I don't know anything about this stuff.  Would it be possible to run a 115V well pump from a 12V deep cycle battery with a power inverter for short periods?  How about a refrigerator?  I was thinking this might be a cheaper solution for short term power failures than a generator.  Long-term, is there a solar powered charger that could charge a 12V battery?  A generator is only useful if gas is available, and if power is out long term, there is no more gas.

Short answer : YES.
But a 24 volt battery bank   is better.

The simplified answer is yes. A charge controller connected to the battery and the solar panel will do the trick.

I haven't tried it, so this is just a guess.

How long do you want to run the well pump off of the battery? If it is just a few start/run/stop cycles over the course of a day, maybe you could do it. If you are looking for more frequent usage and/or longer duration usage, then a single battery (without any means of recharge) is unlikely to be satisfactory.

My own well pump requires something like 5,000 watts to start it, and maybe less to keep it running after it first starts.

To do that off of a 12-volt battery and an inverter is not an easy thing. First, an inverter capable of supplying 5,000 watts (and maybe more) at 110 volts is a pretty big puppy - you can get them for maybe $400 or more depending on quality, so it is at least feasible to do from the perspective of finding an inverter.

If the inverter were 100% efficient (which it is not), then your 12-volt battery would need to supply on the order of 400 amperes of current for long enough to get the pump started, then some lesser value while it runs until it is ready to cut off. A typical automotive starter battery is designed to provide such an amount of current for a short period, but it is not designed to provide sustained power at high currents. A deep-cycle marine battery is designed for sustained discharge, but not for super-high current draw. You would have to do some calculations based on the ampere-hour rating of whatever battery you chose (and the discharge curve for that battery) to be sure.

So I'm not optimistic that you will get good results from a single battery. Maybe a battery bank would be better, but even with that my best guess is that you are looking at a short-term proposition unless you have some method of recharging it.

Short answer:  Yes



Honest answer:  Battery + Inverter that really works will cost just as much as a generator that gets the job done.



 



 

A quick Google search shows me that there are DC well pumps out there.  If running off batteries, running a DC pump with a battery bank will be more efficient than using and inverter to take your DC power and turn an AC pump.  (And if you'd need a pretty big inverter to do it, may be more cost effective)

That same Google search showed that some companies have already rigged up nice little kits with DC pumps and solar panels.

Yup. You will probably end up getting a generator to charge the batteries anyway. Solar simply won't keep up to any kind of demand (without a big system, anyway). This being said, I can run our 120VAC 1/2HP well pump all day long, starting and stopping, on a 3k Watt Home Depot Generator. Cost $200 on sale for the generator.

 

My solution was to pump water to a large holding tank(500gal) using the generator. After that I used a 12v booster pump with a deep cycle battery to pump water to the pressure tank.  The batteries are charged by a battery charger. I havent purchased a solar panel for it yet. I only use this during power outages the longest was 13 hours. This lets me use the genny  to power other things. This kept me from having to purchase a big inverter an multiple batteries while letting me use a smaller more fuel efficient generator to power my home instead of running a big generator all the time. Hope this helps.

Would using a small drive to limit inrush start up
be of any use in any of these systems?

Thanks!

John

Sure, but not for long. demand to high for consistent use. epically if well is deep. starting power is the problem. Might as well buy a generator and be done with it.

Ditto.

Forget about the solar battery charger, they don't generate  enough power to recharge your battery A generator is your best solution.

A high amp draw motor like a submersible pump would kill a battery in short order. Especially supplying a small pressure tank. The start stop cycles would quickly kill a battery.
The best solution, depending on your circumstances, would be to have a large storage tank, on ground or above ground, and a solar pump filling it all day on solar alone. Then if you have an elevated tank you are set. It doesn't take a lot of pressure to meet your needs. Most municipal water systems run under high pressure because of the volume of users. When 30k people flush at the same time they want it to work.
If your tank is on the ground, you will need a pressure pump like an RV has. These will do fine on a battery.
In the event you have multiple cloudy days, you can make up a cable to supply your system from your car. Just remember to idle it while pumping the well.

Seems like a solution, I hadn't thought of an RV pump.   Freezing would be an issue though.  I thought of a water tower, maybe 10ft high (house is a rancher), but the freezing issue made me scrap it.

Give this thread a look...

http://www.ar15.com/forums/t_10_17/636974_Household_backup_water_supply.html


And some low cost charging options for charging.
Still a generator, but a little different.

http://theepicenter.com/tow02077.html

Insulation and heat tape would solve the freezing problem. Also dripping a faucet at the far end of the pipe run keeps the water flowing and helps warm the pipe.

your well is how deep?
the pump is at the top of the well, or is it submersed at the bottom of the well?
what is your total water need, per day, in gallons?
for how long would you need to do this?  1 day?  7 days?  1 month?  indefinitely?

these are important parameters in terms of sizing your backup power system.

ar-jedi

where does the power from the heat tape come from?

ar-jedi

It's a deep well, at least 250 feet, I had to dip it once, and ran out of line.  Jet pump, not a submersible.  Water requirements in emergencies would be minimal.  Under 30 gallons, probably half that.  I would love a completely autonomous setup for indefinite use, but that's probably not realistically done.  I live 50 yards from a clean freshwater lake, and I could carry water in our bladders if need be.  So I won't die without a setup.

Possibly enclosing the base of the tower stand and insulating it. Thermal mass from the ground should keep the temperature inside above freezing. Run the piping in this enclosure. If necessary a small fire could keep the temperature up.

Thermal temp from the ground here in the north east wont keep your water tower thawed when the temps dip below 0...
Our camp is off the grid and has a water tower that we supply via gas powered water pump and water line from the lake which is about 100+yards away.  
When the temp dips into the teens at night we have all we can do to keep the system thawed when the camp is kept at 70* and the water tower is heated with propane.
We do this during hunting season and it works fine for us, but come a self sustainable situation where your propane tanks are not going to get a refill your best of shutting the system down for the winter and getting a few buckets full of water from the lake as needed.  

OP: I have done a little work before on deep well pumps and if your pump is down at 250 feet then you are really going to have a hard time starting that with an inverter IMO.  Not saying it cant be done but there is also a good chance you burn your pump as well.  There is a lot of head pressure at 250 feet plus the pressure tank pressure.  

If you have a lake 50 yards away I personally wouldn't worry about it beyond having a gen set for power outages...  

My issue at my current house is the closest water source is 1/4 mile way.  (Other then my deep well + genset)