DIY 12VDC water warmer

[Snarg]

BMaverick,

I am anxious to see the results of some real-world testing. How long, at full charge, will that battery power the 1157 bulb at 38W? Please, keep us posted. Thanks.

 

[Bear Foot Farm]

Quote: Convert the Watts to Amps, and divide that into the "Amp Hour " capacity of the battery.

Allow for some current loss, and the fact it's not good to fully discharge the battery, and you'll get a rough idea

http://www.powerstream.com/Amps-Watts.htm

 

[BMaverick]

BMaverick,

I am anxious to see the results of some real-world testing. How long, at full charge, will that battery power the 1157 bulb at 38W? Please, keep us posted. Thanks.

We have been awaiting too. The temps are in the mid 60s, so nothing to report yet. The system has not even turned itself on since the thermo-cube kicks it on when temps get at 35F or less.

 

[84097newbei]

I use the pale and nipple system and hang it inside the coop(2 1/2 gal due to coop size) With it getting colder here I started looking for ways to keep the water from freezing. I bought a "fish tank" heater for 12.00 and it works great! It warms a 5 - 15 gal tank AND it will shut off if there is no water in the tank (pale)

 

[BMaverick]

I use the pale and nipple system and hang it inside the coop(2 1/2 gal due to coop size) With it getting colder here I started looking for ways to keep the water from freezing. I bought a "fish tank" heater for 12.00 and it works great! It warms a 5 - 15 gal tank AND it will shut off if there is no water in the tank (pale)

Does this run on 12VDC from a battery?

 

[sires6]

Convert the Watts to Amps, and divide that into the "Amp Hour " capacity of the battery.

Allow for some current loss, and the fact it's not good to fully discharge the battery, and you'll get a rough idea

http://www.powerstream.com/Amps-Watts.htm

Umm.. Actually, some kinds of batteries are designed to be fully discharged. I use marine batteries on my e-fence for the horses and we discharge them completely and then power them on a charger.

 

[OldGuy43]

Quote:
Umm.. Actually, some kinds of batteries are designed to be fully discharged. I use marine batteries on my e-fence for the horses and we discharge them completely and then power them on a charger.

True, but a discharged battery will freeze. When fully discharged they contain only water. That's why a hydrometer is the preferred way of testing a battery.

Sorry, didn't mean to sound negative. I love the concept. I have a suggestion. Rather than trying to warm the water set the warmer to come on at about 36-38 degrees F.(4-6 C.). That way you get an assist from thermal inertia, instead of trying to overcome it.

If you've ever lived near a large body of water you know what I'm talking about.Temperatures are always moderated closer to the shoreline.

 

[BMaverick]

Umm.. Actually, some kinds of batteries are designed to be fully discharged. I use marine batteries on my e-fence for the horses and we discharge them completely and then power them on a charger.

Yes, that is the very reason why my setup uses the Marine/RV DeepCycle gel-cell battery vs. a standard battery. These batteries can run down to 20% power and be recharged much like a cell phone or other rechargeable batteries. I've recharged my NiMH battires well over a 500 times for my 13.2VDC cordless drill. I've even ran the warmer off of it easily.

Cold weather isn't bad for battieries. They can work down to -40F easily. The hot temps above 77F are an issue for battries. Going 15F+ over 77F can kill the life of a battery.

Anyways, I have the solar to keep the battery going with the MorningStar charge controller.
"Battery charging voltage also changes with temperature. It will vary from about 2.74 volts per cell (16.4 volts) at -40 C to 2.3 volts per cell (13.8 volts) at 50 C. This is why you should have temperature compensation on your charger or charge control if your batteries are outside and/or subject to wide temperature variations. Some charge controls have temperature compensation built in (such as Morningstar) - this works fine if the controller is subject to the same temperatures as the batteries. However, if your batteries are outside, and the controller is inside, it does not work that well. Adding another complication is that large battery banks make up a large thermal mass."

Read up on Deep-Cycle batteries here .... http://www.windsun.com/Batteries/Battery_FAQ.htm

Hope this helps ...

 

[BMaverick]

Convert the Watts to Amps, and divide that into the "Amp Hour " capacity of the battery.

Allow for some current loss, and the fact it's not good to fully discharge the battery, and you'll get a rough idea

http://www.powerstream.com/Amps-Watts.htm

27W / 12VDC = 2.25A. 160Ah battery / 2.25A = 71.111111 capacity

Wow, I get 71.111111 for the battery capacity. That's great!

Plus, the solar charging during the day is a plus. We live within 10 miles of "the sunniest spot in Tennessee", Orlinda. Thus, the solar is the best deal.

 

[OldGuy43]

Quote: SOURCE:

http://www.trojanbattery.com/Tech-Support/FAQ/Maintenance.aspx