$170 battery backup.

[tinkabranc]

Wow thats alot of snow for October.

Curious to see how long you get out of that setup- keep us posted

 

[MountainStoveGuy]

Sorry to disappoint you MountainStoveGuy but you will get nowhere near 60 or 70 hours of run time. Amp hours are not calculated that way. By this calculator you will get 2.5 hours if you are lucky.

http://www.xantrex.com/support/howlong.asp

i have no idea... its been on batter power now for 16 hours. and the stove is running constantly in this cold weather.[/quote

I am sold ,I can't wait to see how long it will go . Have you got a meter to check the battery voltage to see when it starts getting low . I don't think you want to
be running with low voltage .

Still running this morning, if the voltage does get low, the control bord flips out and the stove will not run. I had a customer that installed a accentra insert on a switchable outlet. He didnt realize that the switch was in the off position during installation and the first 3 days where on the battery system without him knowing. He called me with some very strange error codes on about day 3. Harman could not figure out what the codes ment, so i went out and tested the outlet. No juice lol.

 

[amick780]

MSG,
What are you using to charge the battery when it runs low? Does the inverter charge it or do you need a seperate battery charger? What brand/model inverter are you using?

 

[MountainStoveGuy]

I have a small float charger that puts out 750 mA @12 volts connected to the battery at all times. Im not a expert with these things, its what the guy sold me at batteries plus. I will have to check the inverter brand, i do know its some off brand Chinese cheapo for $69 bucks. Its only a modified sine wave, which concerns me a little with the control board. Im not a expert on these things, but so far so good.

 

[amick780]

Thanks for the info, sounds like a good setup if you are able to get 16hrs out of it. I am using a computer UPS and it will only run for about 30mins. I would be willing to switch to your setup with that kind of run time. Got any pictures of it? Just wanted to see how big the setup is behind the stove. I don't have a ton of clearence behind my stove. Its in the corner of my room.

 

[MountainStoveGuy]

the battery is like this, but the 90 aH version not the 75.
http://www.batteriesplus.com/pc-36456-36456-SLI24MA.aspx
the inverter is this one:
http://www.batteriesplus.com/p-27054-600w-1800w-dcac-inverter.aspx
batter charger is this:
http://www.batteriesplus.com/pc-36126-36126-DBT021-0123.aspx

 

[Dr_Drum]

I don't know anything about the battery or the inverter, but the Battery Tender brand charger has been keeping my ATV and Dirtbike batteries going for years. They are the recommended brand on Thumpertalk.com (motorbike web forum). I really like your idea, thanks for the info.
Mike -
Edit: Dirt bike battery is original Yuasa gel battey from 2003, and ATV is original Yuasa from 2001.

 

[imacman]

I have a small float charger that puts out 750 mA @12 volts connected to the battery at all times.......

MSG, do you have the battery charger connected and charging now while you're running the stove off the inverter?

 

[Corey]

90 amp hours / 1.5 amps = 60 hours, but you'd also have to figure in inverter efficiency which is usually around 50-60%, so you're probably looking more at 30 hours run time.

 

[MountainStoveGuy]

I have a small float charger that puts out 750 mA @12 volts connected to the battery at all times.......

MSG, do you have the battery charger connected and charging now while you're running the stove off the inverter?

I do.

 

[MountainStoveGuy]

90 amp hours / 1.5 amps = 60 hours, but you'd also have to figure in inverter efficiency which is usually around 50-60%, so you're probably looking more at 30 hours run time.

the inverter data says its 90% efficient. I got about 59 hours. The batter was not full when i started. I think i would change out the inverter to a true sine wave inverter. Occasionally it would "pulse" the electricity. In otherwords it would shut off then on within a few seconds, not really interrupting the burn, but annoying never then less.

 

[amick780]

I have a small float charger that puts out 750 mA @12 volts connected to the battery at all times.......

MSG, do you have the battery charger connected and charging now while you're running the stove off the inverter?

I do.

So, you are charging the battery while you were running the stove on battery? Wouldn't that skew your run-time?

 

[imacman]

I have a small float charger that puts out 750 mA @12 volts connected to the battery at all times.......

MSG, do you have the battery charger connected and charging now while you're running the stove off the inverter?

I do.

So, you are charging the battery while you were running the stove on battery? Wouldn't that skew your run-time?

That's what I wondering when i asked about the charger.

MSG, you'll never get a true measurement of how long the battery will last if the charger is still hooked up. To get a true read on that, disconnect the battery from the stove, charge it to full charge, then run the stove with only the battery, no charger attached.

If the power does goes out, the charger won't be on to help the battery.

 

[Corey]

90 amp hours / 1.5 amps = 60 hours, but you'd also have to figure in inverter efficiency which is usually around 50-60%, so you're probably looking more at 30 hours run time.

the inverter data says its 90% efficient. I got about 59 hours. The batter was not full when i started. I think i would change out the inverter to a true sine wave inverter. Occasionally it would "pulse" the electricity. In otherwords it would shut off then on within a few seconds, not really interrupting the burn, but annoying never then less.

Good deal - sounds like yours is a lot newer / more efficient than my old clunker. Though I have also noticed the 'cleaner' the sine wave, the more power gets wasted in the act of generating it - though maybe a newer sine wave inverter would still be pretty efficient..

 

[mark d fellows]

Well, we got 36" + of snow yesterday, and im surprised we did not loose power. I am not a good boyscout so i was not prepared if it did. I purchased a modified sine wave 600w inverter, a 90 ah deep cycle marine battery, and a auto top off/float charger that can be plugged in constantly to the battery. The Harman XXV draws 180w continuous power, which is ~1.5 amps. This set up should give me 60-70 hours of backup heat. (i hope)

I'm really not sure what is going on here. Your calculation is correct on the output side. 180/120 is 1.5 amps.

However, on the input side to the inverter you will draw much more current.

I get about 15 amps of current draw on the input side of the inverter. Greater than that even factoring efficiency loss of 10% making it 16.5 amps.

90/16.5=5.45amps Roughly six hours of run time as you describe your setup.

Of course, you say you were charging the battery at the same time, so that would account for a longer run time. 59 hours though, I don't think so, unless your charger is providing much more than 750mamps.

Mark

 

[MountainStoveGuy]

I ended up with about 5 days worth with the charger plugged in and working. The 180 watts is max input, so perhaps on the low setting it draws way less?

 

[imacman]

I ended up with about 5 days worth with the charger plugged in and working.

MSG, I still don't understand why your testing the running time with the battery charger hooked-up.....wouldn't you want to know how long it will last without it (real conditions)?

 

[MountainStoveGuy]

because im a idiot sometimes. :-S

 

[amick780]

I'll be interested to see how long your setup runs without the charger hooked up and a fully charged battery. Keep us updated when you test it again.

 

[MountainStoveGuy]

the charger is only 750 mA, but still skewed my test im sure. Im going to test again when i get a good sine wave inverter. Perhaps the same model as the markas mentioned in another thread.

 

[mark d fellows]

the charger is only 750 mA, but still skewed my test im sure. Im going to test again when i get a good sine wave inverter. Perhaps the same model as the markas mentioned in another thread.

I recommend getting at least a 79AH sealed lead acid battery. They can be had for 160.00 or less.

I am sure you know this, but just in case, please make sure you get a sealed lead acid and not one for use outdoors only, like your auto battery.

 

[imacman]

I recommend getting at least a 79AH sealed lead acid battery. They can be had for 160.00 or less.

I am sure you know this, but just in case, please make sure you get a sealed lead acid and not one for use outdoors only, like your auto battery.

Like this? (broken link removed to http://www.apexbattery.com/deka-unigy-24hr3000s-ups-battery-12v-79ah--ups-batteries-deka-unigy-ups-batteries.html)

I tried Froogle.com for a price, and the cheapest was $160 + shipping. This one is $200, but free shipping.

 

[mark d fellows]

I recommend getting at least a 79AH sealed lead acid battery. They can be had for 160.00 or less.

I am sure you know this, but just in case, please make sure you get a sealed lead acid and not one for use outdoors only, like your auto battery.

Like this? (broken link removed to http://www.apexbattery.com/deka-unigy-24hr3000s-ups-battery-12v-79ah--ups-batteries-deka-unigy-ups-batteries.html)

I tried Froogle.com for a price, and the cheapest was $160 + shipping. This one is $200, but free shipping.

I see that the rating comes from 24 hours, most I know are 20 hour ratings. I really don't know what that means. Is that they drain the battery for 20 or 24 hours at a certain rate and then extrapolate the data? I am boggled by this.

I did see a 79Ah battery on Amazon one for 160.00 but I don't know what the shipping charge was. At the time, I was planning to get two. I think it was an MK something battery.

Mark