it right or don't do it all.
 
atlarge54 said:
Thanks for the info. jdemaris, you seem to have quite a bit of hands on experience with batteries. Do you happen to have any idea how much charge an automotive alternator will produce at idle speed? Would a typical auto charge the batteries and operate the boiler (2 pumps total draw 225 Watts@110v)?

A modern auto-alternator will easily put out 20-30 amps at idle speed. The old generators threw out half the power they made since brushes selected the DC from the AC. An alternator uses all the AC but converts to DC. So, an alternator makes twice since it uses just about all the power it makes. The reason why newer cars have bigger alternators then the past IS just for the reason of low speed charging. Power at idle-speed since thats when low-charge problems can show up. Take a car, truck, or RV - with the radio or CD player blasting, kids in back maybe watching a DVD, air condtioner on, etc., and - if at night - headlights - and then come to a long red light with the engine idling. Then you've got problems unless you can get a high charge-rate at engine idle. So, when a car comes with a 100 amp alternator - it's NOT to give you 100 amps - it's more so you can have 20- 30 amps at idle.

Also, when I say "modern", I'm calling suff from the late 1970s modern. I've got may bulldozers, backhoes, and farm tractors that have Delco 10SI alternators on them. The 10SI used to be the cheapest and most common General Motors alternator with a built-in regulator. They are usually only 60 amps - but all easily put out 20 amps at engine idle. The newer alternators since the late 80s and on, usually put out more,and often, a lot more.

Remember though - that "idle speed" is a result of pulley sizing. On cars, alternators usually have smaller drive pulleys to make them run faster in relation to the engine RPMs. In farm tractors, often larger drive pulleys are used to slow the alternator down. The main reason being - by slowing it down, it turns less in it's life, and in theory, lasts longer.

For people living off the grid with solar panels and battery banks - small chargers built from auto alternators and small gas engines work great for DC charging - as long as that battery bank is 12 volts. A five horse engine - hooked with a belt to an 80 amp alternator is cheap to build and works great. And yes, you can just hook to your car or truck and do the same. Main problem is - taking a 100 or 200 horsepower engine - to run a 2 -3 horsepower load is very inefficient in the long run. One horsepower can make 500 watts all day long. So, in your case, a small engine will be much more efficient. But, since this is something you barely ever need to use - you have to balance all the costs - versus how bad you need the stuff.

I'll mention one kind of funny case. An woman lives near our place in the Adirondack mountains, but she's there full-time. Power goes out up there a lot. During one of the many outages, she got damage done to some of her household stuff. She got angry, called the power company and said she no longer wanted their crappy power lines. Then, with no pre-plan, she went out, got some batteries and inverters, and started running off a quickly thrown together battery bank. Every time it got low, she hooked jumper cables from the battery bank - to her little Honda Accord. She did this all winter. Yeah, sounds silly - but she was really pissed and still is. Since then, she's bought 2000 watts worth of solar panels, some DC appliances, and a Honda inverter generator. That generator runs a large battery charger when needed.
 
jebatty said:
Any advice that includes hooking a generator up to an outlet without a properly wired transfer switch will end up killing someone and the transfer of all the property of the user of the generator to help defray the pain, grief and loss of the departed survivors'.

Do it right or don't do it all.

I don't want to get into a long-winded argument based on anecdotal events over this - but here's my opinion on the matter. I worked for a few years as a lineman for Public Service Electric & Gas, and an emergency worker for Asplundh Tree Co. during many power outages. I say that just to indicate I've got a little first-hand experience on the matter from the emergency worker's perspective.

Any idiot can kill somebody - with just about anything. A gun, a rock, a large pumpkin dropped off a highway overpass, etc. Neither you, me, or the often clueless government is going to make society idiot proof - period.

Electrical linemen have rules. Rule #1 - when working with downed lines - is to always treat them as hot. In most cases, installing a ground-clamp to a downed line is required - just as an extra safeguard. The linemen ARE the trained professionals - and most of the time, when one does get killed - it was from breaking one of those rules. As a lineman, I got sanctioned a few times for not wearing my gloves when working with 13,000 volt lines. It's easy to get overconfident when you do this stuff every day.

A person could backfeed a large household outlet - e.g. a 30 or 50 amp welder or elec. stove outlet and do so safely. But, I'm sure many do not. For someone that goofs - or is clueless to start with - and sends power up to a power line - there's very little chance it's going to cause a problem. If there is a big demand on the other end - it will fry the generator almost instantly - or at least trip its breaker.

On the subject of someone really screwing up - and then, having a lineman make a mistake, and getting killed - I suspect you've got two negligent parties involved. Show me a verified case where a homeowner backfed his home-lines with no malice intended, killed a lineman, and then, lost everything he owned. Maybe this is true - but I'd like to read all the details.
 
When it comes to being safe and doing things right, we'll just have to agree to disagree on this one.
 
mpilihp said:
We loose power several times a year and for 1/2 a day or more usually. THis last storm was for 4 or 5 days. No reasonable bank of batteries will cover these large storms and batteries are generally good for only 4-5 years.

I agree with most of what you stated. Buying batteries is just plain annoying. They go bad over time, regardless if you use them or not. That's even true with so-called dry-charged batteries that are stored dry.

Like just about anything, though - you've got to balance the pros and cons. What suits one person may not suit another. You can buy conventional flooded lead acid batteries that will last 30 years. But, when compared to a battery made to last 5 years, you pay six times the price. No net savings.

For many people that I know - who do NOT have solar-electric - but DO have battery banks - they use those batteries for other things during the summer months. If a person can do that, it takes the sting out of having batteries just laying around, dying slowly. In my case, I have several alternative summer uses - that includes an RV camper - and also an off-grid cabin in the woods that we only use in the summer.

On a side-issue, I've got six farm tractors, two backhoes, and three bull dozers. All diesel, and each one has two large batteries. Also, I have two diesel pickup trucks and each one also has two batteries. That's 26 batteries that just sit there, dying slowly. That "battery bank" bothers me more than anything else. I wish someone would invent a battery that you could literally "turn off" and make it NOT die slowly when not being used. No such thing yet. Even if you special order a dry-charged battery with no acid in it - it has already been filled once and drained -and it has a time-clock ticking.

For someone who has no other need for batteries - it is not very expensive to just have bank of maybe four 220 AH 6 volt batteries. Hooked in series-parallel they will provide 440 AH at 12 volts. Used with a 3000 watt cheap inverter, and a small generator for recharging them - it's a setup that can run some households on bare essentials - and not have a generator running all the time. With many rural homes, the only big power draw is the 220 volt deep-well pump. But, if you have electric hot water - or an electric stove - forget it. You need something huge.
 
jebatty said:
Any advice that includes hooking a generator up to an outlet without a properly wired transfer switch will end up killing someone and the transfer of all the property of the user of the generator to help defray the pain, grief and loss of the departed survivors'.

Do it right or don't do it all.

Jim I work for the power company, my father is a master electrician and Ive talked to linemen about how I do it and their fine it with it. Its no different than what for the most part people on this forum are doing, they are setting up their own heating system IE wood burning and possibly integrated with some form of fossil fuel system on their own. Which if its a boiler and integrated into the fossil system is soposed to be done by a licensed plumber/heat tech but we use common sense, read and learn to do it ourself.

Could someone get hurt doing it the way I suggested yes, but a do-it yourselfer could also get hurt or hurt someone by playing with batteries and inverters... Do you know how much current a T105 can generate? Ever see what just a shorted r/c Nicad battery pack can do??


Its all about preference, I deal with batteries in UPSs alot and know they die, another point of regular maint and money sucking.... Plus if you dont test them on a regular basis and forget about them, when you NEED them they will probably be dead....

~ Phil
 
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