battery life

[Sarvi]

I know this subject has been beaten to death, however I have a question. This weekend I am dry camping, but will hardly be at the trailer. I'm a food vendor for the Oregon Jamboree, so will be there from pretty early in the morning until late at night, basically just using the trailer to sleep. There will be 4 of us, not eating much there, just sleeping and showering (water pump). I have 2 Interstate Deep Cycle Marine/RV batteries that the dealer put in new when I bought the trailer in January. I'm pretty sure they are each 12v. I don't want to bring the generator, what are the chances the trailer will be ok with what I have? I'm dropping the trailer off at the campsite Thursday evening, but not camping in it until Friday evening. I will be bringing it home Monday morning. Thanks!

[bill-e]

I've gone 3 days just using one old 12v battery to keep the fridge running, shower and lights for a few minutes as I was going to bed. I would think two new batteries (my new trailer has 2 new Interstate SRM-24 batteries) should be fine as long as you conserve.

[B-O-B'03]

The amount of draw will depend on the type of lighting you have, are they LED or regular incandescent bulbs?

I would think, with LED lighting and no more than you say you are going to be using it, your should be fine with 2 batteries.

You could always hook the TV up and charge the batteries if things get critical?

Definitely would do that, prior to bringing any slides or the awning.

Good luck.

-Brian

[Sarvi]

Regular bulbs. I bought a couple LED puck lights to light up the trailer a bit so we don't have to turn on overhead lights as much. I have one slideout, and a manual awning. I warned the kids that they are not allowed to turn on radio or tv, and the AC wouldn't work.

Quiet hours at the campsite are from 10pm till 7am. We won't get back to the trailer until probably midnight, and back out by 8am. I can't see lugging my heavy generator to run it maybe an hour a day.

[Festus2]

Originally Posted by Sarvi

I warned the kids that they are not allowed to turn on radio or tv, and the AC wouldn't work.

If "the kids" will be using the RV when you are away doing your thing and they have been "educated" about conserving the battery and are responsible enough to be prudent about using 12VDC without supervision, you should be okay.

I guess you'll find out soon enough if "kids will be kids".

[Sarvi]

Originally Posted by Festus2

If "the kids" will be using the RV when you are away doing your thing and they have been "educated" about conserving the battery and are responsible enough to be prudent about using 12VDC without supervision, you should be okay.

I guess you'll find out soon enough if "kids will be kids".

Lol I totally get it, but no, "kids" will be working right alongside me all day every day at the jamboree. They are 16 and 18 years old, and the 16 year old is bringing along her friend.

My concern now is if we'll have enough water for showers for us all! Temps will be in the upper 90s, and we'll be hovering over deep fryers for 14 hours a day. Ugh. There is water available, but it's a spigot and likely way too far for my 100ft of hose to reach.

[Festus2]

Bring along bottled water for drinking and a couple of 5 gal plastic containers filled with water for washing dishes, hand washing, etc. Fill a 1-2 gallon plastic pail with water in the bathroom for flushing the toilet instead using water from the FW tank and the pump.

Keep the showers short - aka Navy showers.

Get another 25-50 feet of hose so you can replenish water used in the FW tank.

Good luck - hope it all works out for you and the kids.

[Sarvi]

After 2 days, my batteries are down to 1/3 Luckily I'm only about 45 mins from home so getting my generator. We have not used any lights, the only thing powered on is the water pump. So I'm guessing it's not gonna last 2 more days.

[SteveC7010]

Originally Posted by Sarvi

After 2 days, my batteries are down to 1/3 Luckily I'm only about 45 mins from home so getting my generator. We have not used any lights, the only thing powered on is the water pump. So I'm guessing it's not gonna last 2 more days.

The pump is not the only thing that is "on." The propane detector, refrigerator, and the entertainment center all pull current constantly. You can remove the fuse for the entertainment center. Disconnecting the propane detector is a personal decision. Unless you choose not to use the fridge, you have to leave it connected. If you have a charger for a cellphone plugged into 12vdc, it may also be drawing current 24/7 especially a usb adapter.

There may be more "vampires" in your rig. You'll have to find them and remove or disconnect them.

Dry camping requires a much different approach to rv living.

[Sarvi]

I looked at the manual for my refrigerator, and I'm pretty sure it's electric/propane, no dc. I unplugged the television so the standby light turned off. I did actually attempt to charge my phone once, but it wouldn't charge, the phone didn't even detect that it was plugged in. I didn't leave the charger plugged in after I realized it wouldn't do any good. A grand total of 4 showers were taken, 2 of them with the generator running.

I picked up my generator on Saturday, it's a 5000W Honda, ran it for 5 hours and the batteries charged up 1/3. By the time I was packing up Sunday morning, indicator showed E. I BARELY got the slideout back in.

I was very disappointed with the life of the batteries.

[Festus2]

Try checking your fridge to see if it has a "Climate Control Switch" which is in the ON position. Some Dometic fridges have such a feature to control the moisture level inside the fridge. The switch is a small, black rocker type located underneath the fridge control panel at the top. You might have to open the fridge door and stoop over to see it.
If you do have such a switch and it has been left ON while unplugged from shore power, it will drain your battery down in a hurry.

Also, if your batteries aren't being charged, the converter may be the culprit.

When using the generator to charge the batteries, was it plugged into the RV or did you use the generator's 12V outlet and hook it up directly to the batteries?

[JRTJH]

Originally Posted by Sarvi

I looked at the manual for my refrigerator, and I'm pretty sure it's electric/propane, no dc. I unplugged the television so the standby light turned off. I did actually attempt to charge my phone once, but it wouldn't charge, the phone didn't even detect that it was plugged in. I didn't leave the charger plugged in after I realized it wouldn't do any good. A grand total of 4 showers were taken, 2 of them with the generator running.

I picked up my generator on Saturday, it's a 5000W Honda, ran it for 5 hours and the batteries charged up 1/3. By the time I was packing up Sunday morning, indicator showed E. I BARELY got the slideout back in.

I was very disappointed with the life of the batteries.

The refrigerator has a "control board" in the overhead panel and a control board mounted to the rear of the refrigerator. Those boards are 12 VDC as well as the internal light and on most refrigerators, a 12 VDC heater circuit built into the door frame of the refrigerator that helps prevent frost buildup on humid days. As for the TV, unplugging it (if it's an AC TV) won't do anything to help conserve battery power, however, there is a small "pin switch" on the Winegard amplifier that will turn off the 12 VDC antenna amplifier power (conserving battery power).

There are a number of "parasitic drains" on your batteries that you simply can't stop from draining your batteries (unless you disconnect them). Those include the propane detector, the "memory circuit/backlight on the stereo, in many RV's, the CO detector, and yes, even the converter uses "hidden power" in that it has a cooling fan that comes on when you turn on the lights or other 12 volt items and increase the 12 VDC consumption above a specific level. That fan is there to cool the transformer and electrical components inside the converter, it doesn't do anything to "help" conserve battery power for your appliances and/or lights.

All told, even with "very conservative use" most people with two 12 VDC batteries will need LED lighting, limited use of the stereo, virtually no use of the TV amplifier, limited use of the vent fans, and even then, usually only get 2 or 3 days before they must recharge their batteries. Keep in mind that the slides draw a "TREMENDOUS" amount of battery power, so if you start with "fully charged batteries, set up at your site, unplug your tow vehicle, level your trailer and then deploy your slides, you've used "probably" half to a full day's battery power, just to open the slides.

The answer? Upgrade to LED lighting, mod your refrigerator "door heater circuit" (see how in a thread on this forum), disconnect as many parasitic drains as you're comfortable doing without, use your tow vehicle to help recharge your batteries during slide deployment, and use your generator to help keep batteries charged. Consider upgrading your batteries as well, either to larger 12 Volt ones or to a 6 Volt system.

Keep in mind that discharging 12 VDC Deep Cycle batteries beyond 50% charge repeatedly will shorten their lifespan significantly. Allowing them to discharge down to 1/3 power will surely cause them to fail to hold a charge if you do that repeatedly.

There is no "good answer" to how to "dry camp" with batteries unless you make some significant changes in power use and install components that use less power as well.

Good Luck

[Sarvi]

I will look for such a switch. Thank you for mentioning that!

I plugged the RV shore power cord into the generator.