Battery Dilemma

[rootusrootus]

Cross country camping this July in my fancy new 21BHE. Reservations at mostly full service campgrounds but some nights without water/power. Came with a single 12v battery. Will that be enough juice? Or will we need to be super careful?

Assuming it's the standard Interstate batteries most dealers seem to use (and did you only really get one?!!), then it probably has about 30 usable Ah, maybe a little bit more. Each light in the trailer. whether ceiling or task light (and for the double-lobe lights, those count as two...) takes just about 5 watts. The outside light a bit more. I don't know about your trailer specifically, but mine draws about 10 watts just sitting, and just about 90 watts if I turn on every light in the trailer. So with every light on, it would drain a single small battery in 4 hours. Lights are very efficient, though. If you run fans, or the furnace, or have a 12V fridge, then the single battery won't last long at all. I'm not seeing that solar is included on the 21BHE, so hopefully they didn't put a 12V fridge in, it would drain a single battery in less than half a day.

If I were in your shoes, I'd probably grab a couple of the Interstate GC2s that Costco sells for $99/ea. They're not going to knock your socks off, but they should last a few years with light usage, and the usable capacity of a pair of them would be about 105 Ah or so, a big bump over a single small battery, and enough to comfortably do a couple of nights of boondocking if you're not too crazy with power usage. Should fit on the tongue no problem, just need the taller GC2 battery boxes and the cables to connect them in series.

[Silas Jr]

Thanks for the info and expertise. I think your estimates are accurate with what I anticipate. No solar or plan to. Buddying up a second battery seems like it’s worth the effort. And it will keep my rotten kids from getting excessively cranky.

[Redapple63]

The Costco gc2’ I bought for my previous RV were over 7 yrs old and still going when I sold it last summer


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[Extreme]

Awesome answer! I totally agree with you GoodOz.

[rootusrootus]

The Costco gc2’ I bought for my previous RV were over 7 yrs old and still going when I sold it last summer

The newer ones have gained a reputation of dying shortly after the warranty expires. They're not really up to Costco standards IMO. They'll probably last a few years if you just use them a few dozen nights a year, but if I were cycling them every day I'd get Trojans instead.

[SolarPoweredRV]

There is a void behind the power center, so I could make something work with a bit of rewiring. I am going to wait and see if the Lithium charger meant for the power center comes available before our first weeklong trip in April. If not, it will be plan B.

Progressive Dynamics makes a Converter that will slide into the space left by your WFCO Converter. Some say the Progressive Dynamics is a better Converter than the WFCO, I would prefer the Progressive Dynamics Converter if I needed a replacement Converter.

[Redapple63]

Progressive Dynamics makes a Converter that will slide into the space left by your WFCO Converter. Some say the Progressive Dynamics is a better Converter than the WFCO, I would prefer the Progressive Dynamics Converter if I needed a replacement Converter.

Agree. You can gat a deck mounted converter to just screw into the wall of that void.


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[SolarPoweredRV]

Hello all! So, my deep cycle battery that came with my Imagine trailer is shot and needs to be replaced. I am just really torn on what to replace it with.

Here is the backstory. My wife and I love to "dry camp" at state and national parks, so most of the time we will not have hookups. We already have an inverter generator and we use that sparingly (usually each morning for less than an hour). Our plan is to eventually go full or half-time, but when we do we will likely upgrade to a 5th wheel. Until then we will be vacation campers/weekend warriors for the next 3-5 years.

I know that Lithium is the best solution, but I am trying to figure out if I can justify the costs for a rig that I will not be keeping long-term and for the only 20 nights or so a year right now that we don't have power. Since I already have a generator I am not really looking for a solution that can use an inverter to power the 120V side of the rig either.

Here are the options I am looking at:

Option 1 - New deep cycle battery (or batteries) and likely a new 4-stage charger to improve the charging speed and life out of the batteries. This is by far the cheapest option.

Option 2 - (2) new 6V Golf Cart batteries to form a larger 12V battery. We would add a new 4-stage charger as well.

Option 3 - Lithium battery(s) of some sort with the updated charger for it.

If we do decide to spring for the lithium I have the further dilemma of how many and of what size. Can I get away with a single 100ah lithium battery? I think it would be sufficient, but I know that you want to have the batteries be the same age and model if you decide to parallel them, so I really can't add more power later if I find I went too small.

Last question on this - has anyone pulled all their Lithium equipment out and downgraded the camper back to the deep cycle battery setup when they sold their rig? Makes Lithium more palatable if we would plan on keeping it for its entire lifespan even if that meant moving it to a new rig.

What are your thoughts?

Thanks!

First off, if you Love dry camping, you will Love having Lithium batteries onboard. Your problem of your Lead Acid batteries not getting fully charged during your short Generator runs will disappear, Lithium batteries charge much faster.

Secondly, because each Lithium battery has it's own BMS (Battery Management System) you can add another battery to your system later on, the old rule of getting matched batteries do not apply with Lithium.

You are in the perfect position to try out some of the cheaper Lithium battery options available from Amazon. You do not need the battery to last ten years like the Battle Born batteries (10 year warranty). You can buy the cheaper battery from Amazon and purchase an extended warranty if you like, this option should keep your current camper powered up through the end of your time together.

In the post "Cheap Batteries are Coming, Cheap Batteries are Coming" I provided a spreadsheet with the cheapest Lithium batteries I could find (short of building your own battery). Take a look at that spreadsheet to find a low cost solution for your current battery needs. I might also suggest that you take a look at the 200ah Ampere Time battery available from Amazon, at $799 that is a pretty darn good deal !!!!!

Since all of your options include a Converter upgrade, the cost of a new Converter is a moot point.

PS: Please note: in the above post, whenever I mention "Lithium" batteries, I am referring to the LiFePo4 (Lithium Iron Phosphate) batteries and not the Lithium Ion batteries which are found in laptops and Electric Vehicles.

PPS: I did see that you had made the decision to go with the Lithium battery, however, I would still suggest you look at the spreadsheet and consider the 200ah Ampere Time battery.

[SolarPoweredRV]

We are going through the exact same change as the OP is considering. Our reflection 28 bh is rather battery hungry dry camping which we do most of. It loves battery in cold weather ( furnace ) and really loves battery in warm weather (Fridge on propane). The fridge appears to be the worst offender for power use as its mounted in the slide and has FOUR cooling fans in the back, its the bigger 4 door variety to boot so those fans are giving er most of the day on warm days.

We have found that we can really only go dry camping for about 3 to 4 days at our local provincial park using our generators. The parks here have strict time limits on generator use which is understandable and probably a good thing in the long run. Our current battery bank is a set of series 6 volt golf cart deep cycles and eveb with those the limited generator hours cant put enough power back in for extended stays.

We are going to make the switch to lithium iron as soon as the new ones arrive. I have chosen to build my own at this point and have purchased a new charger/converter along with a bms and a monitor system. The cells I am buying will hopefully have about four times my current useable amp hours in roughly the same physical dimensions and less weight.

I am keeping all my stock components in storage and keeping the new battery bank in the stock location in case we decide to sell the rig and wish to return it to lead acid configuration before hand. All I will have to do is get a battery swap it out with my lithiums and swap out the converter for the stock one and it should be back to original.

We love the trailer and the floorplan and probably wouldnt want to change to anything else for the time being but its a terrible dry camping unit for batteries and battery use in stock format.

mike

Mike: Congrats on taking the DIY plunge into LiFePo4 batteries. Your problems with not being able to keep the batteries topped off while dry camping will disappear with the switch to Lithium.

You are correct in that the RV Furnace is a Power Hog, manufacturers should really use a more efficient DC motor in the RV furnaces.

Please document your build process and your sources for the batteries so others will be encouraged to build their own batteries. Building your own LiFePo4 battery is the cheapest option to upgrade your RV battery to Lithium currently available.

[SolarPoweredRV]

Does anyone have a trick to keep your batteries warm during the Winter?
I keep my batteries in the Storage Area for my 2500rl near the distribution water and power area.
Some people use a warming mat in the battery box that is thermostatically controlled to keep their temp above 32 degrees.
What do you use?

Thanks.

Unless you are trying to charge your Lithium batteries below 32 degrees, it really won't hurt them to drop below freezing during storage. The problem comes when you try to charge the LiFePo4 batteries when they are below freezing.