RV Batteries Die Very Quick

[elib]

Hello, new to this group! We purchased our first TT a few months ago and it came with a Go Power solar panel on the roof and a battery info panel mounted inside the trailer. We just boondocked for the fist time last week and noticed the batteries would die within a few hours. It came with one battery but I had the dealer add a second battery when we purchased it in hopes of being able to go boondock for longer periods of time. The batteries will show fully charged after a day of driving but when we park and get setup that afternoon the batteries are basically dead by the time we go to bed. The fridge is a 12v all electric fridge so it's pulling some power but other than that all we used was a couple of the LED lights for a few minutes and the water pump for maybe a couple minutes. The next day when the sun comes up the solar panel starts charging the batteries but they never really get above half full even with full sun all day. If I plug the trailer into my generator or tow vehicle the battery monitor will instantly show the batteries as full. If we go to bed with batteries showing full they are dead by morning. It seems like 2 batteries should last longer than that? I could definitely be doing something wrong as well. Anybody have any advice on this?

[RedRoverComeOver]

More questions than answers but could help with something that may have been overlooked.

Is the second battery matching? Did they install in series or parallel? How high do you have the fridge set at? Is the fridge dual compartment with separate controls? Do you have an external fridge that's not being used and on?

Are you using 110V? If not, turning off the inverter helps reduce draw even though you're not actively using it. Is water heater on and set to DC? Are water tank heaters on? Which solar panel is it, 100 or 190W?

[Bama Rambler]

Yours is a typical story. There a few things going on here.
That 12 volt compressor fridge is a power hog for boondocking. It'll drain the batteries pretty quickly.
You likely have group 24 batteries which are not true deep cycle batteries. So your total amp-hour isn't very large.
It appears that you're using the monitor lights to check the battery charge. You really need a multimeter and be able to 'rest' the batteries before testing charge level.

Any time you're hooked to external power (TV, shore power, generator, etc.) the monitor lights are always going to show full, because it's reading the charge voltage and not the actual battery voltage.

Let us know which batteries you have and if you have a multimeter.

[bikendan]

elib, you need to tell us what size solar panel and what kind of batteriesyouhave. I'm guessing it's not sufficient for your needs.
We dry camp and boondock quite a bit and prefer our Honda 2000i inverter generator, over a solar panel.
Many of those who have a 12v fridge, have moved up to LiPo batteries and bigger solar panels.
My Honda cost 1/2 of what a LiPo battery costs.
Also the cheap battery monitor will always show full, if the trailer is plugged into shore power, generator or tow vehicle.
You need a better battery monitor or a multimeter for testing the batteries when not connected to a power source.

[JJaxon]

Lots of unknowns here. 2 batteries, what type and size? How are they wired? Solar panel size in watts? Your fridge is electric only, not ideal for boondocking. It will consume more power than one panel can produce. It gets worse if your fridge is in a slide and the sun hits that side as you set up. Most rvs don't come with enough solar to boondock, regardless what a sales person tells you. Do a legitimate solar audit to determine the usage of all appliances that draw, including Co2 detector, microwave, fridge,furnace fan, fireplace, all 12v equipment. Then, start building a solar array that fits that need. Don't think you can run air conditioner on solar, it's just a bad idea unless you get 1200 watts or more of solar, and 600ah of batteries.

[Larry-NC]

My understanding, possibly incorrect, is that these units come with about half as much solar power as they really need. Your suggestion that the batteries are only restored to 50% charge supports that.

The closer the battery(s) get to full charge, the slower they charge. If you double the solar charging (e.g., add a second panel), you won't go from 50% to 100%, but maybe 50% to 80%. But if you get back to 80% every evening it's sustainable, unless you get cloudy days.

[Tom48]

Let me offer a few suggestions from my first modern trailer.

As said above, don't be fooled by what the idiot lights tell you. First of all when it's charging it will look like it's full. Second of all full is a questionable term. The idiot lights may say it's full when the battery is not really fully charged..

My first few outings in a "modern trailer" had me not fully charging the batteries to begin with because my brain thought plug it in before you go to bed and when you get up in the morning they will be topped off. That was never the case. Badly discharged batteries, even a pair of group 24 batteries which is minimal, can take days to fully charge with the onboard charger that comes in most trailers. A massively high use appliance like a 12 volt refrigerator is pretty much geared to people that are going to go out and be on hookups.

If this is a new Forest River product, my suspicion is that you have a 200 watt panel and a go power 30 amp charge controller. When we had our new Forest River trailer we doubled that solar and then took the group 24 batteries out put in two of the best golf cart batteries I could get my hands on. Even then if I pulled those batteries down real deeply with with the TV in the direct Tv receiver I could wake up with some pretty weak batteries and I had a gas refrigerator.

The secret is more batteries and more solar, until then I agree a little Honda generator doesn't make much noise if you block it particularly well from your campsite and it'll definitely run your coach while the solar tries to charge the batteries for the quiet hours. If you are thinking more solar and maybe lithium in the long run then the harbor freight knock off of a Honda generator will still meet your needs and probably last as long as you need it to, for a lot less money

Finally never depend on the hook up through the seven-pin connector on your truck to charge your batteries. At best with the solar and the standard 7 pin hookup you might be putting in as much as the refrigerator is drawing out but very little if any more.

Best of luck as you learn the fine art of battery management and dry camping.

[Flybob]

One thing to check and one important point.
Check to insure that your breakaway switch pin is not pulled. That will kill a battery in no time.


Any time you are charging the batteries either by TV (truck) , Shore power using converter, generator or solar the batteries will show full charge as the gauge measures battery voltage and when charging the voltage at the terminals is at or above full charge.

[Trawlerphil]

I had 8 golf cart batteries on my boat when I was living aboard and I still had to run my 7500 watt diesel generator one hour in the morning and one hour at night to keep a little Sears apartment sized refrigerator/freezer happy and that was with a 140AMP inverter/charger.

The good news is it is a spreadsheet exercise. Write down the watts required for each device and how long you use it every day and you'll have an estimate of how much battery capacity you need. Plan to recharge before you hit 20%.

[Bob2019]

In recent MH or trailers, it doesn't take much to draw down the batteries. In mine, I have two electric slides, TV, DVD, lots of lights, three floor lights on at night (gotta have on to avoid a bad fall in pitch black night), electronic boards to run the refrigerator (Gas & electric), water heater, Propane gas detector, electric awning, water pump, One Control touch screens, Wi-Fi to run the One Control from your phone, the vent fans, and there may be others I have missed. All this stuff takes lots of battery power unless you are hooked up to electric. It is a fact of RVs these days. If you have a 12v refrigerator, or run the furnace fan, you may be dead in a day.

I just installed a Victron Smart-Shunt to see what the state of charge my batteries are and how many amp-hours used. Very useful and allows me to manage battery use. Costs $130.00 and will let me know to avoid going below a 50% discharge state. Below 50% and you shorten the life of your batteries. Batteries are not cheap. Not only that, but have weak batterie(s) and you may have a hard time bringing in those slides.

[TitanMike]

Originally Posted by Bob2019

In recent MH or trailers, it doesn't take much to draw down the batteries. In mine, I have two electric slides, TV, DVD, lots of lights, three floor lights on at night (gotta have on to avoid a bad fall in pitch black night), electronic boards to run the refrigerator (Gas & electric), water heater, Propane gas detector, electric awning, water pump, One Control touch screens, Wi-Fi to run the One Control from your phone, the vent fans, and there may be others I have missed. All this stuff takes lots of battery power unless you are hooked up to electric. It is a fact of RVs these days. If you have a 12v refrigerator, or run the furnace fan, you may be dead in a day.



I just installed a Victron Smart-Shunt to see what the state of charge my batteries are and how many amp-hours used. Very useful and allows me to manage battery use. Costs $130.00 and will let me know to avoid going below a 50% discharge state. Below 50% and you shorten the life of your batteries. Batteries are not cheap. Not only that, but have weak batterie(s) and you may have a hard time bringing in those slides.

The Victron battery monitor is a lifesaver if you need to rely on batteries for essentials.

The LED gauges give a false sense of security, making one think they've charged the batteries after an hour or two of running a generator.

Even smaller 100 ah battery banks only discharged to 50% will take more than a couple hours to achieve a FULL charge.

Only a battery monitor using a shunt, with properly configured electronics, will tell one when the battery has been fully charged. That is unless you wait hours with no charging or load to check voltage or use a hydrometer (Not possible on AGM's).

[Chuck_S]

Unfortunately it seems few folks research sites like this until after they've spend the money on a camper.

The battery the dealer includes only meets the legal requirements for the break-away brakes on the trailer and a couple of lights for a couple of hours until connected to shore power.

Back before LED interior lighting camper batteries often didn't last the night when dry camping. Since then the battery lasts much longer -- until some accoutant decided it was a "good idea" for the bottom line to stop fitting LP refrigerators and rely on less expensive and dirt simple to install 12vDC units which are properly termed battery predators -- yep, they eat batteries. But the minimum wage assemblers only have to stick them in an alcove and plug them in. No gas line to run, no outside air intake and exhaust, etc.

Off grid camping without hassles requires lots of battery power, a system to keep track of the amphours remaining in the battery, and a good charging system. None of these come with any camper I'm aware of. A pair of "golf cart" batteries is the minimum price of admission. A 1000w generator is several times more efficient than a solar charging system that doesn't exceed the square footage of the roof. Trimetric or other monitoring system to know the state of the batteries.

-- Chuck

[elib]

Thank you everyone for the replies and advice! I quickly realized I didn't provide a lot of important info.

The batteries are the exact same, group 24, they say 75Ah, wired in parallel so that should mean 150Ah. From what I can tell online the solar panel is an 80W, which I'm guessing is way too small to effectively charge the batteries. I'm positive the dealer installed the cheapest batteries possible too.....finding out RV dealers and their service techs aren't the best! The same guy who installed the 2nd battery on our TT also installed my hitch completely wrong which I had to reinstall myself, so I should verify the batteries are all connected properly.

I do have a multimeter and fairly competent when it comes to electrical (more so AC but learning more and more about DC). My mulitmeter reads within 0.10v of what the Go Power solar battery monitor says in the trailer. That makes sense what y'all said about that monitor reading full batteries when plugged into shore power or generator though.

Great suggestion on going through each electrical device and calculating watts used in order to see if upgrading the solar/batteries makes sense. It does make sense though that the 12v fridge would be a huge battery suck.

I have a 4500w inverter generator that easily runs everything including the AC, but I guess I was just hopeful that I wouldn't have to use it everyday if boondocking.

Overall sounds like it's not a defect with the solar/battery system, just that it's too small. I definitely need to do more research on battery management and how much power we use on average while boondocking.

[NJKris]

Sounds like you have 2 cheap 'starting' batteries, not true deep cycle batts, in which case you only want to go down to 60% SOC (deep cycle batts will last a long time with 50% SOC, but CAN even go to 20%, so long as you recharge fully right after). So, if you have 150 Ah hours total, you don't want to go below 50% SOC, which is only 75 amp hours available to you. As I mentioned, you don't even want to go that low if they are not true deep cycle batts, like golf cart batt. I'm guessing you fridge has been deep draining those batts, which will make them worse and worse.