12V Battery and Fresh Water pump

NewEnglandCamper · 05-02-2021, 12:45 PM

First time and New NoBo 16.2 owner.

Planning our first road trip with enough distance and scheduled in such a way that we need to consider stopping and sleeping overnight (CT to Bar Harbor). We currently weekend at sites with full hookups, and have not yet needed to utilize the fresh water tank and pump.

Last week filled the tank and I ran the pump off of the onboard 12V battery. It performed, but I noticed that the pump seemed to sound “weaker” as it ran longer than a minute or two, and in typical first time owner fashion, I panicked and cut the pump off fearing any low voltage damage.

My questions are:

Is the 12V onboard battery suitable to run the pump, sustainably, or do I need to turn it on and off between uses? Should I do that regardless of running the water pump while connected to shore power/generator?

If connected to my vehicle, and not shore power (battery only) does that change anything?

Generator and battery upgrades are on my TD list.

Thanks!

NavyLCDR · 05-02-2021, 12:50 PM

The water pump will build up pressure and shut itself off until a faucet is opened and pressure drops to turn the pump back on. Since this is your first fill and pump use, the pump was initially pumping air until it got water to the suction from the fresh water tank. You now have a large amount of air in the plumbing system and the pump slows down as it builds pressure, but will take a long time to hit the pressure shut-off setting of the pressure switch because it has to compress the air injected into the plumbing system.

You need to turn on the pump and open both a hot and cold faucet. When air stops spitting out, then turn off the faucets and the pump should shut itself off after a few seconds.

Then you can turn on the water heater. Don't turn on the water heater until you get the air out of the hot water side of the plumbing.

WanderMore · 05-02-2021, 12:55 PM

The water pump should have an automatic pressure switch. To insure its best operation you should run water through all the lines so you are not trying to pump against air.

Your tow vehicle will generally only supply a small amount of current. Some are designed by the manufacturer to only supply while the vehicle is towing. Some are not. The last thing you want to do is drain your tow vehicle battery.

NewEnglandCamper · 05-02-2021, 01:49 PM

Quote:

Originally Posted by NavyLCDR

The water pump will build up pressure and shut itself off until a faucet is opened and pressure drops to turn the pump back on. Since this is your first fill and pump use, the pump was initially pumping air until it got water to the suction from the fresh water tank. You now have a large amount of air in the plumbing system and the pump slows down as it builds pressure, but will take a long time to hit the pressure shut-off setting of the pressure switch because it has to compress the air injected into the plumbing system.

You need to turn on the pump and open both a hot and cold faucet. When air stops spitting out, then turn off the faucets and the pump should shut itself off after a few seconds.

Then you can turn on the water heater. Don't turn on the water heater until you get the air out of the hot water side of the plumbing.

Seems like I ran the pump until it was primed, but did not allow it to reach the needed PSI to shut itself off.

Thanks for the feedback.

Any issues with running on the standard 12V battery or is that not what it’s intended to power?

WanderMore · 05-02-2021, 01:55 PM

No problem other than the original 12 volt battery probably doesn’t have a very high amp hour rating. Do you have solar to help keep the battery replenished?

NewEnglandCamper · 05-02-2021, 02:00 PM

Quote:

Originally Posted by WanderMore

No problem other than the original 12 volt battery probably doesn’t have a very high amp hour rating. Do you have solar to help keep the battery replenished?

I do not, have read while searching here that the TV doesn’t charge much while connected.

This makes me hesitant to use the battery for just about anything besides internal lights until I am able to sink a bit more coin into upgrades.

WanderMore · 05-02-2021, 02:06 PM

Be careful with the tow vehicle connected while camping. Some disconnect the tow vehicle charge when not running and some don’t. You don’t want to drain your tow vehicle battery down unless you’ve got one of them there old timey hand crank starters.

NavyLCDR · 05-02-2021, 02:11 PM

The water pump will only draw power from the battery while it is running. Once you get all the air purged out of the system the water pump will only run when a faucet is opened or a toilet flushed.

BobHanke · 05-03-2021, 12:46 PM

WARNING!! Be sure the water heater has water before turning it on. You can also get water from hot side of faucets when in bypass mode. Best to check at the high pressure relief valve on the heater. That can also bleed off air in the heater. Only a few seconds of running the AC side of the heater, if you have a dual model, can destroy the element if no water is present.

mnoland30 · 05-04-2021, 10:03 AM

You should be able to run your refrigerator (on propane), lights and water pump for several days just on battery power. The heater blower will run the battery down. The question is, how good is your battery? YOu might want to have it checked at an auto parts store before your trip. A 100 watt solar panel with charge contoller isn't too expensive, and will allow you to boondock indefinitely if you're careful with battery use. Or, buy a 2 stroke generator from Harbor Freight for emergency charging of your battery. In a pinch, use jumper cables from your car to charge it. I have 200 watts of solar, and 2 golf cart batteries wired in series, and can boondock until I run out of water.

NewEnglandCamper · 05-05-2021, 09:31 PM

Quote:

Originally Posted by mnoland30

You should be able to run your refrigerator (on propane), lights and water pump for several days just on battery power. The heater blower will run the battery down. The question is, how good is your battery? YOu might want to have it checked at an auto parts store before your trip. A 100 watt solar panel with charge contoller isn't too expensive, and will allow you to boondock indefinitely if you're careful with battery use. Or, buy a 2 stroke generator from Harbor Freight for emergency charging of your battery. In a pinch, use jumper cables from your car to charge it. I have 200 watts of solar, and 2 golf cart batteries wired in series, and can boondock until I run out of water.

Thanks for the feedback this helped a bunch.

Thanks to all other replies as well, I found some very useful info in them.

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