Stupid Battery Question

[Rain City]

Ok I have 2 x 250 watt heat lights that I'd like to run off a battery. How do I figure out how long x size battery would run them? Ideally I'd like to use a cambodian tire charge pack or something if I can. This is for keeping chicken warm and is the only thing that requires power in my setup. The chicken sits on racks in chafing dishes so this is only half the warming.

 

[Rain City]

For example, say you want to run a 250 watt 110VAC light bulb from an inverter for 5 hours. Amp-hours (at 12 volts) = watt-hours / 12 volts = 1470 / 12 = 122.5 amp-hours. If you are using a different voltage battery the amp-hours will change by dividing it by the battery voltage you are using.

https://www.powerstream.com/battery-capacity-calculations.htm

Thanks?

 

[Trophy]

No stupid questions just stupid people that dont ask questions, lots of smart answers on this forum as the one from stormtrooper has kindly supplied.

 

[Corey_lax]

All I heard was CHICKEN!

 

[Rain City]

No stupid questions just stupid people that dont ask questions, lots of smart answers on this forum as the one from stormtrooper has kindly supplied.

He's a smart cookie for sure. I tried reading the link and smelled smoke.

 

[macro]

Group 24, 70-85 Amp hours, 12 volts. Group 27, 85-105 Amp hours, 12 volts. Group 31, 95-125 Amp hours..

So hypothetically a group 27 battery - 12v*100amp=1200 watts . 1200/500= 2.4 hours... in actuality. Lead acid batteries are garbage and wont do a high discharge over a long period.. Read on the Peukert effect if you want to know more.. In actuality . In this example.. More like 70% of its rated capacity . So 1.68 hours give or take.

Better answer - figure out how to do it with propane. Lead does not have the power density required. Or spend major major money on lithium batteries.

Good luck

 

[bigdogeh]

Consider getting one of these... might work out cheaper than purchasing batteries.

https://www.amazon.ca/Monitor-Therm...=1549054337&sr=8-3&keywords=diesel+heater+12v

https://www.amazon.ca/s/ref=nb_sb_ss_i_2_13?url=search-alias=aps&field-keywords=diesel+heater+12v&sprefix=diesel+heater,aps,200&crid=31Q6EVNQD52ZJ

Lots of youtube vids that give a little info on them also.

 

[sasqman]

To piggy back off this. My house battery is a group 27 AGM. Roughly 100 amps, or 1200 watt hours.
This is the info off my fridge.
In my calcutions, my fridge, in theory, should run about 8 hours? Is that right?

 

[macro]

To piggy back off this. My house battery is a group 27 AGM. Roughly 100 amps, or 1200 watt hours.
This is the info off my fridge.
In my calcutions, my fridge, in theory, should run about 8 hours? Is that right?
View attachment 57604

If it was running the whole time.. likely less.. lead does not like full discharge. Likely will only be running when cooling so will likely run longer.

 

[Wild Bill]

500 continuous watts off battery!
Our motorhome I have 4 gc2's, started with 2 however with my ear I can tell differences in rpm so at night I could hear the furnace slowing down, 10 below kinda stuff. Put 400 watts solar on top and configured it to run fridge off inverter saving propane on sunny days and fully charged batteries at night. Works great for boondocking!
Acerage above French beach ran a larger bar compressor fridge off 1000 watt psw inverter, 2 8D batteries and 500 watts solar and trailer loads plus fridge was good for 3 days overcast. No issues sunny.
Wanting heat lights above the chicken? Otherwise propane would be easy and inexpensive filling at Costco..
1000 watt or smaller quiet generator?