Parasitic draws, solar and boondocking

[Stryker Guy]

I am trying to shutdown the parasitic draws in my trailer (T251SSXL). They should be similar to other trailers. I find we get 3-4 days on the battery even with a 100w solar panel. We are very stingy with lights and turn the water pump off when not in use. Right now, I resort to turning off the battery disconnect so the trailer doesn't suck power during the day. I know the radio, CO2 detector and fridge need some battery but it seems odd they would draw so much. Any other thoughts?

[wharfrat48]

How are you defining "so much" energy draw? Everything depends on the capacity of your battery bank, your energy usage, and the amount of re-charge from your panel (or anywhere else).

[TacomaJoe]

My parasites eat about 18Ah per day. My original battery was rated at 65Ah and would give me 35Ah before getting to the danger zone for discharge. That's using no DC for lights, pumps etc. I have a battery monitor so that I can see how much the solar is putting in and how much I'm taking out.

[Reverse_snowbird]

Turning off the battery using the battery disconnect inside the rig does not eliminate parasitic loads.
What kind of refrigerator do you have?

[Rhumblefish]

It's /ALL/ about how fast you make electricity, how much you can store, and how fast you consume it. You've decided to approach the problem from a consumption standpoint... but the other two factors are important, too.

You're boondocking on 100w of solar (which is next to nothing).
How big and what chemistry/style is your battery bank?
If you've got a 12v fridge, that's the big draw. Frankly, I'd be surprised you'd get 3-4 days.

For boondocking, you likely need to double (if not triple) your solar, and maybe consider more battery (a 100ah LiFePo for $375 would cure a lot of evils). Solar-on-the-side (with controller built in) can push watts straight into your battery, or more panels on the roof.

[nvs4602]

100 watts of solar is good for keeping your battery charged while in storage but not much help during use. More solar would be a plus.

You should buy a shunt meter either the expensive vitron shunt meter or the cheaper AiLi shunt meter, both can be found on Amazon. Then you'll know how much draw or charge your batteries are seeing.

I too see about 18ah of parasitic draw on my battery per day when in storage. You have to put a disconnect on the battery itself to completely stop all parasitic draw.

Here aer a couple pictures of the AiLi meter I installed in my motorhome. In the picture, the shunt for the meter is fastened to the wall next to my lifepo4 battery.

[jimmoore13]

Originally Posted by TacomaJoe

My parasites eat about 18Ah per day. My original battery was rated at 65Ah and would give me 35Ah before getting to the danger zone for discharge. That's using no DC for lights, pumps etc. I have a battery monitor so that I can see how much the solar is putting in and how much I'm taking out.

Parasitic loads should top out at roughly 3 AH per day - 0.125 amps per hour. If you have 18 AH of "parasitic" loads, something is wrong.

A typical group 24 FCLA should be able to support parasitic loads for 10 to 12 days before needing to be recharged.

[jimmoore13]

Originally Posted by nvs4602

100 watts of solar is good for keeping your battery charged while in storage but not much help during use. More solar would be a plus.

You should buy a shunt meter either the expensive vitron shunt meter or the cheaper AiLi shunt meter, both can be found on Amazon. Then you'll know how much draw or charge your batteries are seeing.

I too see about 18ah of parasitic draw on my battery per day when in storage. You have to put a disconnect on the battery itself to completely stop all parasitic draw.

Here aer a couple pictures of the AiLi meter I installed in my motorhome. In the picture, the shunt for the meter is fastened to the wall next to my lifepo4 battery.

IMPORTANT CAVEAT: this was in sunny Colorado.
I could boondock indefinitely with 100 watts of solar, a group 24, and very frugal use of power. Uses included propane fridge, hot water heater, pump, furnace (about 5 amps in a PUP running at about a 30% duty cycle), parasitics, rare use of lights (used portable LED lanterns and a propane mantle lantern). BUT, we also had an inverter to run the electric blanket for about 15-20 minutes to take the chill off the bed...about a 30 amp load totalling 8 to 10 AH.

We had a generator, and we ONLY ran it to make lattes (microwave to preheat the milk and steam espresso machine), because we are not savages. The genny would run as much as 20 minutes each morning and evening, and in the morning, at bulk charge rate, we might have pushed 3 to 5 AH into the battery during the process. The converter fan would run. In the evening, the battery was so full that the converter fan didn't run, so the genny provided little charge.

So it depends where you camp. 100 watts of solar can keep a group 24 fully charged if you have good sun.

[sdelam]

Other than the fridge, the largest parasitic load I found was the radio. Even turned off, the standby mode used a over .5 amp. I put a rocker switch in line with the power wire and can kill it completely now.

[jimmoore13]

Originally Posted by Stryker Guy

I am trying to shutdown the parasitic draws in my trailer (T251SSXL). They should be similar to other trailers. I find we get 3-4 days on the battery even with a 100w solar panel. We are very stingy with lights and turn the water pump off when not in use. Right now, I resort to turning off the battery disconnect so the trailer doesn't suck power during the day. I know the radio, CO2 detector and fridge need some battery but it seems odd they would draw so much. Any other thoughts?

Depending on how your solar is connected, using the battery disconnect may disconnect your solar from the battery. This could be part of your problem.

As others mentioned, the roughly 3 AH per day consumed by the parasitic loads cannot be disconnected without actually removing the cables from the battery. They do not draw through the battery disconnect switch...FOR A REASON: SAFETY.

You MUST have your CO and propane alarm functioning for safety. You MUST have your brakes' battery supply in case the rig comes loose during a tow.

Make sure your solar is actually charging the battery. Check the voltage in full sun...it should show in the high 13s or low 14s. If not, figure out why the solar isn't doing its job.

You didn't mention your fridge. Hopefully you have a two-way absorption fridge (120 volts and propane). If you have a 12 volt compressor fridge, what's below must be amplified more to account for the roughly 35 AH the compressor fridge eats daily.

Also, you don't say where you are. 100 watts of solar and a group 24 battery (what you have) is fine for frugal campers in sunny Colorado. But if you are in an area that is cloudy or hazy, you need more solar...and probably need more battery if you boondock. Furthermore, this is a LOT of RV to run on 100 watts/group 24. I did that with a popup. But your furnace alone draws at least 10 amps when running. You NEED more juice if you intend to boondock and not listen to your generator run all day.

For comparison only: I boondock exclusively...in Colorado. CO is both sunny, and the altitude's thin air also helps with solar gain. My rig, smaller than yours, is equipped with 400 watts of solar and a basic battery system: 2 by 6-volt golf cart batteries (GC2s) rated for 115 USABLE AH (230 total amp hours). When I did this setup...spring 2020...the selection of inexpensive LiFePo4 batteries was sparse, and they didn't have much of a track record. Battleborns were about a kilobuck a pop, so they were out of the question. Today I'd rethink my battery choice and go LiFePo4 from Amazon. You get to use about 80% of these vs. 50% of FCLA, and they are much lighter. All told, I paid about $400 (including core charges) for my GC2s, and they weigh a ton...close to 90 pounds each.

But I NEVER run out of power. We are frugal, but we do run the stereo, lights, awning in and out (often on windy days), the slide, and so on. Our ONLY limitation on length of stay is the black tank. We stretch that with a portable dump tank, but that doesn't get us much. The liquids drain and the solids sit, because we are frugal with water when boondocking. Without a garden hose down the toilet to assist, the tank doesn't drain all that well. But I digress.

If you boondock I suggest:
Solar Wire the solar directly to the battery bank, and it will work all the time no matter the status of your battery disconnect switch.

And I provided a link to batteries. You could plug in a 200 AH LiFePo4 that would give you 160 usable AH, and, in decent sun, the solar - perhaps with some help from a generator on grey/rainy days - would keep you going for a long time.

My rigs below. 100 watts on the PUP. 400 watts on the hard side.

[nvs4602]

Originally Posted by sdelam

Other than the fridge, the largest parasitic load I found was the radio. Even turned off, the standby mode used a over .5 amp. I put a rocker switch in line with the power wire and can kill it completely now.

I haven't had time to track down what's draining my battery yet. But didn't realize how much I had until I put the shunt meter in. And it will be easier to find with the meter than it would have been without it.

[fipntdot]

Make sure the television amplified antenna (if you have one) is off. Do you have usb plugs? Ours has several and every one has a light that is always on. Not sure how much they draw on standby. Might be interesting to see if they can be shut down when not needed.

[richp]

Originally Posted by sdelam

Other than the fridge, the largest parasitic load I found was the radio. Even turned off, the standby mode used a over .5 amp. I put a rocker switch in line with the power wire and can kill it completely now.

I did this as well - a simple and effective move.

[awellis3]

Originally Posted by sdelam

Other than the fridge, the largest parasitic load I found was the radio. Even turned off, the standby mode used a over .5 amp. I put a rocker switch in line with the power wire and can kill it completely now.

My biggest load is the wardrobe slide.

[Chuck_S]

The slide constantly draws power?

-- Chuck

[Chuck_S]

Typical RV battery "amp hours" are grossly overstated. An 80 amphour battery is lucky to provide 55 amphours under less than perfect conditions. These are typically "dual power" "Marine" batteries and not true (or even partial) deep cycle. Milliamps add up quickly when connected 24/7.

RV battery use and maintenance is one of the Camper Big Two ancillary hobbies. The other is, of course, sewage.

-- Chuck

[SacRV]

First off, 100w solar panel is not going to generate much. You will only get 80-90% efficiency for maybe 4-5 hours a day if out in the open. Our trailer pulls 10-15w of D/C alone.

[nvs4602]

Thanks for the TV amplifier tip. I forgot all about it. The switch is on the ceiling so it's out of sight.

[mnoland30]

We have a 100 watt on the roof and a mobile 100 watt panel that we can aim at the sun. We don't use our heater much (sleeping bags) and are careful with our use. Most days our dual 6v golf cart batteries don't go below 80%. We don't ever run out of power, water is our biggest issue. I carry 50 gallons extra in the back of the truck. I don't worry much about parasitic loads. I did put a switch on the radio, since we never camp where there is reception.

[RollingDoghouse]

Man, I am taking notes on this thread. Thx everyone.
I just picked up a 2014 Sunseeker and intend to mostly be boondocking. I found my batteries down in just a few days when I thought everything was off. Much to learn!