Transitioning to LiFePO batteries

LiFePO4 Battery on shelf, during installation

 

After doing my most recent research, I decided to replace the faltering AGM coach batteries with a LiFePO4 battery.  The decision was the easy part. Next came selecting a battery, installing it and integrating it into the existing Roadtrek 12VDC system.  I also have a solar system and de-sulfating controller.  Such a controller is not recommended with the LiFePO4.

The battery can be mounted in any position, and the space available provided two options.  I decided to go with terminals up. I did elevate the battery slightly by resting it on plywood.  It has a metal case and I don't want it sitting in water.  I've never had an issue with water in the battery pan but I don't ford streams or drive through flooded underpasses. There is always a first time.

The new battery will use the existing shunt and power wiring in the compartment.  The integration of other components did require some additional work on my part. I didn't want to make alterations to the existing wiring of the coach: no shortening or removal.  I wanted the wiring to be recognizable to a technician familiar with the Roadtrek or a future owner.  I also wanted to provide the ability to transition back to AGM batteries at some future time, although I don't expect to do that.

Maintenance Free LiFePO4 batteries?

There are limitations with any coach battery and LiFePO4 batteries have their own.  I decided to address these in my installation. 

It is true the LiFePO4 batteries are "maintenance free".  One significant advantage over other battery types is the internal, electronic battery management system (BMS) which is there to protect the battery.  (See Note 1).

However, to achieve optimal battery life (4000+ cycles) it must be operated within the design parameters.  That may require some external hardware.  I concluded that in my Roadtrek, replacing AGM batteries with LiFePO4 is not quite "plug and play" or "drop in and forget". 

Integrating the various 12VDC Components - a List

The LiFePO4 batteries aren't simply a "drop in" proposition. Here are the things I considered:

1. Tripp-Lite charger/inverter is to remain in place.
2. Retain Tripp-Lite 750W inverter function (~59A at 12.8V).
3. Make the provision for a future LiFePO4 charger. 
4. Solar charging system - update to compatible LiFePO4 controller.
5. Upgrade the battery manual disconnect.
6. Retain existing volt-ammeter and shunt.
7. Add a low voltage automatic disconnect to enhance the BMS cutoff (to preserve the battery).
8. Add battery compartment supplemental AC/DC heat to extend charging time.

Low Temperature Battery Considerations

One of the issues with the LiFePO4 batteries is their intolerance to cold.  The BMS will not allow charging if it determines that the battery internal temperature is at 32F or below.  Power output will vary with ambient temperature, but not as much as with the AGMs I'm replacing.   

High ambient temperature may accelerate the aging of the battery while low temperature may reduce output power capability. In general LiFePO4 batteries perform better at low temperatures than do the AGMs I'm replacing. 

I decided to install the battery in the unheated compartment where the AGM batteries were installed.  Minimal 12VDC power wiring changes would be required.  In that location the battery will be exposed to freezing temperatures at any time the outside ambient is below freezing.  Of course, I do have the option of relocating it to the interior of the coach at some time in the future.

Keep in mind that if stored outdoors all Class B's will have their interior temperature decrease to below 32F in fall and winter if the vehicle is north the freeze line. In cold weather the coach interior will be at cold until it is warmed by running the engine.  So too will any batteries stored within.  If the coach is parked in the sun the interior may be warmer than outside. The Roadtrek coach battery can be discharged when cold, but the LiFePO4 battery can't be charged until the battery internal temperature rises above 32F.

I concluded that to store the Roadtrek in winter, if that is necessary below freezing conditions that I'll simply remove the batteries.  If I use it at below freezing temperatures some supplemental heat to warm the batteries would be desireable. That will extend the charging of the LiFePO4 battery as weather cools.  

I do realize that at some point the ambient temperature will be so low as to nullify the supplemental heat and the BMS will prevent charging the battery. I don't expect to encounter that situation. LOL.

Some batteries are available with internal 12V heaters but that draws down the battery in cold weather if the vehicle is not running and not connected to shore power.  Furthermore, if this is an internal battery function and can't be controlled by the user it simply runs the battery down faster if off the grid.  In my opinion that's undesirable in a RV.

I'll be installing both 120VAC and 12VDC supplemental heaters, which I can control.  I'll be monitoring the compartment temperature to get some data about the effectiveness. 

Avoid Over Charging and Over-discharging

Another issue is the possibility the internal battery cells can be damaged if they're discharged below a certain threshold. That low point is approximately 5 percent of total capacity. If the cells are discharged below this threshold their capacity can be permanently reduced.  The BMS will protect the battery, but at too low a threshold to preserve optimum life. 

The solution is an external, automatic cutoff or a low voltage alarm (or both).  

I have installed a low-voltage automatic cutoff. 

Three methods of Charging

I have three methods for charging the batteries in my Roadtrek. Ideally, each method would provide the appropriate charging voltage and current for LiFePO4 batteries, but they don't:

1. Tripp-Lite charger inverter using 120VAC power (3-stage voltage and current control).
2. Solar using solar panels and a controller (voltage and current control).   
3. Engine alternator (simple voltage regulation, no control).

The first two methods can be adjusted to adhere to the battery charging specifications.  The alternator has no such adjustments.  To avoid over-charging the coach batteries I can use the battery separator to disconnect from the alternator and rely upon solar charging.  Alternately, a DC-to-DC charging system could be installed.  There are practical limits to how much I'm willing to spend on this.

External low voltage disconnect - Details

The battery manufacturer recommends that an external low voltage disconnect be used.  The manufacturer suggests 11.2V as the disconnect point.  

• Battery low voltage disconnect < 11.2V

Such a voltage represents about 5% battery capacity remaining.

There are a couple of methods to achieve this:

1. Manual switch.
2. Automatic switch or relay.

It is true that the battery management system will protect the battery from complete discharge. However, 10.4V is about 2% battery capacity.

• BMS Low-Voltage disconnect <10.4V

In general, a battery constructed of Grade A cells can probably achieve the specified cycles if the battery is operated within the manufacturer's parameters.  Discharge to very low voltage is to be avoided. 

A battery low voltage alarm is a possibility, too.  For example:

• Battery low voltage alarm < 11.8V

Such an alarm would occur when the battery capacity has decreased to about 8%. 

Adjusting to a new reality.  As I use the LiFePO4 battery I'll have to adjust.  For one thing, the output voltage versus State of Charge is different than the AGMs.  The new battery is more stable than the AGMs.  After charging, and intermittent use for a week, the battery voltage has decreased by 0.06V.  This battery seems to be much "stiffer" than the AGMs.  This may change as the battery ages and capacity decreases to about 80%. 

State of Charge - SoC - Details

I provide a typical chart later in this post.  State of Charge (SoC) is a very useful battery measurement. It states the present, actual capacity of the battery compared to its total capacity. 

State of Charge is a percentage: 

• 100% SoC means the battery is fully charged, new and undamaged.
•  0% means fully discharged. 

 SoC is calculated this way: 

• State of charge (%) = Remaining Capacity (Ah) / Total Capacity (Ah).

LiFePO4 batteries are chemical devices and so they operate similarly to the AGM lead acid batteries we are familiar with. There are several SoC values to keep in mind.  These are the absolute minimum SoC, the preferred SoC and the actual SoC.  

Absolute minimum SoC is the most discharged state with the lowest possible terminal voltage that doesn't destroy the battery.  For my battery this is 10.4V.  However, discharging to such a low voltage will diminish the capacity and useful cycles of the battery. 

For maximum battery life, only discharge it down to the Preferred level, but no lower. Hmmm, that seems reminiscent of the recommendations for AGM lead-acid batteries, doesn't it?  Here are the three values:

• Alarm and recharge at <11.8V (the Preferred minimum state of charge, 8-10%). To maintain reasonable battery longevity and performance do not discharge below this value.
• External battery cutoff <11.2V (Actual minimum state of charge, 5%). This is the realistic minimum.  The battery can be discharged to this state, but some battery degradation and performance will occur is the battery is operated this way.  This discharge level is a trade-off between available power and battery life.
• Battery BMS low voltage cutoff <10.4V (Absolute minimum state of charge, 0%). This is approaching the point of battery destruction.  The BMS will stop battery discharge when this state is reached. 

LiFePO4 Terminal Voltage and SoC

A typical 12V LiFePO4 battery is constructed of four cells called a 4S battery pack. The battery output voltage decreases as the batteries discharge and remaining capacity decreases.  A typical 12.8V battery output will vary from 13.8V to as low as 10.0V (completely discharged).  

The nominal output voltage is 12.8V.  There are differences among manufacturers, but here are typical voltages:

• Absorption Voltage (charging) 14.4-14.6V  (3.6-3.65V per cell).
• Float (fully charged) 13.6-13.8V (3.4-3.45V per cell).
• Full discharge 10.0V (2.50V per cell).
• Nominal voltage 12.8V (3V per cell)

The terminal voltage will decrease as the battery discharges and the capacity diminishes.  To get an accurate reading of SoC the battery must be rested.   Here's a typical chart. You will note that the battery output voltage is reasonably flat throughout the useable discharge cycle, from about 100% down to 10%:

• 13.6 V = 100% SoC (Fully charged)
• 12.1V  = 10% SoC (Preferred minimum)
• 1.5 V output decrease from Fully charged to minimum SoC.

LiFePO4 Capacity versus Battery Voltage 

Note:

1. There are different battery constructions out there.  Some have as many as 8 internal cells. This is an evolving and improving technology. Low temperature automatic protection by the BMS and internal 12V heaters are relatively new.  Some batteries are well constructed internally, and some are not. Some have steel cases, while most have plastic. Prices range from about $325 to $900 for a 12V, 100Ah battery.

(c) N Retzke 2022

Lithium-Ion Battery Update - I changed from AGMs

 

100 Ah LiFePO4 Battery

During the FMCA Rally, I had an opportunity to attend a battery seminar and also discuss features and current prices with several battery vendors.   In February 2015 I posted here about Lithium-Ion LiFePO4 batteries. In that post I said: "a similarly rated lithium battery system will probably deliver about 45% more power than a similarly rated AGM battery system, and it will probably do so for at least 6-7 years."  

Here's a link to the earlier post:

Are Lithium RV Coach Batteries Expensive?

In August 2017 I posted this comparison:

Comparing AGM and Lithium RV Battery Systems

In March 2018 I posted this:

Lithium Battery and RV DC Power System Developments

In October 2019 I posted an update:

Coach Batteries - AGM versus Lithium-Ion Update

The battery seminar was cancelled. I'd been hoping to get current information and insights. I discussed with FMCA and advised them that I could provide a 1-hour presentation.  For one thing, I have nothing to sell and I'm very familiar with what's available, the costs, as well as the pros and cons of each battery type. However, there were several battery vendors at the rally, and I had the opportunity to talk to Battle-Born, RVConnection, etc.

One of the Roadtrekkers brought up coach batteries in a conversation and told me he was interested in building a LiFePO4 battery.  That piqued my interest.  After the rally I did some additional research.  

My AGMs were installed in January 2017.  They are 5-years old.  I do test the capacity of my batteries from time to time and I had determined it was about time to replace, as the capacity has diminished, which is normal. BTW, using the Roadtrek LED indicator isn't very useful for this.  I measure the battery voltage under load and monitor the decrease in voltage over time under load.  By discharging the battery at a constant current, I can observe the decrease in battery voltage.  That's how I know the battery condition.  I admit it is a rough estimate, but adequate for my needs.  

Some Roadtrekkers use the LED L-F-G-C volt indicators.  I don't. The "G" indicator is illuminated at about 11.9V and above.  My AGM batteries are at 25% SOC at 11.9V OC (Open circuit), which is below the minimum 50% state of charge necessary to achieve rated life. 

Is it time to change to Lithium?

I had once again been thinking about switching from AGM coach batteries to Lithium-Ion.  I too was interested in building my own batteries.  I decided to check prices, which have changed significantly in the past couple of years.

What I discovered was I can purchase a complete battery for about the same price as building one.  In one of those oddities, the price of the components is now nearly equal to the price of some of the assembled batteries; I guess the marketing people in the factories in China figured it out. A year or so ago the parts were less costly than the batteries, but no longer. This is not surprising because a 12V LiFePo4 battery requires these components:

• (4) 3.2V LiFePO4 Cells.
• (1) Battery Management System (BMS).
• Screws, buss-bars, wire and terminators for the BMS.
• (1) Case, which is sometimes called a Rack, to hold the cells.

Add up the cost of all of the above and compare to the cost of some of the batteries available. At present there isn't much of a difference.  I won't put the component numbers here. However, I decided that while assembling my own battery would me a fun exercise, there was no financial incentive for me to do so.

Note: There are some very low-cost Lithium LiFePO4 batteries available. I've seen prices as low as $300 for a 12V 100Ah battery. However, the price range is from $300 to $900.  I decided to do research into testimonials and specific battery reviews as part of the selection process. I also decided to make a simple specification so I could do a reasonable comparison. 

Be aware that there are different grades of 3.2V LiFePO4 cells; A, B, C, etc. Those cells are assembled in a case with a battery management system (BMS) to make a 12V, 24V or 48V battery.  Grade A cells are more expensive than Grade B cells. Grade B cells are characterized as "unqualified" at manufacture.  Maximum benefit is achieved from a LiFePO4 battery constructed from Class A cells.  But different manufacturers use different standards.  So, a Class A cell from one manufacturer may be the equivalent of a Class B from another.  Confusing, isn't it?  That's why it is a good idea to purchase a battery from a known manufacturer (or assembler) who provides a proper warranty. 

Battery Prices and available capacity:

One thing that is unchanged is the price differential of AGM batteries versus LiFePO4. True, the lowest priced lithium batteries are competitive with AGMs, but may not offer features or warranties. Determining battery quality isn't easy. I decided to avoid the lowest cost lithium because there are different quality levels in the cells.

Bottom line is, the AGMs are less costly, out-of-pocket.  However, if one compares the capacity of the batteries and charge-discharge cycles, the LiFePO4 offer superior performance. 

Furthermore, because we seldom boondock, I don't need a lot of Ampere-hours from the batteries.

Here's an "out of pocket" price comparison.  I priced an inexpensive 12V AGM battery as follows:

• AGM (lead acid) = $219 + shipping + tax
• LiFePO4 = $569 + shipping + tax

There is a capacity difference and that should be considered.  Considering how I use my Roadtrek, the fact that I do have solar available, and I have an Onan generator, I really don't need two 100 Ah Lithium batteries. However, a single 110Ah AGM could only provide 55Ah which is not sufficient. As a consequence, I need to compare 220Ah AGM to 100Ah lithium.  This would be adequate based on available capacity:

• (1) 220Ah AGM = 110 Ah available (50% maximum discharge)
• (1) 100 Ah LiFePO4 = 80 Ah available (80% maximum discharge)

Battery price per Watt-hour (Wh):

The following is a simple cost comparison and doesn't consider lifespan, number of cycles or battery performance degradation. In fact, it would be more accurate to use 50% capacity for the AGM and 80% for the LiFePO4.  Discharging below those levels can ruin the AGM and may reduce the lifespan of the lithium battery.

For example, one 12V, 100 Amper-hour (Ah) assembled LiFePO4 battery which has acceptable specifications has a price of $569 plus shipping plus tax. That's $0.44 per Watt-hour (Wh), as follows:

$0.44 = $569 / (12.8V x 100 Ah)

A 12V, 100 Ampere-hour (Ah) AGM battery has a minimum price of $219.  That's $0.18 per Watt-hour (Wh):

1 battery $0.18 = $219 / (12.5V x 100 Ah)

2 batteries = $0.36 per watt-hour

If I were to purchase a single 206 Ah LiFePO4 battery, the cost per Wh would be less, while the price of two AGMs would be twice the capacity for twice the price:

$0.39   = $1,029 / (12.8V x 206 Ah)

Prices above are "raw" which is to say, a simple cost per Wh.  However, if we consider the life of the batteries, the numbers change.  An AGM battery can provide 500 charge-discharge cycles. A Lithium-Ion battery can provide 4,000 charge discharge cycles. The LiFePO4 battery can be repeatedly discharged 80% and the AGM 50% to provide this cycle lifespan.

Realistic battery price per Watt-hour (Wh):

In fact, the AGM battery I would be inclined to purchase would be the Deka 8AGC2.  This is a 220Ah  6 V battery which closely matches the original furnished with the Roadtrek. Two would be required to get 12V, but at 50% useable capacity they would provide 110Ah at 12.5V. The cost each is $300 + shipping + tax. This is the realistic AGM battery cost per Watt-hour:

AGM batteries: $0.44 = $600 / (12.5V x 110 Ah)

One 12V, 100 Amper-hour (Ah) assembled LiFePO4 battery which has acceptable specifications has a price of $569 plus shipping plus tax. It has a 80% useable capacity, 80Ah. That's $0.56 per Watt-hour (Wh), as follows:

100Ah Lithium: $0.56 = $569 / (12.8V x 80 Ah)

The AGMs when new can provide energy at a lower cost than the Lithium.  However, the Lithium batteries will provide more power over their lifetime because they can tolerate greater number of charge-discharge cycles.

Comparing Charge-Discharge Cycles

If we consider charge-discharge cycles, then these batteries can provide these Wh over their lifespan:

Lithium:   3,840 KWh = 4000 cycles x 1200 Wh x 0.8

AGM:      300 KWh = 500 cycles x 1200 Wh x 0.5

As can be seen above, the lithium can provide 12.8 times greater power (3840 / 300) over its lifespan.  Considering battery lifespan, the lithium batteries are substantially less costly.

Cost over the life of the batteries

If I take the initial cost and divide by the number of useful years, I can arrive at an estimated cost to own per year.  I am using my experience with my AGM batteries, which provided 5-years of useful life in my Roadtrek. For comparison I'm using the warranty period of the LiFePO4 batteries. Note that the warranty is 7 years but can be extended to 10 years.  To make this comparison, I'm using two AGM's (100 Ah useful) and one LiFePO4 (80Ah useful).  I'm ignoring shipping and tax, and I am assuming that the existing Tripp-lite charger/inverter will work with both batteries. That's the configuration I'm considering.

Lowest cost AGM:  $88 per year = (2 x $219) / 5 years

Deka AGM: $120 per year = (2 x $300) / 5 years

LiFePO4: = $82 per year = $569 / 7 years

If one can get a 10-year warranty for the LiFePO4 batteries, the cost per year is further reduced, and the Lithium battery is less costly than the AGM:

LiFePO4: = $57 per year = $569/10 years

Advantages and disadvantages

Lithium LiFePO4 batteries have these characteristics:

1. Can be repeatedly discharged to 80% with no reduction in battery life. In other words, a 100 Ah battery (1200 Wh) can provide about 960 Wh safely without decreasing battery life. A similar AGM battery should not be discharged more than about 50% repeatedly.  The AGM can provide about 600 Wh, which is 63% of the power provided by the LiFePo4 battery.
2. The Lithium can be charged-discharged about 4,000 to 8,000 times, or cycles.  The AGM battery, if discharged repeatedly to 50% can be charged-discharged about 500 times, or cycles. The lithium can be charged-discharged at least 8 times more cycles than the AGM.
3. The Lithium battery provides power at 13.2VDC.  This may gradually decrease to 13.1V when discharged to 40% capacity.  At 20% remaining the battery will be about 12.9V.   The AGM begins at about 12.9V and decreases to about 12.3V at 50% state of charge.  At 20% remaining the battery voltage will be about 11.7V.  Actual output may vary by manufacturer.
4. The Lithium cannot be charged at temperatures below 32F (0C).  To do so the battery will be ruined.  Using Lithium batteries in below-freezing conditions takes some forethought.  However, they can be discharged at any temperature. Adding a battery heater can solve this problem.
5. The LiFePO4 battery may be mounted in any position (but check with specific manufacturers for their limitations and recommendations).

My Specifications  & Tripp-Lite Charger-Inverter Settings

To make an apples-to-apples comparison of LiFePO4 batteries from various suppliers I had a simple specification:

1. Minimum 4,000 cycle life.
2. Internal Battery Management Systems (BMS).
3. Low temperature cut-off to protect the batteries.
4. Over charge & over discharge protection
5. Over current & short circuit protection.
6. High temperature disconnect.
7. Storage as low as -22F. Discharge temperature range -22°F to 140°F.
8. Charging temperature range 32°F to 140°F.
9. Charging Current range 0 to 20A (maximum 50A).
10. Maximum output 100A.
11. Be compatible with my Tripp-lite charger (14.4V Charging Voltage and 13.5V float, maximum 45A charging current). - Note 1, 2, 3 below.
12. A minimum 7-year warranty.
13. Prefer a removeable cover and replaceable BMS, but not mandatory.
14. Blue-tooth (r) communications optional.

Note 1: The Tripp-lite has two charging settings for two different types of batteries:

• "Wet Cell (vented)" (DIP Switch A1 in the DOWN position) and
•  "Gel Cell (sealed)" or AGM (DIP Switch A1 in the UP position).  

Note 2: The Tripp-lite has three stages for charging: BULK, ABSORPTION and FLOAT.  The "Absorption" and "Float" stage voltages are adjusted by selecting the battery type:

• Wet Cell: 14.4 VDC "Absorption", 13.5 V "Float".
• AGM: 14.1 VDC "Absorption", 13.6 V "Float". 

Tripp-lite BULK Stage: In this stage, the battery is brought up to about 80% capacity using a constant charge current; the charge voltage can vary in this stage.

Note 3: The Tripp-lite has two charging current rates:

1. 11 Amperes (DIP Switch B4 in the UP position).
2. 45 Amperes (DIP Switch B4 in the DOWN position).

Battery Selection & Sizing Considerations 

To choose LiFePO4 batteries it would require these decisions:

• Choose (1) or (2) 100Ah batteries (total 100Ah or 200Ah capacity; 80Ah or 160Ah useable).
• Or choose (1) 200Ah battery (160Ah useable).
• Determine mounting location: (1) or (2) 100Ah mounted outside or (1) large 200Ah battery mounted inside the coach (the 200Ah battery is too large for the Roadtrek battery tray). Inside mounting would add cost, as additional 6AWG wiring would be required.
• A single 100Ah battery could provide 20A for 300 minutes (about 240W for 5 hours).
• A 200Ah battery could provide 20A for 600 minutes (about 240W for 10 hours).
• The Tripp-lite inverter is rated 750W continuous.  Ignoring losses, the inverter input for 750W AC output would be about 60A at 12.8 VDC.  The battery should be capable of providing that current output.  The inverter can provide 150% output for a short period of time, so a battery capable of 100A output would support that. Of course, higher battery current decreases available battery time; 60A output could deplete the 100 Ah battery within 100 minutes.

To protect the battery, a low voltage cut-off device at 11.2V is recommended.  The BMS of the battery I am considering will cut-off at 10.4VDC. However, this very low cut-off voltage may reduce battery life.  An in-line fuse is also recommended.  I do have a digital voltmeter installed, so I can rely upon that at the lowest cost approach.  Keep in mind that battery voltage is an indicator of the battery capacity, but the battery must be at rest for this method do be accurate.  "At rest" means nothing drawing a load.  In my Roadtrek I can use the battery voltage as an indicator if 1) The chassis/coach battery separator is in the "off" state, 2) the battery disconnect is "off" and 3) the inverter is "off".  About 15 minutes after disconnecting the LiFePO4 batteries I'll consider the voltmeter reading to be indicative of the battery capacity.  

Because the LiFePO4 can't be charged below 32F, mounting inside the coach has an advantage. The interior coach temperatures can be maintained above 32F while the coach is in use. However, if the battery were in the outside compartment a heating pad could be attached to the battery to provide some supplemental heat in the winter, thereby keeping the battery or batteries above freezing. It would be my preference to mount outside to conserve interior space.   The heater will add cost. 

Notes: 

1. Certain RV organizations including FMCA and Escapees may offer price discounts to members for specific batteries.
2. Certain manufacturers offer batteries which have internal heaters and have blue-tooth (r) communications.  However, this is at greater cost.
3. The Roadtrek battery tray is outside of the coach.  Care must be taken to assure that the LiFePO4 batteries mounted within stay dry.
4. The charging requirements of the battery selected must be compared to the capability of the Tripp-lite charger/inverter to assure compatibility.  Otherwise, a new charger and inverter would be required.  
5. I decided to purchase a single 100AH SOK battery pictured at the beginning of this post.  If purchased directly from the U.S. supplier, the warranty is extended from 7 years to 10 years.  My cost for (1) battery was $624.93.  This included tax and shipping.
6. If I decide to add a thermostat and 12V heater to keep the battery warm, my out-of-pocket additional expense would be about $40 (fuse, pad, thermostat).  A second 120VAC 84W heating pad with internal 45F thermostat is about $39. Why two? Well, if I decide to winter camp on 120VAC, I can heat the battery using shore power or the generator.  Alternately, I can use the chassis alternator to heat the battery using 12VDC while the Roadtrek is in motion or I can use coach 12VDC to maintain the LiFePO4 above freezing.  I have not purchased any parts, but I do anticipate installing at least the 12V heater.
7. My Solar system will work with the LiFePO4 battery.
8. Low voltage disconnect at 11.2V is recommended for maximum battery life. If I want to add an automatic cut-off that would be at additional cost. I currently have a DC display with alarm. Here's the post link:  New Voltmeter-Ammeter-Wattmeter for AGM batteries  

(c) N. Retzke 2022

Karaoke at the Cantina March 26, 2022

 

Karaoke in the Cantina

Many thanks to the FMCA for extending the dates for the Karaoke at the Cantina, Pima County Fairgrounds. Quite a surprise when the 7pm stage show headliners showed up at the Cantina at about 9:30pm and did a couple of songs. 

(c) N. Retzke 2022

At The FMCA Rally - Batteries

 

Electric Vehicle

While at the FMCA Rally at the Pima County Fairgrounds I noticed this electric vehicle on display.  The batteries had been removed from the chassis and are sitting on the bed.  Of course, there are seminars about RV batteries and also vendors.  I found this old vehicle to be interesting.

Wooden crated lead-acid batteries

Close-up view of the batteries

Gould was the battery manufacturer.  At one time they produced electrical switchgear, automation products and all sorts of electrical distribution hardware.

(c) N. Retzke 2022

At the Rally - FMCA - Day 2

 

Central Park at the Pima County Fairgrounds

Central Park at night, after the concert

Day 2 was a blast.  Seminars, food, vendors and entertainment.

Southwest Surfers Concert

Walking back to the Roadtrek

Roadtrek Group, at night

(c) Norman Retzke 2022

At the Rally - FMCA

 

Norm at the Rally

It's March 23, the first day of the Rally. We are parked with the Roadtrekkers and they are a nice group of people. We attended our first "Meet and Greet" yesterday at the 4:00 Happy Hour.

Entry was about 10:00am yesterday and the drive was uneventful.  The FMCA people we met were all extremely pleasant and helpful. We got an escort to our space, then we went on a walking tour of the central area. 

Today we'll be attending several seminars in the morning, and then vendor's areas this afternoon.

Entry to the Fairgrounds

A part of the Roadtrek International Chapter Attendees area
 

Our 210P

(c) 2022 Norman Retzke

FMCA Rally - Tucson Arizona March 23-26

 

It is finally happening.  The event was originally scheduled for March 2020 but was postponed due to COVID-19 concerns.   Per RVTravel.com:

“FMCA hasn’t hosted a convention in Tucson since 1985, so this visit is long overdue,” said FMCA events director Doug Uhlenbrock. “We are hoping that the fairgrounds will accommodate our needs well enough to become part of our regular rotation.” "One key element of the event is an RV Expo. Major RV manufacturers and dealers bring their latest models for tours. RV-related accessories, components, services and other products of interest to travelers will be represented as well. When not shopping, attendees can take part in seminars by RV experts. Topics range from tire maintenance, technology and safe driving, to RV trips to Alaska, New Zealand/Australia and more. A variety of daytime and evening entertainment is offered. Multiple options are available for attending. Those with RVs are invited to stay on site to enjoy all the activities. The gate registration price for on-site stays is $245 (electric hookups are extra), which also grants RV owners who are not members of FMCA a one-year membership. For attendees who want to view only the RV displays and the supplier and component exhibits, admission is $10 per day or $25 for a family of three or more; children 12 and under are free with an accompanying adult. Individuals with an active military ID are admitted free as well. The day pass for Wednesday, March 23, will also be good for Thursday, March 24." 

For more information at the FMCA:  https://fmca.com/index.php/fmca-tucson-2022-learn-more.html

For the RVTravel article:  https://www.rvtravel.com/big-fmca-rally-coming-march.../

==

We intend to be there, with the Roadtrek International Chapter, FMCA