1st real test of battery backup setup

[leatherguy]

Just finished a 14 hour test of my Eko 40 battery backup system. I loaded up my boiler at 8:30 last night ( it was running at 184deg ) closed it down and at about 9pm the power went out. So after about 15 min and realizing the power wasn't coming back real soon ( it had flickered 3 times during the day due to a major ice storm followed by heavy winds and dropping temps) I went down to the garage/ woodshed/boiler room to check the boiler. The controller said 170 deg the blower fan was off ( I have a relay that kills power to fan when main power goes out) and pump was running ( 750 watt dirty sine wave inverter- charger and walmarts biggest of the shelf 12v deep cycle battery). Perfect except boiler is full of wood. I went to bed. At 4:30 am still no power boiler is 167deg pump still running. At 8:30 am I notice that the battery indcator lights on inverter say LOW BAT. So I open the boiler and pull out 8 pieces of wood 2 - 5 gal pails 4 black and 4 charcoal like (coked). Boiler still at 165 - 170 deg. Power is restored at 11am. Reflections!!
1, I am real pleased with my backup system but want to fire the operator;
2, why would anyone fill the boiler during an ice/wind storm knowing that there is nearly a 100% chance of a power failure.
and 3, why did i leave all that wood in the boiler at 9pm. I don't like handling burning firewood in my skivies.

 

[Pat53]

LOL, well maybe you just got lucky, but at least now you have a good idea of what your system is capable of, congrats.

 

[NYEDGE]

Sounds like it was a success for the most part.
It's great that you were able to "reflect" on how you actions could have helped you better.
I know that sometimes in retrospect I find myself wondering why I did something so obviously foolish.
Good of you to share the experience, and plant a seed in others head's on how to adjust their habits if found a similar circumstance.

 

[leatherguy]

Thanks, Thats what makes this site so great everybody sharing there experience (good or bad) If it wasn't for this site I wouldn't even have a gasifier, never mind getting clues about setting it up and then protecting it.

 

[jebatty]

It's pretty easy to get a good approximation of how long a battery/inverter can provide backup power, especially if you have a Kill-A-Watt or similar, but you don't need that. With the Kill-A-Watt, plug everything that needs to be backed up and push the VA (not watts) button. Divide that by 6 = Cautious Load. Take the rated amp-hour capacity of the deep cycle battery and divide it by the Cautious Load. That will be about the number of hours that the fully charged battery will run the backup system to a point of 50% discharge, which absent a real emergency is as far as you ought to run down a deep cycle battery. If you don't have the Kill-A-Watt, add up all the wattages, multiply by 1.1, and use that for the VA number.

Example: need to backup controller, boiler fan(s), 1 circulator = 200VA / 6 = 33. Battery amp hour rating = 100 / 33 = 3 hours to point of 50% battery discharge. If you wire two batteries in parallel, you can double the run time. And you can run down the batteries further, but real deep discharges shorten their life.

 

[dpsfireman]

Question, why not just run the blower too from the battery? Since you have storage you could probably power the boiler and circulator long enough to get through a burn cycle on the battery and store the heat. That is the way I have mine setup. I used a 300w sine wave inverter and with the circulator and blower running I just measured the current from the battery at 12 amps. I think the battery capacity is around 70 AH so that should run the system 5 hours on a charge in an emergency. When I measured the blower was running at a lowered speed because the temp was nearing max so the current would be a bit higher at the beginning of a burn.

BTW, it is typically more efficient to use an inverter that is not a lot greater capacity than needed. I like to see a device such as these to run at 50% to 70% capacity to maximize efficiency. I would not run one at 100% though. I have seen way too many electronic components run that way that don't last long.

 

[leatherguy]

The blower fan wouldn't run on the non "pure" sine wave, and I had already bought the inverter. I plan on getting a small generator someday but I think that also needs to be a pure sine wave for the blower/fan to work.

 

[dpsfireman]

I initially tried a non-sine wave inverter and it wouldn't work for the blower. The problem is caused by the blower speed control.

Here is the unit I bought: http://www.altestore.com/store/Inve...amlex-300W-24V-Pure-Sine-Wave-Inverter/p2521/

 

[Duetech]

Hey leatherguy,
I have the EKO40 as well. Since you have battery back up to keep the circ working you can take a simple precaution to prevent boiler overheat incase of power outage. On the other hand you can completely close your secondary air supply tubes, I have done it and the fire will eventually die unless power comes back on. Of course if you have a bigger back up system and radiant heat you can keep the home warm by running the boiler and the circs you need to feed your zones. A system that big though is just a few steps from an off the grid system.

 

[timberr]

Personally I have a unit that is a 1500 Watt Inverter with/built in charger and transfer switch and it is pure sine. It runs the whole heating system, I have tested it for 5 hrs which is longer then a full burn cycle. I also have a generator for longer outages. I was more worried about a back-up system that would run without me during the weekday's. The intake fan runs fine.

 

[dpsfireman]

timberr,

I tried to find a unit like you described but couldn't so I settled on the inverter and built my own relay/transfer switch. I have also added a charger/batter maintainer so it is always fully charged. Just curious, where did you get it and what battery do you use?

 

[timberr]

When I purchased mine 2 yrs ago this is were I got it, they were the cheapest.

http://www.boatandrvaccessories.com/PWRIC150012S.htm

I just use on deep cycle battery, my system can have 3 circ's running at once. I also have 4 Tekmar controllers which is originally why I wanted to go with pure sine.

Good luck

 

[dpsfireman]

Nice unit. A bit overkill for my system but nice. I power only my boiler and the charge loop circulator. If the power goes out the zone valves open and I get some heat from convection. Most of the time the I use the generator so the battery gets very little use.

 

[timberr]

I agree it is but I wanted to feel comfortable leaving the house at 6:30 AM with a boiler full of wood and come home at 5:00 to a warm house and no surprises in the basement. I live in a rural area and usually once a month we lose poor for 1-2 hours (this month it has happened 3 times) so it is worth it in my mind.

Good luck

 

[dpsfireman]

Good point. I work at home and fire the boiler in the evening so it would be a rarity for me to not be there when the boiler is running.

BTW, I don't know how they get away with calling to output of most of these units a modified sine wave. The waveform of these is more like a square wave or pulsed wave than a sine wave. It's not even close IMHO.

 

[HeatFarmer]

This is exactly what I need here on the farm....... We regularly loose power due to wind or accidents on the road... Because I am on the Fire Department I have to be going to calls usually when we have a power outage, so I can't be at home tending backup systems or shutting down boilers..... Can someone describe their transfer relay and how you leave your backup UPS system hooked up?

Thanks

 

[Fred61]

This is the one I have. I have it hooked up to three deep cycle batteries out of my Motorhome. I tried the modified wave inverter and didn't like the humming circulator motors and the blinking controller LEDs so I returned it in favor of this one. It's expensive but I sleep better knowing I am not doing damage to my electrical components.

http://www.aimscorp.net/1500-watt-pure-sine-power-inverter-with-built-in-transfer-switch-charger/

 

[firecracker_77]

I know they aren't cheap, but compared to flooding from failing sumps pumps for example, an investment in a whole house generator is a bargain. If you can swing it is peace of mind to know you always have power for your core systems like heat and water removal.

I had enough money from a flooding insurance settlement to get a Generac, and I sleep alot easier when the skies look nasty.

 

[Jesse-M]

timberr,

I tried to find a unit like you described but couldn't so I settled on the inverter and built my own relay/transfer switch. I have also added a charger/batter maintainer so it is always fully charged. Just curious, where did you get it and what battery do you use?

I'm interested in making my own automatic transfer switch if anyone can help me out with info.......