Snowpocalypse and RV WiFi

I was more than a little surprised that Apple consider "snowpocalypse" to be a real enough word that it didn't try and autocorrect to something else. I guess if it's on Wikipedia it must be a real word. There have been predictions of doom and gloom going around Alaska from the Bering Sea into the interior. Blizzard conditions. The snow is easy to deal with but if it gets really windy, a lot of the shallow rooted trees may topple and take out power lines (and Internet cable!). The plastic straight edge on the deck rail, in the cat tree view, is about 16" long and they are predicting another 8" or so for this afternoon and evening. The plow on the truck made pretty quick work of our driveway but I kind of wish that I had put tire chains on yesterday. The subdivision road hasn't been plowed yet but we are probably pretty far down the list.

As you can see in this map from the Alaska Dispatch, Fairbanks is really on the edge of the storm. It hasn't really snowed much around here since this morning. Some places near the Bering Sea got really hit pretty hard with freezing rain on top of snow. This combined with strong winds. So far, we haven't seen the strong winds that everyone was afraid of around here.

7:15pm: The NWS is reporting that the "main event" will show up tonight by 8pm.

8:02pm: Now revised to 9pm.

1:40am: 25 mph winds. No snow on the trees anymore. Hopefully the wind will die down soon...

5:30am: Still some occasional gusts.

Lots of power outages overnight. 

Wi-Fi Repeater

So what do you do when sitting inside on a snowy day. I chose to revisit the configuration of the Ubiquity devices that I had picked up from Amazon a few months ago. These devices will be used to extend campground or other "free Wifi" into the RV. The "Router" configuration option was missing from the NanoStation LocoM2. I downloaded and installed the newest v6.0 firmware and the missing option is now magically available. I configured the NanoStation as a router (not SohoRouter which was there before) and I could now select the wireless side as the WAN interface which is what faces the Internet. I then started the DHCP server service which supplies IP addresses to the wired side. The "2" in the name refers to the frequency that the radio operates. I.e. 2.4 GHz only so it is 8.2.11B/G only. But that is sort of the lowest common denominator as far as open WiFi.

From the antenna sensitivity plot off of the Ubiquity website, you can see that the antenna is nominally directional so the front just needs to be roughly aimed towards the base station antenna. A common mounting point is on the fold down TV antenna that most RVs seem to have. When the previous owner replaced the roof, he didn't bother reinstalling the antenna since it was for the old analog frequencies. Since the folding antenna also rotates, it would've been a convenient place to install the NanoStation. Maybe I'll attach it to the rear roof ladder with some sort of easy way to rotate it. Or maybe just reinstall the base and fold down mechanism of the old TV antenna.

The next piece to be setup is the wireless bridge, the Ubiquity AirGateway. I had never even heard of this option until Dom mentioned it. There is also a model with an small antenna attached for more range for your internal WiFi. This device snaps onto the NanoStation PoE (Power over Ethernet) power supply and is essentially a tiny WiFi router. On the picture, it is attached to the power supply and makes up the right third with the Ethernet cables attached. Before I had set up the AirGateway as a router and the NanoStation could only be set up as a bridge which, to me, was not optimal. The AirGateway is now set up as a bridge and the IP address of both devices are on the same subnet. The NanoStation will be placed on the roof of the RV somewhere with an outdoor rated Ethernet cable run into the rig to the AirGateway. When inside the RV, your devices (phones, tablets, laptops, etc.) would always be configured to access the SSID of the AirGateway and not the campground WiFi.

Upon arrival at a campground, you connect to the NanoStation management interface and select the "Wireless" tab. Click on the "Select" button and a window will open showing all of the 2.4 GHz networks that it can see along with the signal level. If the campground has multiple access points, you just select the one with the most signal.

If there is a WiFi password, you enter it in in the Wireless Security portion of the same page. You then click the Change button which is the same as save/commit/restart. The NanoStation will then restart and should be ready to go in about a minute or so. This is not as plug-and-play as some of the commercial products such as a Wifi Ranger which have a lot of additional features but this is about ⅛ the cost. I'll deal with the additional hassle. Plus, I have a lot of experience with Ubiquity products from the Barrow project. Also note that this is for WiFi only and not cellular data. Different equipment would be needed to boost cellular data. I haven't decided whether I need access to cellular data

RV - Solar and DC Upgrade (Part 1)

A winter storm is forecasted to be hitting interior Alaska tomorrow. I'm hoping that we don't have any major problems. But in the meantime, this post has been keeping me busy for the last couple of weeks. Another 100% non-moto related post but I've been learning a lot. If we lose power during the upcoming winter storm, I may be getting some use out of the RV stuff to run the home heating system (oil fired boiler).

I have decided to install some solar panels on our fifth wheel RV. This post is sort of a continuation from my other posts on the comparison of PWM and MPPT charge controllers and 12 VDC Systems. And I'm not sure how many parts there will be. This picture was taken from the rear of the roof looking towards the front. There is a lot of room up there. The front vent pipe, circled in red, runs through the basement storage right behind the rear wall of the front battery compartment and through the bathroom wall next to the shower. The height of the interior wall is maybe about 6 1/2' and is the shortest run from the roof to the front battery compartment and the logical place to run the cables. The panels will probably be put in front and on each side of the front air vent (Circled in yellow). Unfortunately, I didn't measure the space or even take a picture of the area so I'm not exactly sure of the dimensions.

I have been reading a lot about solar power installations and it is a real mix of information. Some good and solid others a mix of hearsay and personal opinions. But I guess that's pretty much the definition of the Internet.  This post is a description of the solar system that I will be installing. Much of the stuff has been purchased already. Other items will need to wait until the rig is actually sitting in front of me but a detailed design needs to be done before a single screw is installed. That is the purpose of this post.

Some definitions:

• I_sc - Short circuit current i.e. maximum output under standard conditions
• I_mp - Current at the maximum power point
• I_solar - Charge controller input current
• V_mp - Voltage at the maximum power point
• PWM - Pulse Width Modulation
• MPPT - Maximum Power Point Tracking
• DC - Direct Current (what you would find in your car)
• AC - Alternating Current (what you would find in your home)
• Inverter - Converts DC to AC
• Converter - Converts AC to DC (glorified battery charger)

It may seem odd to start with the inverter but it determines the size of the battery bank as well as the size of many of the bits and pieces of the system such as wire, fuses and switches. Not to mention how much solar you need to keep the batteries charged. Most of the product links are to the device on Amazon.

Inverter: Xantrex PROwatt 2000 true sine wave inverter. Rated at 1800 watts continuous. Maximum current I_max= 1800 watts / 10.5 VDC = 171 amps. 10.5 VDC is the minimum voltage before the inverter sounds an alarm and shuts down. Add in a 25% safety factor and you get 214 amps. Based on this, the catastrophic fuse, DC cutoff switch and the battery/inverter cables will be rated for at least 214 amps for a short period of time. The Xantrex recommends a 250 amp class T fuse and 2/0 or 4/0 awg for distances of up to 6'. Since my cable runs from the battery bank to the inverter will be significantly less, I will be using 2/0 wire. The ampacity of the 2/0 Cu wire is 283 amps and the voltage drop from the battery to the inverter would be 0.07 VDC.  I will be using a 250 amp class T as the catastrophic fuse for the whole DC system and the inverter is, by far, the biggest potential consumer of power.

Solar Charge Controller: After a lot of research, I picked up a Morningstar TS-45 PWM solar charge controller. Being a PWM controller, the input and output current will be the sum of I_sc of the 12V solar panels. The TS-45 is rated for 45 amps and the input and output DC circuit breakers are rated at 50 amps. A benefit of the circuit breakers is that they can be used like a switches to isolate the charge controller. And the output needs to be connected to the battery before the panels are connected. The TS-45 has a temperature probe to adjust charge rate based on the temperature of the battery bank and a battery voltage sense wires to compensate for any resistive losses in the battery cables. Morningstar has been around for a number of years and this was strongly recommended for smaller installations.

I was initially leaning towards the 30 amp Bogart Engineering PWM controller since it could tie into a Trimetric 2030 monitor to configure all sorts of parameters. I ended up getting the Trimetric 2025 monitor after deciding not to get the Bogart solar controller. But was still trying to decide between PWM and MPPT. MPPT is slightly more efficient and PWM is cheaper. Since this is a small solar installation, the efficiency gain from MPPT isn't really enough to matter. The Morningstar TS-45 was about the same price as the Bogart controller, has more growth potential (45 amps vs 30) and does offer not only an optional remote monitor but also has both an RS-232 connector and an EIA-485 connection. By adding the network option, you can even monitor and control through a web interface. For some reason, I find that option attractive. Several web sites mention that while a remote monitor may be cool to look at it really isn't needed. The Trimetric gives you much more useful information. By the way, everyone seems to recommend installing a Trimetric monitor even if you never go beyond that. The most useful mode is percentage of battery capacity left. Kind of like a gas gauge.

Solar panels: Renogy 100 watt, 12V monocrystalline panels. I_sc= 5.75 amps, V_mp = 18.9 VDC. The TS-45 could handle at 7 or 8 of these panels so I_solar = 5.75 amps x 7 = 40.25 amps. I do not plan to install this many panels at this time. But I like having the option. Maybe 4 for now but there is room for growth. The I_solar value will be used to size the cables from the combiner box on the roof down to the charge controller in the front compartment. You might notice that the rated output of the panel is 18.9 VDC x 5.29 amps (I_mp) = 100 watts. With the PWM charge controller, the actual output of the panel into the battery will be lower as the current will remain the same but the voltage will be lower.

Battery bank: 4x6V golf cart batteries from Sam's Club. 215 amp-hours each yielding a battery bank of 430 amp-hours @ 12VDC. This photo is from LoveYourRV.com but I was able to find the same battery box locally. And these are Interstate batteries. Sam's Club carries Duracell and Energizer golf cart batteries which some dismiss due to their much lower cost. They are all flooded lead acid with about the amp-hour rating. The "gold standard" are Trojan T-105 and Crown batteries at more than double the price. I picked this photo since Ray is also using 2/0 arc welding cables for linking his batteries and the same size battery box. Each pair of batteries are wired together in series (i.e. negative to positive) so the voltage is added. Two 6VDC batteries in series equal 12 VDC. Then the two pairs are wired in parallel (i.e. positive to positive, negative to negative). This combination can be treated as a single 12 VDC battery with a rating of the amp-hours of each pair added together. In this case 430 amp-hours using the 20 hour discharge rate.

There is just enough room in the front compartment for adding another pair of batteries but that would add another 130 lbs. The batteries are mounted in a box which is vented to the outside through a hole in the bottom and a hose in the lid. Since the non-sealed batteries produce flammable gas, you would not normally locate any electronics in the same compartment. The vented box eliminates the risk. Plus, there are so many openings in the compartment for the landing jacks and slide hydraulic lines, there is plenty of fresh air.

250 amp fuse
w/o housing

Battery/Inverter Cables: The inverter will be running at maximum output for very short periods of time. This inverter would run down the 440 amp-hour battery bank pretty quickly. 2/0 arc welding cable will be used for the battery interconnect cables as well as the battery cables. It has a free air rating of 283 amps (not in conduit).

50 amp circuit breaker

Solar Panel to combiner box: Two panels wired in parallel on each cable. 11.5 amps @18.9 VDC - 10 awg. MC4 solar specific connectors.

Combiner box to TS-45: Up to 45 amps @ 18.9 VDC - 4 awg. In my install, 23 amps @ 18.9 VDC going through a 50 amp circuit breaker located near the TS-45 controller.

TS-45 to catastrophic fuse: 2 awg through a 50 amp circuit breaker.

Combiner Box using Home Depot
Parts

Combiner Box: This is a waterproof plastic junction box mounted on the roof where the 10 awg solar panel cables are tied together to a single feed from the roof to the charge controller. Using the voltage drop calculator on Calculator.net with 12 VDC and 45 amps, the voltage drop using 4 awg cable from the roof to the charge controller will be 0.17 VDC or 1.42% for a 7.5' one way run. The target is under 2%. The photo is a combiner box using one made from PVC boxes and fittings from Home Depot or Lowes. This is from the Mobile Homesteading Solar Services website. One of several great resources.

The inverter will be used to supply 110 VAC to the outlets including the microwave. It will not be used to run the air conditioner, the water heater and (obviously) the converter. Kitchen appliances such as the microwave and coffee maker will probably be the largest consumers of 110 VAC but their use will be limited. Primarily the AC power will be to charge devices, Bridget's CPAP machine, TV and network. All pretty low power consumers. There are several ways to provide the inverter AC into the RV. Inline, a transfer switch and dedicated outlets. I ordered a Xantrex 15 amp transfer switch which can be wired into one circuit of the existing electrical panel. Since I don't know how the 110 VAC panel is wired, I may or may not end up using that method. Ray from LoveYourRV.com wired his 1000 watt inverter to two dedicated outlets. One near the TV and the other in the bedroom. Anything plugged into those outlets will alway be running off of the inverter.

If the automatic transfer switch won't work with the panel layout, then I'm going to take the inline approach. I will be running from the inverter to a 20 amp breaker in the pass through storage area ending in a 30 amp RV outlet that I can simply plug the RV power cord into. I will manually switch off the circuits on the main breaker panel that should never run off of the inverter. (A/C, water heater, converter) There is a switch on the refrigerator which can be used to force it to run off of propane. If AC is available, that would normally be the default.

Other 12 VDC devices are the lights, furnace blower, refrigerator controls (and light), hot water heater controls, CO detector, water pump, slide hydraulic pump and controls, landing jacks (on the front) and the stereo. Of these the lights and furnace are the large consumers due to the length of time that they may be running. I will be changing out most of the lights with LEDs but I didn't make an inventory of bulb types when I was there.

The next post will have a schematic and the initial assembly onto a 5/8" piece of plywood that will eventually simply be screwed into the front compartment. I can have it completely pre-wired. This is a long post that I started while recuperating in the hotel room in Seattle.

Just a few of the many resources used in no particular order:
http://www.jackdanmayer.com/rv_electrical_and_solar.htm
https://wyominggypsysmobilehomesteading.wordpress.com/
http://www.calculator.net/voltage-drop-calculator.html
https://handybobsolar.wordpress.com/
http://www.loveyourrv.com/
https://www.altestore.com/blog/
https://www.solar-electric.com/
https://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity
http://amsolar.com/
https://www.renogy.com/

Merry Christmas!

Merry Christmas from our family to yours!

Last year we were in Los Angeles on Christmas Day. This year, we should be back home on the 25th. On Friday, we went on short stroll looking for some "Christmassy" things to put into this post. The hotel had some nice decorations up in the lobby. Lots of nice displays in store windows especially as you approached the big retail area surrounding Pike Street Market. There was even a few flakes coming down much to the chagrin of some of the locals.

Wandering Around Seattle

The winter solstice was another walk-filled day. We started out this morning by looking for the surgery center that I need to be at bright and early tomorrow morning. After breakfast at Ihop we walked down to the Pike Place Market again and explored the many passages and levels before getting overwhelmed with the sheer number of people. We headed for the Seattle Aquarium and the Seattle Great Wheel a short walk south. The aquarium at $25 each and the ferris wheel at $13 seemed high. Or maybe I'm just a cheapskate. We searched for and found a couple of geocaches in the area before stopping at Ivar's Acres of Clams for some hot tea and snack. Plus, it was a chance to warm up. Seattle feels cold and damp.

On the short walk from Pike Place Market, we passed this building which I thought looked kind of interesting. Not sure why, maybe all of the straight lines. No idea what the building is/was used for, it just happened to be on the way. With all the walking, I'm always looking for an excuse to stop and pretend to do something important before charging up the next hill.

I needed to pick up some paperwork at the clinic before they closed so it was another steep, uphill hike. The hills here seem as steep as those in San Francisco. According to the Pedometer++ app on the iPhone, 32 floors and 6.5 miles. Just for comparison, the workout app on the Apple Watch, which are both completely different and unassociated, says 6.46 miles. That seems pretty consistent to me. Both Pedometer++ and the Apple Watch workout app used the phone GPS for their initial calibration. After that initial calibration, they both just use the accelerometers (one in the iPhone and the other in the watch) to conserve battery power.

Thursday Afternoon - Feeling a little queasy from the pain meds but otherwise doing fine. We are scheduled to head back on Christmas Day. 

Not In Fairbanks

Back to the non-moto content...

Monday evening - This is the view from rooftop terrace on the hotel. We are in Seattle for a bit for medical reasons that I'd rather not elaborate on. I'll just be glad when it's all done. We are staying near Virginia Mason and today, after my initial appointment with the surgeon, we did quite a bit of walking. We finally ended up at Trader Joe's for some non-perishable breakfast food. (No free breakfast at the hotel)

This is a little closer to the amount of walking that I used to get pre-retirement. Today, it felt like a lot. Maybe it was the 29 floors of uphill that I'm feeling. There's noone to blame for slacking off on the walking except me. It's not like I don't have time...

Tuesday Evening - This morning, we walked down to Pike's Market for a little bit of sightseeing but it was pretty crowded probably due to the Christmas season. We met up with some friends from Fairbanks, who happened to also be in Seattle for medical reasons, for coffee. At Tully's not Starbucks. We then headed to Pacific Place for lunch and I needed a place to sit still for a couple hours for an audio conference. I think I found the only bench in the mall.

After my audio conference, we walked up the hill to the Starbucks Tasting Room on the corner of Pike and Minor. It was crowded, loud and it didn't smell like they were roasting any coffee at that time. I must admit to not being too impressed with the place. So after looking around for a bit, we then headed back to the hotel for some rest. These hills give you quite a workout. My Pedometer+ app claimed 21 floors so far today but only 3.6 miles so far.

PBC #3

Here is the third Polar Bear Challenge video that I need to "qualify" as a participant. I'm still on campus in a small dirt lot between student housing and married student housing in the beginning. A nice open space to do some donuts (not on the video). I then headed from campus out onto University Ave and Farmers Loop Rd.

Shortly after this video was made, we got another 8" of snow. It took me over half an hour to get the plow hooked back onto the truck. Probably more time and effort that it would've been to just use the snow blower to clear the driveway. There was enough snow built up on the driveway that the truck and the plow no longer lined up. Maybe I need to find somewhere else to store the plow...

Anyway, here is the third PBC video.

PBC #2

The second video for the Polar Bear Challenge. If you are interested in some of the other submitted videos, they can be found at http://polarbearchallenge.tk/. The mild inversion can really be seen in the temperature. At the house, it was +12°F and at the university, it was +6°F. A difference that you can really feel.

I opted for a liesurely ride around the university due to the extremely slick roads and no studded tires. The roads are always really slick when it warms up after being really cold. I think that the road surface is still really cold and it gets a layer of frost.

Anyway, here is video number two.

PBC #1

Surprise, actually a post with a little bit of moto content.

I didn't plan on submitting any videos to the Polar Bear Challenge this year but today was nice and warm and I had found the GoPro charging cable. It took only a few minutes to attach the monopod to the cargo rack and run the cables to the USB port in the sidecar. I had to search for the remote but eventually had it attached to the windshield strut. The Polar Bear Challenge only requires three video submissions, only one video per day, that has at least three minutes of riding with a starting temperature of 32°F or lower. Pretty minimal requirements.

Here is the first video.

RV - Solar Charge Controllers

Another long, non-moto post. This, as well as the previous post, are written to help me solidify my thoughts on RV mods. Still too cold for riding (-20°F for most of the week).

My justification to installing solar panels is convenience not dollars. If there is a reasonable amount of sunshine hitting the panels each day, the battery bank will be full every afternoon without running a generator. Less noise, less hassle. Plus, since the RV is considered a second home, I heard that there is a 30% tax credit available until 2019. Then starts decreasing until 2021 where it stays at 10%. I got my information off of the AMSolar.com site.

I have been doing a lot of reading on RV solar installations and one of the first sites that I found with really useful information was LoveYourRv.com which is the source of this photo. Ray, the author of the site, has posted a lot of information and reviews including a number of YouTube videos documenting his modifications including the installation of solar power. One of the continuing debates on the solar front seems to be around the two dominant charge controller technologies. Ray defers to other articles such as this one on the Bogart Engineering website which explains why PWM controllers are more cost effective for smaller installations. There has been a lot written about both.

http://e-bluelight.com/

PWM, or Pulse Width Modulation, takes the input current from the solar panel and varies the duty cycle when sending it to the battery. This is shown in the figure on the right. This is an overly simplistic description of how they work. Most of the decent charge controllers provide up to four charging profiles. Bulk, Absorption, Float and Equalization. The last one, equalization, only applicable to flooded batteries. Most PWM controllers are fairly sophisticated and will modify their charge rate based on the type of battery, current charge level and battery temperature so your batteries won't get ruined from overcharging. The panels you select must be designed for the battery voltage you are planning on using. For example, a 100 watt panel for a 12 volt batteries have a operating voltage of around 18 volts. Since the panels are rated at their operating voltage, the peak current for this panel would be 100 watts/18 volts = 5.56 amps. Since the PWM controller just rapidly switches the current on/off based on the charge state of the battery, the current is limited to 5.56 amps.

http://www.leisurebatteriesireland.com/

MPPT, or Maximum Point Power Tracking, takes the full input power from the solar panel (P_max) and as the output voltage decreases, the current is proportionally increased resulting in almost as much power output to the battery. This is an oversimplification as well. Most MPPT controllers also track battery temperature, battery voltage and panel output voltage. They continuously correct and compensate using a variety of algorithms to stay at P_max. There is a lot of Internet discussion about the efficiencies of these algorithms but the differences are more applicable to much larger solar installations than you would find on an RV. Except for conversion inefficiencies, the full power of the panel will be sent to the battery. In other words the charge controller will adjust the output current to always deliver almost the full power of the panel to the battery.

Example:
PWM: If the battery was deeply discharged, say down to 11.8 VDC, the power going into the battery could be as low as 11.8 V if the battery was still being discharged at a rate greater than the solar charge rate. Using a 100 watt panel rated at 18V
11.8V x  5.56 amps = 66 watts
As the battery charges, the voltage and watts going into the battery increases. But even at 14.4V the current is still at its maximum value of 5.56 amps.
14.4V x 5.56 amps = 80 watts

MPPT: Same situation with an MPPT charge controller. As you can see, as the output voltage decreases, the available current increases. Power-In = Power-Out.
5.56amps x 18v/11.8V = 8.5 amps
8.5 amps * 11.8V = 100 watts
5.56 amp x 18V/14V = 7.15 amps
7.15 amps x 14V = 100 watts

The MPPT controllers cost more. And there isn't a whole lot of difference in real world performance, especially with a modest system. The efficiency drops as the voltage difference between input and output increases plus there is always a conversion inefficiency. Heat would be a byproduct of that inefficiency. Also, the higher the solar panel temperature the lower the output voltage and the smaller the difference in power output between the two controller technologies. So in the example above, output power would be 90 watts assuming a 10% loss in the conversion, In reality, while the batteries are being charged, they would more likely be in the 13V - 14V range so the difference between the two technologies is in the 10% range. On a multi kilowatt system, 10% is significant. On a 400 watt RV mounted system, less so...

This is one of the charge controllers that I'm considering. It is the Renogy 40 Amp Commander MPPT Solar Charge Controller (CMD40) which is rated at 40 amps. On a 12V system, it will handle up to 520 watts of panels. It has an optional remote monitor, the MT-50, that is required for any advanced configuration. If you really want to dig into things, there is an optional USB cable with Windows software that could be used instead of the MT-50. Battery temperature uses an optional probe that you attach to a battery terminal. There were some negative reviews on Amazon but they were from people that didn't realize that you need a specific remote monitor. They bought the cheapest on Amazon which wasn't compatible with this particular controller. The CMD40 has a maximum input of 150 VDC so I am not limited to 12V panels (V_mp = 18V) or having to run the panels in parallel. A decision on which panels has not been made. The conversion efficiency of this controller is claimed to be 96% using 400 watts of 12V panels and drops to 95.5% using 400 watts with 24V panels. I like the flexibility.

The other charge controller being considered is the Morningstar Tristar TS-45 shown here with the optional display. It is a 45 amp PWM charge controller that has been around for a while and has a lot of fabulous reviews. It uses an external battery temperature probe on the battery bank for temperature compensation. It has an optional remote display to show current from the panel and voltage but the remote isn't needed for configuration like the Renogy Commander. There is a RS232 port for custom configuration. Just using the dip switches, you can choose battery profiles and there is one for flooded, lead acid with absorption voltage of 14.8V. This controller will support 800 watts of panels and you are limited to 12V panels only. Battery equalization can be done manually or automatically. Manual equalization is important due to the higher voltages needed at lower temperatures. For example, at 0°C the equalization voltage is over 16V. This is over the limit of the inverter even when powered off. In fact, all of the DC loads should be disconnected during equalization. Since I have the Trimetric 2025, I really don't need a separate charge control monitor.

Under optimal conditions, 4x400 watt panels, 450 amp-hr battery bank discharged 50%. The approximate time to fully recharge the battery bank would be 8 to 10 hrs. The "real life" charge time would be about 20% longer since the battery bank will be flooded lead acid batteries which, according to what I've been reading, needs about 20% more power put in over what was used. 

RV - New 12 VDC System

Sorry. This post sort of got out of hand. Very long. I guess that's the result of cold temperatures. Not much else to do.

It started out with the combination lock purchase back on "Black Friday" but I really couldn't pass up on 40% off. That sort of got the ball rolling. High on the "list" was a larger battery bank and an inverter to provide AC power even when not plugged into shore power like you would be in an RV park. I decided on two pairs of 6 volt golf cart batteries with each pair wired in series and the two pairs wired in parallel. Steve, the owner of the shop where the trailer is being stored this winter, sent me the dimensions of the front bay where the existing deep cycle battery is located. The only thing on the rear wall of the compartment are a couple of circuit breakers for the 12 volt system.

I found a covered plastic battery box at a local solar shop here in Fairbanks that is designed to hold the four golf cart batteries. It is ½" smaller than the short dimension of this space so it should fit perfectly. I need to add a vent to the lid to fit the hose from the existing battery box. The golf cart batteries are lead acid wet cells so hydrogen gas is generated during charging needs to be exhausted out of the compartment. There is a hole in the bottom of the compartment that will need to connect to the bottom of the new battery box. The capacity of the 4 golf cart batteries is 450 amp hours of which about half is useable on a regular basis. The local Sam's Club has Duracell GC-2 golf cart batteries at a significant savings over the well regarded Trojan T-105. The specs are similar but according to the Internet, they may not tolerate really deep discharges as well. But for half the price...

I will be installing a piece of plywood on the back of the compartment to simplify the installation of the other pieces of the 12 volt system. The existing 12 VDC circuit breakers will be moved onto the board. I ordered a 2000 watt pure sine wave inverter (1800 watt continuous, 3000 watt peak) to provide AC power from the batteries. This is enough to power most things in the RV including the microwave and a Keurig coffee pot.  It won't run the air conditioner and it'll be foolish to run the water heater which can run on propane. The parasitic draw of this inverter is 0.800 amps so I will be installing a remote power switch. I'm still debating whether to install a transfer switch and a subpanel breaking out just the circuits that I want powered off of the inverter. These would include the just the kitchen, bedroom and living room outlets. It may be convenient to run the refrigerator (324 watts peak) off the inverter while on the road instead of propane. To determine the actual power consumption I'll need to use my Kill-A-Watt meter to measure actual watt-hours during normal usage. On some of the solar forums, some people have measured their RV refrigerators to use about 3 kw-hrs per day. This would be about 250 amp-hours from the battery bank over a 24 hour period. This is reasonable but your mileage may vary.  Two other alternatives for power distribution are to run a couple of strategically placed dedicated inverter outlets or just plugging the shore power cable into the inverter after switching off unwanted circuits at the breaker panel. I'm thinking that automatic may be the way to go.

The peak current draw of the inverter is about 250 amps @ 12 VDC according to the Xantrex web site. This requires some fairly large wiring. I found a table on the Internet that lists the ampacity of different gauge wire and 1/0 AWG wire is rated at 170 amps @ 90°C. By locating the inverter near the battery bank the voltage drop at peak current would be a very reasonable 0.1 volt based on a cable length of 5' with a resistance of 0.09827 mΩ/foot.

I have about 10' of 2 awg arc welding cable that a fellow Airhead gave me back when I was installing the Cozy sidecar onto the BMW. Welding cable is preferred since it has a lot of fine strands and is very flexible. Since the inverter will be the largest consumer of power, I will probably use 2/0 wire for all of the the battery cables. The inverter and the remote switch was ordered from Amazon. I didn't think that Amazon would honor the free Prime shipping but I was wrong. It arrived yesterday.

This afternoon, I tried out the crimp tool for heavy gauge wire. This wire was on the 2 awg and it was a good test. The crimp tool is designed for use with a hammer but since the hydraulic press was handy, I figured why not. It resulted in a very solid mechanical connection. No solder needed.

I've been reading a lot articles and watched several YouTube videos on RV battery systems and solar power. And all of them recommended the installation of a battery monitoring system before doing anything else. Another black friday sale purchase was the Bogart Engineering Trimetric TM-2025-RV along with the required shunt and cable. I ordered them from Northern Arizona Wind and Sun and they shipped via USPS. (If you ship to/from Alaska, USPS is the cheapest option especially the flat rate boxes) The shunt is rated at 500 amps and is to be mounted on the negative battery cable and measures all current in and out of the battery bank. The shunt has a very low resistance and the Trimetric measures the voltage drop across the shunt and calculates the current. This is the older model which does not have the ability to control the Bogart Engineering PWM solar charge controller.

I haven't decided on solar but if I did install solar panels, I am inclined to go with a MPPT charge controller instead of a PWM model due to the increased efficiency. In this diagram from teslaxcanadadotcom.files.wordpress.com, at low battery voltage, the actual charge rate for a PWM controller is a fraction of the panel rating. Where the MPPT controller will always charge at the maximum wattage the panel produces. I'll go into more detail in another post if I actually decide to install solar power. Amazon won't ship solar panels to Alaska so I have plenty of time to do more research. In fact, the local solar shop has a small selection of panels with the price around $1/watt. Their panels are designed for residential use (higher voltage = less resistive loss) and require a MPPT charge controller to be used on a 12 VDC system. I will do another post on solar once I've decided not just what but if.

I also plan on ordering a two 2000 watt gasoline generators that can be hooked up in parallel. Both will be needed to run the roof air conditioner but only one for most other things. So the solar is not essential but it sure is a lot quieter than running a generator to charge up the battery bank. The generators will be stored in a toolbox in the bed of the truck along with their fuel supply. One larger generator may be more convenient but I like the idea of having a "spare".

Over the holidays, I plan to set the battery system up in the garage by mounting these and other components to the plywood board including the Trimetric monitor and making all of the cables. This will allow me to test the components and simplify the installation into the RV in the Spring. Other components include ground bus, 12 VDC switch for the inverter and a 250 amp catastrophic fuse for the positive side. Should be interesting.

As a side note, has anyone else noticed this type of traffic? I think it's odd but interesting...

Blogger "Comments"

I don't know about others but I have been regularly getting generic "comments" left on blog posts. Not obvious spam but the text of the comment is so generic that it doesn't relate to the contents of the post and the name is a link to a commercial site. Following the instructions on this site, I edited the Blogger template to disallow links in the comments. This disables the backlink that these commenters were looking for supposedly to improve their Google ranking. The following was added right before the end of the body block.

Our weather hasn't really changed much and wasn't really conducive to doing anything outside. Even the heated garage was hovering around 40°F so no bike work was done beyond digging out the battery tenders. I did need to reinstall the plow since we've gotten about 8" of snow since we've been back from PA.

There was a great turnout on Monday evening for our last Airhead meeting at the Silver Gulch. I believe that 20 people showed up. Several harassed me since I didn't ride out.

So Much Negativity

I don't see much to be positive about in this screenshot from this morning. Welcome to Fairbanks. We still don't have much snow yet. Actual snow depth on the ground may be 5" - 6" or so. We could really use a bit more to avoid frozen sewer and water pipes. It looks like it's going to be cold for a while.

We just arrived back home last night from our quick trip to PA. Since we wanted to arrive home before midnight, we had to return through Los Angeles. This made for more time in the air (more airline miles!). Maybe it'll be enough to bump me up to the next tier in Alaska Airlines loyalty program.

I stopped at College Coffeehouse this morning and was greeted with "Where's the bike?". It may be in the garage for a while as it probably won't be warm enough to ride (maybe +10°F) for a couple of months. Time to dig into some of those maintenance items...

RV Farkle?

Another zero moto content post. Is it still a farkle if it isn't installed on a motorcycle? It's kinda shiny. I took advantage of a Black Friday online sale (40% off!) to pick up this door lock for the RV. Even though I won't be installing anything until Spring, I figured that I may as well start collecting things that I wanted to install or change out. I've heard a lot of reviews of this door lock and being able to open the door without a key is more than simply convenient. Especially since we will be traveling with pets. Trying to break in to the RV after getting locked out would be stressful. It also includes physical keys and a small wireless remote.

I spent part of the long flight on Thanksgiving Day making a prioritized list of RV changes and additions. So far, priorities 1-5 have been defined ranging from "need" to "nice to have". Some of the accessories in the "need" category are things that I used on previous RVs but no longer have. I had just included them when we sold the last travel trailer as most of the items were getting kind of old. Priority 1 items are things that I have defined as safety related or essential. Things like water and sewer hoses, battery monitor, TPMS, bedding (mice got into the mattress), voltage and water pressure regulators and a second propane tank. Priority 2 items are things that I think we need to make a long trip less stressful. Examples of these items are deep cycle golf cart batteries, generators, a better converter, a large-ish inverter, LED lighting, Wi-Fi repeater and a backup camera. Generators is plural as two 2KW generators are easier to handle (lighter) and can be run in parallel if we need to run the A/C. Not to mention that sometimes it's nice having a "spare". Most of these priority 1 and 2 items will be aquired/installed before our trip this summer and some of them have already been picked up.

I spent a lot of time looking into installing solar panels to minimize generator usage and it is a priority 2 or 3 depending on the charge controller selected. The solar is also in the "interesting" category as it's something new to me. I still might try and install some solar before or trip this summer but maybe only do 200 watts instead of the planned 400. I originally had a cell phone booster as a priority 3 but dropped it to 4 since I don't "need" access to the Internet. The Wi-Fi repeater was left at priority 2 since it is relatively cheap.

 

Bridget and I are currently in PA on a quick trip to visit her dad. We left on the red-eye on Thanksgiving morning and arrived in Baltimore at 4:30 pm. Lots of time sitting in one place. But I still managed to get my activity circles closed (see previous post). And Thanksgiving dinner was at a Cracker Barrel. Here at the assisted living home the Christmas decorations are starting to line up. They are getting ready for the next major holiday.

BTW, this post was written using BlogTouchPro on the iPhone so pictures aren't "clickable". 

Obsessed?

I really didn't feel like going out today. I must be getting soft in my old age. But I had at least one errand to do this morning. I needed to pick up something a little more comfortable than jeans for an airplane ride towards the right coast. Especially since my "minor surgery" last week is still making it somewhat painful to sit for any length of time and needing to occasionally take pain medication. I think that it may be a long plane ride.

Since I was heading into town, I stopped at College Coffeehouse and there were a couple of the regulars there. That's really when I realized what the temperature was. It made the coffee that much better. After coffee, I headed over to REI and picked up a pair of fleece pants. Very comfy and I was finally able to use up my dividend.

I tend to get caught up in things that may not mean much. An example of that are the exercise "rings" on my Apple Watch. Based on your activity during the day these rings gradually complete. The center ring is just from standing up for a few minutes every hour. The next ring is from some sort of activity such as walks and the outside ring is just estimated calorie consumption from everyday activity. Last month, I decided to at least try and "close the rings" every day. It seemed like a modest goal. Some would say that I am obsessed since the watch will remind you to stand up every hour.

The "rewards" are these little virtual badges that show up on the phone. So does this make me obsessed?

Road Grimed Astronaut

Look what showed up in the mail today from Aerostitch. Earlier in the week I got an email from Andy Goldfine (or more likely from a staff member) asking me how the Roadcrafter Light was working out. This was prompted by a couple of photos that Dom posted on his blog from the Garden of the Gods Park a few weeks back. I gave them some feedback and mentioned that it has been used almost daily over the last 2 1/2 years in temperatures ranging from -47°F to +107°F (-44°C to +42°C). There was a signed thank you note in the envelope along with the two patches and sticker.

One comment that I made was that when this riding suit eventually gets replaced, it will be with a Roadcrafter Classic instead of the Light. But that wouldn't be for quite a while. I am in the process of repairing the little pockets that hold the magnets in the collar. The material is actually worn through in a couple of areas like this.