Parasitic draws, solar and boondocking

[chriscowles]

Originally Posted by 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.

You can replace the cheesy OEM USB chargers with higher-powered versions that have a shutoff button. Alternatively, replace all USB chargers with 12V accessory sockets, which are more versatile. Plug in the 12V USB charger of your choice, when and where you need it; unplug it when you don't.

60W USB C Car Charger Socket
https://smile.amazon.com/dp/B092M6S98V

[Reverse_snowbird]

Originally Posted by 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!

Welcome RollingDoghouse.
If you're boondocking, your onboard generator will be your most reliable source of power. Most are set to turn off if you get to 1/4 tank of gas to give you enough gas to drive for a refill. You don't want to run your batteries down and shorten their life.
Many people buy solar panels or solar generators to keep their batteries charged if they camp in sunny areas.

[Tom48]

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.

Nice clean little install! I find it near impossible to keep my three home built LiFePo batteries tidy. Wish I had room for the custom boxes.

[Stryker Guy]

Battery is a 120ah group 31. Disconnect is on the tongue between the battery and the trailer

[TitanMike]

Originally Posted by 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

Even if a Lead/Acid battery left the factory with the state Amp Hour Capacity, that's the last time it will ever contain that much energy. Over time the capacity will diminish to the point it will be considered useless. This is exacerbated by not recharging ASAP after a discharge.

A battery that left the factory with a rating of 85 ah may have had a year of shelf time before it got into the hands of the consumer. A couple seasons later it's really a "three year old battery which for many is "Senior Citizen Status".

[Stryker Guy]

Originally Posted by Stryker Guy

Battery is a 120ah group 31. Disconnect is on the tongue between the battery and the trailer

Also forgot to add, the fridge is 120vac or propane. When I use the battery disconnect, everything in the trailer including the CO2, radio and fridge are off. We do not occupy the trailer in this state so there are not safety issues. Smoke alarm is 9v battery powered.

Solar is connected direct to the battery to minimize losses.

I would just like to eliminate or reduce the parasitic draws with the exception of the fridge and CO2.

I will be putting a disconnect on the stereo. That is a great idea.

[Tom48]

Originally Posted by jimmoore13

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.

I concur. ALTHOUGH I think you give GR- 24 batteries too much credit. I hope he means static load when in use, like propane frig on, alarms on and probable parasitic draw of radio/DVD player, and even at that there may be something else in the mix.

[Tom48]

Originally Posted by Stryker Guy

Battery is a 120ah group 31. Disconnect is on the tongue between the battery and the trailer

Maybe that GR-31 battery is not giving you that stated level of capacity. Wet batteries decline from new pretty fast. For a basic wet cel battery I don't think you can beat two high quality GC2 batteries.

[Stryker Guy]

Originally Posted by Tom48

Maybe that GR-31 battery is not giving you that stated level of capacity. Wet batteries decline from new pretty fast. For a basic wet cel battery I don't think you can beat two high quality GC2 batteries.

I agree and would go to two 6v but I cannot add the tongue weight.

[Chuck_S]

A rule of thumb that's worked well for me for years is

Useful Amphours = Reserve Capacity / 2.4

My pair of Trojan T145 batteries has a RC of 530 minutes. 530/2.4=220.8 Useful Ah
A typical "80 amphour" Group 24 battery with an RC of 130 minutes: 130/2.4=54.1 UAh

-- Chuck

[Tom48]

Originally Posted by Stryker Guy

I agree and would go to two 6v but I cannot add the tongue weight.

Might be time to look at Amazon's offering of LiFePo batteries. 200 amps with a full 200 amp BMS is about 48 lbs. 200 amps with 100 amp flow BMS is less expensive and maybe a smidge lighter.

If I hadn't built my 3 200 amp batterie, each with full 200 amp BMS from Chinese parts , two years ago, I would be looking at the AmperTime offering on Amazon. Store bought from decent brands, AmperTime, Chinn ? Is less or the same as I invested in parts two years ago.

[Stryker Guy]

Originally Posted by Chuck_S

A rule of thumb that's worked well for me for years is

Useful Amphours = Reserve Capacity / 2.4

My pair of Trojan T145 batteries has a RC of 530 minutes. 530/2.4=220.8 Useful Ah
A typical "80 amphour" Group 24 battery with an RC of 130 minutes: 130/2.4=54.1 UAh

-- Chuck

How do you come up with the RC number?

[Captbill]

Double check your wiring to your main on/off switch.
I was having a problem with my new Astoria 5th wheel. With my main power switch off, my battery was still draining even with a solar trickle charger connected. I did a closer examination of the wiring and discovered several feeds such as the Lippert auto level still powered with the switch in the off position.
I redid the wiring, now all thru the switch and no more drain.

[80 Cruiser Rod]

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?

Much of what you listed is accurate but know one thing, while you are camping w/o electric using your radio is a tremendous drain on whatever energy you're drawing from. When I camp w/o electric I bring my bluetooth speaker and never use the radio. Re-charging the speaker uses a minimal amount of energy compared to a radio or head unit. If you have decent sun light and a 100w solar panel you shouldn't have any problem.

The most common parasitic draw will come from your TV antenna booster.

[Midwest Ed]

Originally Posted by Stryker Guy

How do you come up with the RC number?

The "Reserve Capacity" is specified by the manufacturer of the battery. It specifies the number of minutes of use at a fixed load in amps. For my Interstate 6 volt batteries it is 562 minutes at 25 amps. The Amp-Hour rating is specified at a fixed time. For mine it is 251 Amp-Hours at 20 hours.

Reserve Capacity is not published (or hard to find) for some types of batteries, especially for ones that are not considered "deep cycle".

I'm not sure where Chuck_S came up with 2.4 but I'm guessing it is simply experience. For me, 562/2.4 = 234 Amp-Hours. I'm not sure if all manufacturers use the same load of 25 amps for reserve capacity although 234 seems reasonable as manufacturer's ratings are always optimistic and measured under ideal and new conditions.

[tnlyne]

If you have a multi-meter you can put it into current measuring mode and go to your camper's fuse box. Start pulling out one leg of the fuse and put your meter inline with the other leg and you can measure the parasitic loads on each zone. I did that and found my "trouble" circuits (like the radio) and then just pulled those fuses to reduce parasitic loads. This worked well for a while but I got tired of pulling fuses out and putting them back later. So, I instead put in a batter disconnect switch at the battery box and have used that since.

[Midwest Ed]

Originally Posted by tnlyne

If you have a multi-meter you can put it into current measuring mode and go to your camper's fuse box. Start pulling out one leg of the fuse and put your meter inline with the other leg and you can measure the parasitic loads on each zone. I did that and found my "trouble" circuits (like the radio) and then just pulled those fuses to reduce parasitic loads. This worked well for a while but I got tired of pulling fuses out and putting them back later. So, I instead put in a batter disconnect switch at the battery box and have used that since.

It's also wise to not use fuses as repetitive "on/off switches". As a troubleshooting aide this is fine but the fuse sockets are not designed for even multiple dozens of insertion cycles that will eventually result in the need to replace or repair the circuit board.

Also, be aware most multimeters in the current measurement mode are typically rated for just 10 amps (or less sometimes). Obviously, when the actual load is the low "parasitic" current draw region this will not be a problem but an "accidental" measurement could blow the fuse in the meter.

[Papadave]

Radio and antenna are easy fixes. One problem with disconnecting the battery is it will cut off the power to the propane solenoids. Your propane fridge won’t work. I did an audit you can find here:

https://www.forestriverforums.com/fo...it-247712.html

[Eric H.]

We survived for years with a single 85w panel and 2 group 31 100ah AGM batteries. We could go for 9 days in the Northern California Sierras with partial tree coverage and conservative power usage. That was with fridge and water heater on propane, 25' TT. Never shut off the water pump but that only runs when you need it anyway. Our trailer was mainly to keep food cold and sleep in though so all drinks were in a cooler and all cooking is done out doors. We eventually added a couple small fans and started running the radio during the day if we left the dogs for a bit so I added another small panel which did the trick.

Now we have a 5ver with 2600w solar, 550ah LiFePO4 and whole house 3000w inverter with soft starts on 2 A/C's. Plus an onboard 5.5kw Onan.

[MNtraveler]

Originally Posted by jimmoore13

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.

What OP calls "parasitic loads" appears to include the refrigerator. At least, he's trying to eliminate parasitic loads, but the total load he is referring to appears to include the refrigerator, in other words, what his power load is while boondocking. Also I assume it includes the water pump when used even though he leaves it off when not in use (iffy power savings there...). Perhaps includes control board for water heater even if running on gas.