LiFePO4 (Lithium) Battery Build (part 4)

After a few months of running my DIY lithium battery I thought I’d provide an update on it. We used the battery on our 5+ week trip out west, recharging it only via solar. In a few parks we had little to no sunlight during the day (Olympic National Park and North Cascades National Park were particularly deep within the tree canopy). Even still we never used more than 1/3 of the battery capacity during the trip. That was a huge improvement from prior trips where a few days in the shade and cold could result in us draining the lead acid battery down and then needing to break out jumper cables to recharge.

As cold weather is upon us I winterized the camper a couple weeks ago. This seemed like a good opportunity to do a true capacity test, so I pulled the battery off the camper and brought it home. I hooked it up my DC bench power supply and topped it off to 14.6V, then began a very slow capacity test by applying a steady 2A load.

It took almost a week but the test is now complete. The cells I purchased were listed on the Liitokala store on AliExpress as 280Ah. While they had very generic “Liitokala 280Ah” stickers on them when they arrived, they also had official CATL QR codes which said they were 271Ah cells (867 Wh). Upon completing the test, I measured a total of 262Ah of capacity. That’s plenty for my purpose, though it leads me to believe the cells were either used or extremely poor quality as the official capacity is typically determined by running at a relatively high discharge rate (20%, 50%, or even 100%) whereas at 2A I was running at a very low rate (<1%). If my goal was to use these in a high discharge environment like an electric car I suspect they would have about 240Ah of capacity. In our trailer though they work well enough, especially given the cost

LiFePO4 (Lithium) Battery Build (part 3)

In part 2 I talked about my basic 12V setup and how I was top-balancing my new battery cells. I didn’t get into why to top-balance, but there’s an excellent explanation in the DIY Solar Forum – basically each cell is independent and we’re trying to equalize them and maximize the capacity of the pack. I more or less followed Will’s instructions which are also in the forum. However because my cells started out very close to the same voltage (within 0.001V), and my power supply is limited to 10 Amps, I just wired up my BMS and set it to 14.4V/8.5A and let it go. Even still it took ~24 hours to charge, implying the batteries arrived with about 30% charge.

After a few hours of charging…

Eventually the cells start to diverge as they get near the top. Once this happened I re-wired in parallel, set the charger to 3.6V and 8.5A and let it go for the night. (Despite only only needing a few amps, at the top of the charge curve the power supply goes from constant current of 8.5A to constant voltage of 3.6V with a very low Amp rating (1.5A or less).

The last 10A took seemingly forever.

While the cells were charging, I started building the battery box to store (and protect) the cells, as their aluminum enclosures are relatively thin and there are quite a few wires and other electronics required. My goal was to build the main box in such a way that I could “drop” the compression frame with the cells and wiring inside. (Side note: Because LiFePO4 doesn’t tolerate cold, and also I’m not building a IP67 waterproof box, the final battery pack will need to fit inside the trailer in the cabinet underneath the fridge).

The batteries are sit inside a compression frame with the BMS mounted on the right side and a 150A fuse on the left. The frame drops into the box cleanly and applies light pressure to the cells via threaded rod and lock nuts on the ends. An ideal compression frame applies roughly 12psi evenly at all battery states, but the complexity of spring-loading the end plates was too much. Since my battery will stay at 70-90% SOC most of the time I just compressed for that.

Box finished and battery fully charged!

It’s not fancy but since it will be hidden in a cabinet under our fridge, who cares?
Final charge state.

Last step once complete was installation in the camper. I spent quite a bit more time on Sunday than anticipated re-routing the wiring for the solar charge controller and the main battery circuit. However it’s up and running now, with I believe only some minor tuning of the solar charge controller required to limit the battery charging to ~90% in order to extend the battery life.

First trip will be this weekend and we’ll see how it goes!

LiFePO4 (Lithium) Battery Build (part 2)

In my earlier post, I talked about what LiFePO4 batteries were and why I went with them. In this article I’ll cover how I built mine, which should allow most savvy DIYers to more or less repeat the process, building on what I learned. Most of what I learned about LiFePO4 batteries was from the DIY Solar Forum – if you’re truly interested in building your own battery I suggest reading the discussion forum there as well.

One note before I get started – this information is a general overview of what I did, how, and why. However, every battery is different (even LiFePO4, where different manufacturers may use different chemistries to construct their batteries) and every tool is unique. Furthermore, what worked for me might not work for you, and it’s entirely possible I omitted some critical details either accidentally or intentionally (for clarity). If you have no understanding of batteries or electronics and try to follow this step by step and end up blowing up your battery or burning down your house, that is not my fault. Build (and enjoy) at your own risk – part of the fun is learning as you go along.

The largest cost for this project are the battery cells. Right now, decent quality 280Ah cells cost about $100 each from Alibaba or AliExpress, but you’ll need 4, and shipping from China is slow and expensive. Buying cells from China is also a bit risky – some suppliers will buy and re-brand cells, some will sell used cells, and some cells are lower quality (Grade “B” or “C”) or are “unmatched” (very different internal resistance or capacity). Shipping times vary greatly, and not all sellers will do a good job packing your cells so they may arrive damaged. AliExpress (and Alibaba, I think) offer delivery and other buyer guarantees, but in most cases you’ll need to ship the cells back to the seller at your cost to get a refund. Using a credit card with a good buyer protection policy is really important.

4 well-packed batteries arrived

All said I did a little research, but I also got a little lucky with my purchase from the LiitoKala store on AliExpress.

LiitoKala says 280Ah but the QR code says these are 867Wh @ 3.2V which is only 271Ah. I’m not yet sure if CATL de-rates their batteries a bit or if LiitoKala is stretching the truth.

The next major cost is your battery management system (BMS). While it’s technically possible to build a battery without a BMS, it’s generally a terrible idea and you should not do it. A quality BMS will provide a number of critical protections which will prevent you from destroying your very expensive battery cells quickly, including:

  • Low voltage cutoff (<2.5V) to prevent you from draining your battery below 1%.
  • High voltage cutoff (>3.65V) to prevent you from overcharging your cells
  • Temperature cutoff to prevent you from destroying your battery by trying to charge it below 0C or discharge it below ~20C, or conversely from trying to charge or discharge above 55C)
  • Automatic cell balancing, to ensure that all 4 cells keep the same voltage. This will slowly “steal” power from hotter (higher voltage) cells and trickle it to lower voltage cells, which maximizes your cell capacity and performance.

Since my BMS is rated for 120A, I built my battery to handle a continuous load of 120A. While I don’t have a 120V inverter right now, this allows me to add one up to 1500W to my camper at a later date without changing the battery. To handle 120A continuous load, I used three 8 gauge wires or heavy duty busbars for all connections. Note that 10AWG wires can carry up to 40A so three of them should handle 120A, but I believe in engineering a margin of safety into my design so stepping to 8AWG, which can handle 55A, ensures my battery wires will not overheat.

Parts

  • (4) LiFePO4 280Ah cells @ 3.2V (Currently $450 from the LiitoKala store on AliExpress).
  • Overkill Solar 4S 120A BMS. (Overkill buys Xiaoxiang BMS, tests, configures, and re-brands them. I purchased the Xiaoxiang BMS from an eBay seller in the US for $105. You can get them cheaper off AliExpress, but I recommend paying a few extra dollars and buying one from Overkill Solar which has been tested and has a warranty).
  • 150A fuse ($9) as your last line of defense in the event of a short
  • Heat shrink (various sizes) to help protect and strengthen your crimps (about $5)
  • Good quality 8AWG wire. I had some available but if you don’t then just buy a spool. Make sure you get real copper, not copper-clad aluminum (CCA) which has a much higher resistance
  • 8 AWG lugs and 10 AWG lugs for battery terminal crimping. The battery terminals are M6 (6mm) and so 1/4″ battery lugs (6.3mm) will work. I needed six 10AWG lugs just for the BMS as mine came with 10AWG pre-soldered. If you bought the Overkill BMS with M6 terminals you’ll need double the number of lugs, and in that case I recommend using all 8AWG wiring. I use 8AWG for all other internal wiring, which means I needed 12 for the positive wiring as well – three 1/4″ for the positive M6 battery terminal, six 5/16″ for the fuse, and three 3/8″ for the exterior battery stud. Expect to spend about $20 on an assortment of sizes
  • If you go with the Overkill Solar BMS you’ll need 5 ring terminals to wire the leads. I used the red 18-22AWG ones with 1/4″ rings and I soldered the ends to make them thicker since I think the wires are even smaller ~26AWG.
  • Fiberglass strapping tape,($7) which is not strictly required but helpful to secure various things together (like attaching all 4 batteries)
  • External battery studs ($20) to make connecting your RV wiring easy.
  • I ordered a battery box ($15) from noco.com but then learned that you really should put your batteries in a compression frame, so ultimately I built mine out of some 1/4″ and 1/2″ birch plywood. I may still use the lid…
  • Some M6 “grub screws” (aka set screws) for $10, which you can permanently fix in the battery with some Loctite ($5). Throw the screws your battery comes with away – you can’t torque them properly anyway.
  • M6 washers, lock washers, and lock nuts. Home Depot or Ace Hardware have bags of these available. Don’t rely on a nut alone – always use a lock nut and/or lock washer.
  • If you’re building a compression frame, you’ll need some 1/2 plywood and four pieces of 1/4″-20 threaded rod about 18″ long, with 8x washers and lock nuts.

Tools

The following were things required that I didn’t own. If you have this stuff already, then great. If you don’t have screwdrivers, wrenches, a heat gun, and other miscellaneous tools then you’ll probably need to order those too.

  • You’ll need a Variable/Adjustable DC bench power supply in order to top-balance your cells. I bought the 30V/10A version and I’m really glad I did as even this one can take a couple days to fully charge your battery. Technically your BMS will probably be able to top-balance for you but at 30mV or less it could take weeks or months to complete if your cells do not arrive matched, and if they’re really far off it’s possible it might never complete.. If you want to be able to easily balance your battery and to be able to fully charge, then fully discharge, then properly re-charge your cells to confirm their capacity, just spend the $60.
  • A constant current load tester. I used one that runs $15 but you could do this with a 12V lightbulb or a bunch of resistors if you can measure the amperage accurately with a shunt.
  • A reliable multimeter.
  • I recommend a torque wrench designed to measure in/lbs, since if you overtighten your battery terminals you’ll strip them and end up very unhappy. They’re under $20 and often referred to as a “bicycle torque wrench” so you may find other uses for them in the future.
  • A decent wire crimper able to do anything 8 to 22AWG (or better)
  • Decent wire strippers. A heat gun (or aim-n-flame) will help with heat shrink too.

Step 1: Battery Cell Balancing

If you’re patient, the preferred method for doing the initial battery cell balancing is to connect the batteries in parallel (all + on one side, all – on the other), set the bench power supply up, adjust it to 3.6V and max Amps (or really 80% of max, just to preserve the power supply), and let it go until the Amps drops to 0. In fact that’s what I went to do at first. However my cells arrived with 60% charge (which is pretty typical) reading about 3.25V, which means I needed to put 112A in each battery to fully charge them. Even at 10A, that’s 44 hours… and the thing about batteries is that as you get the voltage closer to the current will drop to keep the voltage constant.

Cells wired in parallel in a (temporary) compression frame. If you don’t compress the cells slightly, they may swell.
Power supply set to 3.4V and 8A, but once connected to cells which are 3.3V it switches from a constant 8A current to constant voltage, and the current drops off precipitously.

Rather than let the batteries sit on the charger for days, I decided to wire them in series, set up the BMS, and then apply a ~12V charge to the battery pack. This has the advantage of “only” needing to apply 112A to the pack, so it should take 1/4 the time. My expectation was that the cells were already matched (and probably balanced) within 0.01V so the BMS would take care of any balancing for me.

I set the power supply to 14V (which is 3.5V per cell) and 8A and let it run. Since I’m running through the BMS I suppose could just set it to 14.4V (3.6V per cell) or 14.6V (3.65V per cell) and count on the BMS to manage the cell voltage correctly, but since this is my first top-balance I wanted to give the BMS enough time to be able to balance the cells if they get too far out of whack as the voltage ramps up. I’ll repeat the process at 14.4V (3.6V per cell) once I’m sure the cells are balanced at 14V (3.5V per cell), or I’ll temporarily disconnect the busbars and individually top off a single cell if required.

Basic 12V (4S or “4 battery Series”) wiring
Overkill Solar’s wiring diagram, also available on their website
Cells re-wired in series. and charging much faster now. Eventually once it’s charged I’ll cut down the threaded roads and build a (smaller) permanent battery box.

Stay tuned for part 3

LiFePO4 (Lithium) Battery Build (part 1)

Our camper (travel trailer) has a typical 12V lead acid battery to run most of the devices. Solar does a decent job of keeping the battery topped up, but sometimes we end up in a campsite with a lot of shade and have been finding it increasingly hard to keep the battery sufficiently charged for 4-5 nights. This is particularly pronounced when we get up in higher elevations and will often run the heater at night to keep the temperature tolerable.

We’ve tried AGM batteries in the past but they’re roughly 2x the cost of a regular “wet” cell and don’t really provide much benefit. Honestly just replacing the $99 “deep cycle” battery every couple years has been more cost effective, though it rarely provides any major energy storage benefit. (Except the one time I killed a battery in Big Bend by running too many fans and draining it down to 10.5V overnight…)

I’ve been debating a lithium-based option like the Renogy or Battleborn drop-in LiFePO4 batteries for a while, but at $900 the price is steep for only a bit more capacity. Recently though a friend of mine turned me on to the DIY Solar Forum, where a bunch of people were building their own high capacity lithium batteries for a fraction of the cost. I did the math and decided to make the plunge, which ultimately led me down a rabbit hole in an effort learn everything I could as quickly as possible so I could build and test one before our next long summer trip.

This post has a number of acronyms or terms, which may be used interchangeably at times, even when the meaning isn’t 100% identical. Terms like:

  • SLA = Lead Acid battery (even for wet cell batteries which aren’t sealed). This is probably what’s in your car.
  • AGM = Absorbent Glass Mat battery (it’s like an SLA but actually sealed)
  • LiFePO4 is one of many lithium battery chemistries
  • Lithium Ion = LI = Li-ION or LION, which is a specific battery chemistry, probably in your cell phone
  • Lithium in this post refers to LiFePO4, even though it’s a generic term for all Lithium-based batteries
  • V = Volts
  • Ah = Amp hours. In a 12V battery, 10Ah means you can power a 12V device that draws 10A of current for 1 hour, or 1A of current for 10 hours. I will ignore battery efficient at low/high outputs

If you’re a purist, get over it.

Why Go Lithium?

Cheap lead acid batteries are available at Sam’s Club or Walmart for about $100. My last two Duracell 105Ah batteries came from Sam’s Club. They work, but unless you’re regularly on shore power or run a generator in my experience it’s really hard to get enough capacity from them. This is due to a few reasons.

First, the cheap “deep cycle marine” batteries in my experience are really inferior to high quality deep cycle batteries. I’ve read this is due to thinner plates, the use of recycled materials, etc. I can say from experience though that after two seasons, even with good maintenance practices, these tend to only have 70-80% capacity remaining. High quality AGM deep cycle batteries seem to hold up better over time (except when you completely drain them… d’oh!), but are roughly double the cost at $200-250. Lithium chemistries, on the other hand, are known for lasting thousands of cycles – the typical LiFePO4 battery will still have 80% of its capacity after 2000-3000 cycles, or roughly 7-10 years.

Second, you can use much more of your lithium battery capacity safely. Lead acid batteries should really not be discharged below 50% (though I will go as low as 30% sometimes), whereas lithium can be fully charged and discharged (though the manufacturers recommend keeping and using them in the 10%-90% range. Thus a 100Ah lead acid battery only has maybe 50-70Ah usable, whereas a 100Ah lithium battery is designed for 80% utilization but can be cycled up to 100% if desired.

Third, lithium chemistry batteries weight a LOT less than lead acid. Don’t believe me? Go check your periodic table. That $99 100Ah Duracell is 59lbs, while a 280Ah LiFePO4 battery pack (without the case) is only 50lbs.

So in short I expect given roughly the same space (Group 31 battery size) and weight (60 lbs) to normally have about 4x the usable capacity (230Ah, assuming 10-90% state of charge) vs the old lead acid battery (roughly 60Ah usable). [Note: If I fully cycle the LiFePO4 battery that’s 280Ah, and if I compare that to deep cycling the SLA battery that’s 70 or maybe 80Ah, so I feel the ~4x ratio holds].

Why Not Go Lithium?

There are really only a couple reasons not to do this. The first and most obvious is cost. While the actual cost to build a lithium battery with 4x capacity is on par with purchasing 4 high quality AGM batteries, in practice the latter doesn’t really make sense for me to do because of the weight and space required. (Also because I really don’t *need* more than ~150Ah of lead acid capacity).

The other reason is battery management. LiFePO4 batteries in particular don’t like being charged below freezing or discharged significantly below. In fact, charging your LiFePO4 battery when the cell temperature is below freezing is known to destroy them quickly. To compensate, the battery will need to be relocated inside the trailer and will need a battery management system. More on this in part 2…

Summer Road Trip 2018

The last two summers we’ve done road trips out west, and this year we hooked up the new trailer and went for round three.  Christi wanted to visit Mesa Verde and New Mexico, and I wanted to go four wheeling with the 200 LCDC group again, so from there we started our planning.  Over the last year we decided we’d use our summer trips to try to hit all the US National Parks, which ultimately led us to add Big Bend to the end of our trip.

The LCDC this year was exploring the San Juan National Forest and picked Telluride, CO as the home base.

Boondocking at a rest stop in Nebraska

Days 1 to 3

We left Wednesday afternoon and made it to Cayton Campground about 20 minutes south of Telluride on Thursday evening around dinner time, only stopping overnight at a rest stop in Nebraska.

Cayton Campground

The following morning we met part of the group in Telluride, and decided to set out on the Alpine Loop.  We gassed up and hit the road for Ouray, CO where the trailhead for Mineral Creek starts.

The summit of Engineer Pass

We stopped to air down at the trailhead, then took off into the rocks and shelf roads on the trail up to Engineer Pass.  Half way up Mineral Creek the truck in front of us took a bad line, tried to correct, and ended up with two wheels hanging precariously off the road.  I picked up the radio and relayed that he was “looking a little tippy and ought to stop right now.”  (The next evening I was told I was apparently the king of understatement).  We assessed the situation and ultimately determined that we needed to winch from the front and rear to get him onto stable ground safely.  I got the change to test out my new winch, and about 30 minutes later we were back on the trail.

Animas Forks ghost town

The rest of the day was uneventful.  The Alpine Loop is beautiful, and we had an opportunity to stop at the top of Engineer Pass as well as a few ghost towns along the way to Lake City and across Cinnamon Pass back to Silverton.

Hanging out at an abandoned mining site

By the time we were headed back to town it was almost 5pm, so we stopped at a brew pub in Ouray for dinner, then headed back to the campsite to do it again the next day.

Day 4

Nate and Christi hike the road at Cayton Campground

On Saturday, Christi was tired of sitting in the car for three days, so I took Anna and Gabe and we headed back to Telluride for day 2 of the LCDC.

Quite likely the largest gathering of 200-series Land Cruisers in the US

Lazerturbo91 and m1911 atop Imogene Pass at 13,114′

We met up in the parking lot and found a small group to do Imogene Pass and at least one person willing to do Black Bear Pass with us.

Drone shot from the top of Imogene Pass

Water crossing on Imogene

Most people (us included) travel Imogene from Telluride to Ouray (west to east), ascending the mining road up and over the mountain and then descending into the forest.  It was a beautiful trip and aside from dragging the spare tire in a few spots the cruiser handled it with aplomb.

Shelf road on Imogene PAss (it’s narrower than it looks)

Flexin’ the suspension on Imogene

A huge thanks to Jeff from Baltimore (lazerturbo91 on ih8mud) who followed me on Imogene and Black Bear and took the photos of my truck – all the photos from day 2 shown here are courtesy of him.  Thanks to CodyAustin as well, both for leading us up and over Imogene safely as well as for setting up this year’s LCDC.

“You don’t have to be crazy to drive this road – but it helps!”

To get back to Telluride we had two options.  Cody and his family aired up and took the highway, but Jeff and I decided to brave the shorter but more treacherous Black Bear Pass.  Black bear is known for its shelf road, steep drops several hundred feet tall, and extremely tight off-camber switchbacks.  About once a year someone misjudges a ledge and rolls off; the week before we arrived someone rolled their FJ Cruiser (thankfully nobody was hurt).  This would be not only my first time on Black Bear, but also my first time as a trail lead.

Sheep crossing

Just as we got to the start of the trail around 12:30pm the rain started.  We decided to brave the summit and hope the weather would clear.  The trip up was straight-forward dirt and rocks with rain on and off.

Steeper, rockier part of the ascent

Our trucks handled the trail fine, though more than once I found myself scraping the spare tire or front bumper and radioed Jeff to take a different line than I had run.  Although his plastic bumpers took a few hits his mostly stock truck did quite well.

Summit

We reached the summit just after 1pm and stretched our legs before the descent.  The rain had temporarily stopped, but the wind had picked up and the clouds were rolling in quickly.

At the summit

The initial descent went quick though the narrow shelf road was harrowing.  We reached the most difficult part known as “the steps” and got out to walk the trail to see what we were up against.  I would be going first, and with limited visibility inside the truck I asked Anna to spot me and Jeff to assist her.

Narrow ledge at the start of the steps. Maybe a spotter would be a good idea…

The trail was steep, off camber, with a jagged rock wall on the passenger side ready to dig into the body panels and a steep drop off on the driver’s side.  As Anna and Jeff started directing me down the steepest part, the rain and hail started.

Jeff descending the steps

The truck slipped on the wet rock in a few spots, sliding forward more than I had intended.  Thankfully the two of them pointed me through the hardest parts quickly, and the rain slowed as we finished the first turn.

Jeff on the first switchback. Telluride is in the distance

Jeff walked back to his truck and I got out to spot him on the way down next.  The rain picked up, and his descent was even more slippery and harrowing than mine.

Parked after the switchbacks

Jeff finished his descent and the rain stopped just in time for him to break out his drone for a few shots before a group of four other trucks came down behind us a few minutes later.

Another group behind us

Don’t let your guard down after the steps- the switchbacks are still steep and narrow

We hopped back in our trucks and headed down the mountain and the remaining switchbacks.  Although the first few required a 7 point turn, none of them seemed as scary as that first switchback on the steps.  The remaining shelf road was a relative breeze, and we were treated to a spectacular view of Bridal Veil Falls from the road below.

Anna spots me on a switchback

Downtown Telluride, CO

We headed into town and met the rest of the LCDC crew for a BBQ dinner in downtown Telluride, anxious to share our stories of battle over a few local pints.  I’d absolutely do Black Bear Pass again, but next time I’m going to watch the weather report and try to avoid doing it in the rain and hail.

 

Days 5, 6, and 7

Petroglyph Hike

Sunday we packed up early and headed to Mesa Verde National Park, camping a few miles away at Target Tree Campground.

Cliff Palace, Mesa Verde

Pro Tip: For anyone planning to camp there, be warned that the GPS coordinates on the NPS website are off by about 30 miles.  The correct location in N37°20’26”, W108°11’16”. We stopped at Mesa Verde along the way and followed a rocky ~2.4 mile hike to a wall of petroglyphs, returning via the flatter mesa, then continued on to the campground. 

Don’t look down!

The following morning we returned to Mesa Verde to visit the Cliff Palace and Balcony House cliff dwellings, hiking down into the canyon and ascending via several wooden ladders up to 32′ tall.  It was amazing to think these structures had been around for almost a millennium.

The following day we hopped in the truck and drove west to Canyons of the Ancients and Hovenweep National Monuments.

Canyons of the Ancients

We started with a few hikes, the rocky terrain reminding us Moab, and the took the (lengthy) clockwise route around Canyons of the Ancients National Monument to Hovenweep National Monument.

Disbursed campsite along Cutthroat Trail

Afterwards we went looking for a building called “Painted Hand”.

Panoramic view of Hovenweep

 

 

 

 

We never did find it, though we did take a fun 4WD trail that was moderately challenging we later found out was called “Cutthroat”. Tired we returned to our campsite, ready to pack up for New Mexico the following morning.

Day 8

We packed up with the artist town of Taos, NM as our next destination.  Once again we left early, this time taking an unplanned diversion to the Grand Sand Dunes National Park.

Great Sand Dunes

Although we initially decided to stop by to tick it off our list of national parks, we found the park incredibly beautiful with rivers, mountains, and far more to do than initially anticipated.

Fawn Lakes Campground

We were disappointed that we could only spend a few hours and determined that we would have to come back another summer when we could dedicate several days. Back on the road, we finished our drive to Fawn Lakes Campground near Taos and Red River, NM, arriving just in time to pitch camp and head into town for dinner.

Day 9

Taos Pueblo

We started off the day at Taos Pueblo, still occupied and permitting visitors.  

The kids (including us big kids) snacked on fried bread, looked at Pueblo jewelry and art, and then wandered the Pueblo checking out the buildings, culture, and talking to the native americans.

We then headed to the Black Rock Hot Springs for a lazy dip.  Unfortunately several people who seemed to have lost their clothes had beaten us there.  Never discouraged, we headed further up river and took a trail down to the beach where the kids played in the water until they were ready for dinner.

Days 10 and 11

Downtown Santa Fe

Once again we packed up camp, and drove just a few hours to Black Canyon Campground in the mountains to the east of Santa Fe.

We set up camp, finishing up as a big storm approached, and then headed into town for a few hours.  Our plan was to check out some of the shops and museums, but unfortunately the power was out through most of the downtown area, so we ended up just wandering around until dinner.

Cave dwellings at Bandelier National Monument

Yes it’s as steep and high as it looks.

The following morning we headed to Bandelier National Monument, just outside Los Alamos to the north.  The cave dwellings weren’t as intricate as those at Mesa Verde, but it was very cool to climb up the ladders and into them.  One set at the end of the trail had several steep wooden ladders, including one that was over 40′ tall.

In the afternoon we drove southeast to Pecos National Monument.

Church remains

The red clay brick was dramatic against the blue sky, but the unique thing about this monument is that you can actually climb ladders down into the kivas.

Kiva at Pecos

After running around for the day we made our way back to the campground to cook dinner and relax, knowing we had quite a long drive ahead of us tomorrow to get to Carlsbad Caverns.

Day 12

We would visit Carlsbad Caverns that evening, and then leave the following morning for Big Bend.

Roswell that ends well

The Guadalupe Mountains

A few weeks before leaving my friend Dave Johnson told me about his trip out west though and insisted that I had to visit Guadalupe National Park.  I had planned 4 full days in Big Bend, plus three days to return home, and as our trip went on we had debated trimming one day to check them out, knowing we were unlikely to come back.  So we rearranged our trip and decided to camp an hour south of Carlsbad at Guadalupe NP for the night, just across the Texas border.  We would visit Carlsbad the next day, and then leave the following morning for Big Bend.

A stream along a hike at the base of the mountains

We arrived at the park around 4pm, and were disappointed to find out that the wooded campground was only for tent campers.

Those with trailers, RVs, and vans could only camp in the parking spaces designated for RVs at the start of the trailhead.  By this point however we were tired from the drive and didn’t want to backtrack 90 minutes to our original campground, so we paid the $8 and set up for the night.

We broke out the hibachi and grilled chicken for tacos in the parking lot, ate dinner, and played cards in the camper.

Once the sun set, the parking lot went dark and we were treated to an absolutely amazing view of the milky way.

Day 13

The following morning we wanted to do a hike before heading up to Carlsbad Caverns.  El Capitan sounded epic, but would have taken a full day.  The ranger recommended a hike called The Devil’s Hall, meandering from the trail head up a dry river bed.

Steps to Devil’s Hall

The Devil’s Hall

The round trip hike took about 3 hours, most of which thankfully was at least partially shaded.  The walk back to the camper was faster than the hike down (isn’t that always the case).  We got back to the camper, ate lunch, and started the trip back into New Mexico to see Carlsbad Caverns.

We’ve been to a few natural caves before such as Luray Caverns, VA and Mammoth Cave, KY, but Carlsbad Caverns, with its enormous great room was even more impressive.  Equally memorable was the smell of bat droppings that littered the entrance to the cave and permeated the air.

Steep walk down into the cavern. Thankfully there’s an elevator to take you back up.

Entrance into Carlsbad Caverns

The steep walk into the cave took about a half hour, the first part reeking of bat guano.  We held our noses and braved the smell, descending about 750′ underground.

We were treated to the typical stalactites and stalagmites, of course, but also a interesting history of the caves.

Original ladder

For instance, when the early explorers visited the caves, they used wooden rope ladders to descend and had only candle-lit lanterns.

“Bottomless pit” (it’s actually 184′ deep)

We finished off the tour of the great room, including the infamous “bottomless pit”.  From our vantage point the bottom was just black, so it’s no surprise early explorers thought it went on forever.  We learned from the sign however that modern explorers have descended it and measured a depth of 184′ – not quite bottomless, but I wouldn’t want to climb down.

Day 14

Christi in front of El Capitan

Departing Guadalupe the following morning we headed to Big Bend National Park, our last big site.  We passed El Capitan at the southern end of the Guadalupe Mountains and drove south to Marfa before entering the park through Terlingua, TX.

Prada “store” near Marfa, TX

For the uninitiated, Marfa is an artist town in west Texas.  Apparently some artist built a replicate of a Prada store in the middle of nowhere, filled with shoes and purses just like a real store.  (The front door, however is inoperable.  It was funny enough to we had to stop and take some photos (along with three other cars passing through the area).

Cottonwood Campground

We continued on to Big Bend, stopping at the visitor’s center for information on the first-come, first-served campsites available in the park.

We’re melting!

Being mid-August and 102F, the rangers suggested we use the Rio Grande Village RV site, the only campground in the park with electricity.  Stubbornly I decided we weren’t going to stay in another parking lot, and after checking out the Chisos Basin (which wasn’t really designed for trailers), we set up at Cottonwood Campground.  The campground was completely empty.  That was a plus as the kids were antsy and so the noise wouldn’t bother any neighbors, but it foreshadowed what was to be the hottest night any of us had ever experienced.  That night we killed the battery, draining it until the meter had a frown.  It never fully recovered.

Canoeing the Rio Grande

Day 15

The following morning we packed up and headed into Terlingua.  We met our river guides at Big Bend River Tours, and they drove us into the park for a lazy day of canoeing and swimming in the Rio Grande.

Fun fact: the US-Mexico border actually runs through the center of the river.  However, you don’t need a passport unless you set foot on land on the Mexico side.  If you are caught crossing into (or back from) Mexico by the US border patrol, Customs and Immigration levies heavy fines and possible jail time, so we did not wade across and touch the Mexican side, we didn’t stop our canoes on the Mexican shore to stretch our legs, and we certainly didn’t climb on their muddy banks and jump into the Rio Grande over and over in an effort to cool off from the sweltering 100+F heat.

Terlingua church

That evening after a brief rest, we headed back to Terlingua, parked the camper at an RV park, cranked up the A/C, and ate dinner at the Starlight theater.

Terlingua jail

Terlingua is a ghost town that has been partially re-established.  Originally created to support the local quicksilver (mercury) mine, the town shut down in the 50s but now supports a small population. Apparently Terlingua is home to the original chili cookoff – and it showed.  The burgers were good but the Terlingua chili was outstanding.

Day 16

We went back to Terlingua for breakfast and locked Nate up in the town jail (just for a moment).  We wandered through the town, checking out a few old buildings (some barely standing), rusty vehicles, and a church which appeared to still be in use.  Then we headed out to do some hiking and 4WD exploration in Big Bend National Park.  

First stop in the park for the day was Santa Elena Canyon.

Santa Elena Canyon, Big Bend

We had originally hoped to raft the Rio Grande through Santa Elena Canyon, but we had been told earlier in the week that the river level was so low that the outfitter wouldn’t be able to float a raft.  Thus the day before we ended up in two canoes along a less dramatic (but still beautiful) section of the river.

We still wanted to see the canyon, so we drove south to the river and the took a 1.2 mile hike out to an overlook inside the canyon.  The view of Big Bend was incredible, but the temperatures were already soaring and so afterwards we decided to explore a more remote area of the park by taking the 4WD-only River Road, which winds along the basin near the Rio Grande for about 60 miles.

River Road

The higher parts of the River Road are gravel and are passable by any normal clearance sedan.  However the bluffs regularly wind down to a dry river bed with ruts and moguls.  Most would have been passable in 2WD, but high ground clearance was definitely required.

Mariscal Mine

We followed the road for a few hours, pausing to take the occasional photo.  Lacking shade, we stopped for lunch at ate off the back of the truck.

Trail into the unmaintained Black Gap

About 3 hours in we took a short detour and stopped at the Mariscal mine, an abandoned mercury mine.  Storms were rolling in from the distance, and as we didn’t want to get caught crossing a low lying river bed during a storm, we took a few photos and headed back on the trail.

Bottom of Black Gap

The next section of trail was called Black Gap, and featured a narrow passageway and moderately steep section with a drop of about 2′ at the end.  While I was concerned at first having read that the park service no longer maintains the trail, the steep section had cement mixed in with some of the rocks (presumably to keep it from deteriorating) and some prior visitors had stacked rocks at the bottom to ease the drop.  It was fun, but after our adventures in Colorado we were surprised at how easy it was.

As the rain picked up we sped up the pace and hit pavement about 45 minutes later, the whole trail having taken 4 to 5 hours.

Day 17

Chisos Basin

We originally debated leaving Saturday, but after experiencing the August heat in the Chihuahuan desert and facing a 24 hour drive home we decided to spend the morning hiking and then head out after lunch on Friday instead of leaving early Saturday morning.

The Window

We headed up into Chisos Basin, leaving the trailer at the visitor’s center (the park service does not recommend trailers longer than 20′ on the road leading into the basin).  The hike was about 4 miles round trip, leading us to a narrow but amazing view of the park.
We ate lunch, hooked up the trailer, and hit the road for home.  Our plan was to stop somewhere in Oklahoma for the night, then in the Mark Twain National Forest the following evening just to break up the long trip back.

Day 18

Coasting on fumes? Nah we had at least 6/10ths of a gallon left in our 24.5 gallon tank.

We drove through a few tremendous downpours in Texas before stopping for BBQ in Abilene.  After a harrowing nighttime drive through multiple towns with no gas station, we found fuel and were able to fill up, before ultimately stopping to rest at an RV park just shy of Wichita Falls.  (I wasn’t too worried, we had 4 gallons in our rotopax on the roof, just in case).

Mark Twain National Forest

The following morning we hit the highway early and pressed on to the Mark Twain National Forest.  We arrived in the late afternoon, found a free campsite, and set up for the evening.

Day 19

The final day of the drive home was uneventful.  It was dinner time by the time we arrived home, so we unhooked and unpacked, thrilled to take a warm shower longer than 60 seconds, turn on the TV, and start on a pile of dirty laundry that rivaled any of the mountains in Colorado.

Fun road trip stats:

  • $1943.83 in gas
  • ~5300 miles (I accidentally reset the trip meter, but this is pretty close)
  • 8.1 MPG unadjusted (about 8.5 MPG after compensating for tire diameter)
  • 36.6 MPH (unadjusted)
  • 144.8 hours in the truck (aka “Butt-In-Seat” time calculated as miles / MPH)

Side note: I think my mileage hit this year was a combination of reduced aerodynamics from the new front bumper and a trailer that is almost 1000 pounds heavier.

Next Year

We’re still deciding what to do next year.  Maybe Rocky Mountain NP -> Great Sand Dunes -> Durango, CO -> Moab?  Maybe Glacier and BANFF?  Maybe Acadia?