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Thread: LIFEPO4 Cheap

  1. #11
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    Quote Originally Posted by jkwilson View Post
    Those 3.2V cells should charge just fine on a standard charger for anyone contemplating this path.
    Actually everything I read said that while you can charge LIFEPO4 on a standard charger the float charge is bad for the batteries. Also to get them fully charged you need a higher voltage. So I replaced my converter and also put in a DC to DC charger that raises the voltage and regulates the charge coming from the truck.

    Also I put the four cells and the BMS in the factory battery box.
    2020 Reflection 150 240RL
    2020 F250 XLT 7.3L Godzilla
    Curt A20 hitch with turning point locked
    Westinghouse igen4500 LIFEPO4 280ah 3.2v cells

  2. #12
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    Quote Originally Posted by timkoenig View Post
    Yeah I am holding off on solar and big inverters. But I have been thinking about another 280 in parallel and a 3000 watt inverter so I could run an air conditioner for 3-4 hours during no generator hours.
    Yes, many do not realize that you do not have to do the whole project all at once.

    It is quite reasonable to start with the Lithium battery upgrade and Lithium Ready Converter and simply add additional batteries as time and your wallet allows. Similarly, you can add either Solar or an Inverter as the next enhancement to the system until you have a complete (and robust) system.
    David and Peggy
    2019 Ford F350 Lariat, 6.7L Diesel, Dually, Long Bed
    Running with 20k Reese Goosebox (Love It) and Ford Factory "Puck" system.
    Stopping with 8,000 lb Disc Brakes and Titan Hydraulic over Electric Brakes system.
    Powering all this fun with 1200 Watts of Solar, two Tesla, Model S, battery modules, 24 volt Victron Inverter.
    2018 Solitude 310 GK

  3. #13
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    Quote Originally Posted by jkwilson View Post
    Those 3.2V cells should charge just fine on a standard charger for anyone contemplating this path.
    The problem with using a standard Converter with Lithium batteries (LiFePo4) is that the converter uses the voltage from the battery to trigger charging. Unfortunately (or fortunately), the Lithium batteries operate at a higher voltage during the entire discharge cycle (voltage only drops when the battery is almost drained). This higher voltage causes the Converter to not properly charge the LiFePo4 battery and you only get a portion of the energy storage you should. With a Lithium Ready Converter you will get the proper voltages for your Lithium batteries and be able to store the maximum energy for later use.
    David and Peggy
    2019 Ford F350 Lariat, 6.7L Diesel, Dually, Long Bed
    Running with 20k Reese Goosebox (Love It) and Ford Factory "Puck" system.
    Stopping with 8,000 lb Disc Brakes and Titan Hydraulic over Electric Brakes system.
    Powering all this fun with 1200 Watts of Solar, two Tesla, Model S, battery modules, 24 volt Victron Inverter.
    2018 Solitude 310 GK

  4. #14
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    Quote Originally Posted by SolarPoweredRV View Post
    The problem with using a standard Converter with Lithium batteries (LiFePo4) is that the converter uses the voltage from the battery to trigger charging. Unfortunately (or fortunately), the Lithium batteries operate at a higher voltage during the entire discharge cycle (voltage only drops when the battery is almost drained). This higher voltage causes the Converter to not properly charge the LiFePo4 battery and you only get a portion of the energy storage you should. With a Lithium Ready Converter you will get the proper voltages for your Lithium batteries and be able to store the maximum energy for later use.
    Chargers and convertors monitor current being drawn, not voltage. It would be totally ineffective to even try to monitor battery voltage while charging. If they monitored voltage, they'd read their own output and respond to that. Current being drawn is the only useful indication of charge state while charging.
    John & Kathy
    2014 F250 Lariat FX4 6.2L SBCC
    2014 Reflection 303RLS
    SW Indiana

  5. #15
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    Quote Originally Posted by timkoenig View Post
    Actually everything I read said that while you can charge LIFEPO4 on a standard charger the float charge is bad for the batteries. Also to get them fully charged you need a higher voltage. So I replaced my converter and also put in a DC to DC charger that raises the voltage and regulates the charge coming from the truck.

    Also I put the four cells and the BMS in the factory battery box.
    There are three different cell types used for lithium batteries of this class. Rectangular and prismatic cells have a 3.7V cell voltage, but the cylindrical ones have the 3.2V cell voltage. You can't use the same ideas for both cell voltages.

    Cylindrical 3.2V cells make a 12.8V battery which can easily be charged with a standard charger/converter. Many AGM batteries have higher open circuit voltage than that. (as high as 13.2V in commonly available consumer batteries) When you get to the more space-efficient cells that have 3.7V cell voltage, then you need a higher charger voltage since their battery OCV is 14.1V and you can't get the battery to accept much current with a 14.6V charge voltage.

    The float is irrelevant as the BMS shuts off charge voltage when the cells are all charged.
    John & Kathy
    2014 F250 Lariat FX4 6.2L SBCC
    2014 Reflection 303RLS
    SW Indiana

  6. #16
    Rolling Along
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    The timing of this thread couldn't be better. I was going to start a thread similar to this, but I'll piggy back on this one if it works...

    I recently burned up another flooded battery so I made the leap to lithium. My thinking is that the stock converter won't fully charge the lithium battery, but at least it won't hurt it until I can get the proper converter/charger. I am however still confused about the issue of the charger and battery being in parallel. It seems to me that there is no way to separate load and charge current so the charger would rarely "do the right thing" for the battery. Is there a way to deal with this?

    Next is the dc/dc charging problem when connecting to the truck. I see the need and have no problem putting that charger in the system, but I am concerned about the brake actuator function. I would think that chassis ground would be bonded as normal, however... if the trailer positive is at a higher voltage than the truck, that should cause a reverse current in the brake controller causing damage or at least confusing it. At this point I'm afraid to connect the truck with a lithium battery on the trailer.

    How have others addressed this? I've have found no discussion about this on the interwebs so any input here would be appreciated.

  7. #17
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    Quote Originally Posted by Roll With The Changes View Post
    The timing of this thread couldn't be better. I was going to start a thread similar to this, but I'll piggy back on this one if it works...

    I recently burned up another flooded battery so I made the leap to lithium. My thinking is that the stock converter won't fully charge the lithium battery, but at least it won't hurt it until I can get the proper converter/charger. I am however still confused about the issue of the charger and battery being in parallel. It seems to me that there is no way to separate load and charge current so the charger would rarely "do the right thing" for the battery. Is there a way to deal with this?

    Next is the dc/dc charging problem when connecting to the truck. I see the need and have no problem putting that charger in the system, but I am concerned about the brake actuator function. I would think that chassis ground would be bonded as normal, however... if the trailer positive is at a higher voltage than the truck, that should cause a reverse current in the brake controller causing damage or at least confusing it. At this point I'm afraid to connect the truck with a lithium battery on the trailer.

    How have others addressed this? I've have found no discussion about this on the interwebs so any input here would be appreciated.
    Let me try to help you understand the "Parallel" Battery and Converter/Charger Issue...

    First, it helps to not think of the battery/converter connection as a parallel connection, think of it as a "Common", Buss Bar type connection. For example: In my coach the battery is directly connected to a Buss-Bar (after the fuse) then the Converter/Charger is connected to the same Buss-Bar, additionally, the main line that powers the coach accessories is connected to this same Buss-Bar. This configuration creates a "Common" connecting point versus what you are considering a "Parallel" connection. All voltage inputs and accessories/loads are connected to this common buss-bar (PS: this is also where you connect your Solar output to as well). What happens in reality is that electrons flow freely to wherever they need to go, i.e.: if your converter is outputting voltage and you open your slide, the electrons from the Converter are going to flow to the slide motor(s) and if the converter is not producing enough amperage to fully supply the slide, then your battery will provide supplemental power to boost what the converter can supply. Once the slides stop, the electrons from the converter will begin to flow into the battery to replenish whatever electrons it just supplied for the slide operation.

    As far as your concern about the converter "rarely doing the right thing for the battery", the Battery Management System (BMS) inside the battery will automatically control the electrons coming into the battery and will accept as much as it can until the battery is charged and then stop electrons from entering the battery. What your converter does is produce a voltage (13.6 volts DC) the battery accepts all the electrons it can up to that 13.6 number (Lead Acid, or Lithium) once the system reaches equilibrium, the Converter reduces the charging voltage and goes into "Float" voltage 13.2v. This is where the problem with Lithium batteries comes into play because the voltage of Lithium batteries is (almost) always above 13.6 volts which causes the Converter to drop into "Float" mode (13.2v) and your Lithium batteries only get charged up to 13.2 volts versus 14.4v (+/-) when they are fully charged.

    Your other concern regarding the braking from the truck and having a higher voltage is not an issue because the power for the brakes comes directly from the truck and does not go through the coaches 12v electrical system. The only time the coaches 12v electrical system comes into play is when the emergency brake lanyard is pulled, then the 12 volts for the brakes comes directly from the coach battery. otherwise there is no interaction with the trailer brakes.


    PS: Congratulations on making the leap to Lithium Batteries, they are far, far, superior to Lead Acid batteries for RVs.
    David and Peggy
    2019 Ford F350 Lariat, 6.7L Diesel, Dually, Long Bed
    Running with 20k Reese Goosebox (Love It) and Ford Factory "Puck" system.
    Stopping with 8,000 lb Disc Brakes and Titan Hydraulic over Electric Brakes system.
    Powering all this fun with 1200 Watts of Solar, two Tesla, Model S, battery modules, 24 volt Victron Inverter.
    2018 Solitude 310 GK

  8. #18
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    Hello Tim, this is something I would to do soo. We just purchased a 2500rl, actually camping in for 2 weeks for a test run near home. Two questions,

    1- Specifically which Progressive Dynamics converter did you purchase?

    2- Also did the replacement converter fit in the 110 v breaker panel as the old power converter? My current converter is just below the 110 breakers.

  9. #19
    Rolling Along
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    Personally I wouldn't plan on using the stock FLA converter to charge a lithium battery as the sole charger for an extended period of time. It won't push the voltage high enough for the lithium's BMS to equalize the cells, and over time they could become unbalanced. If you have an alternate lithium-capable charger (maybe a solar charge controller, for example) that periodically tops off the batteries, then you could probably go a long time with the stock converter. That's where I'm at right now, since I don't ever use shore power to charge the battery. The converter will only ever get used if I need to use the generator because we ran out of power while boondocking, and it doesn't need to be perfect for that.

    But replacement converter boards aren't too expensive, and pretty easy to replace. I'll eventually replace mine, when I'm done with the other trailer mods and projects I have going around the house. Just a low priority right now.
    Current: 2021 Transcend 261BH, 2019 Ford F250 SRW SWB CC 6.2 - Picture
    Previous: 2016 Jayco X213, 2014 F150 EB 3.5

  10. #20
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    Quote Originally Posted by Dennis1 View Post
    Hello Tim, this is something I would to do soo. We just purchased a 2500rl, actually camping in for 2 weeks for a test run near home. Two questions,

    1- Specifically which Progressive Dynamics converter did you purchase?

    2- Also did the replacement converter fit in the 110 v breaker panel as the old power converter? My current converter is just below the 110 breakers.
    I just got a PD converter to replace my WFCO in my 2500RL. In case GD changed between your year and mine, it's best to go to the Progressive Dynamics site and cross reference a replacement. Look at the model converter you have and cross reference the correct PD lithium charger replacement to get. It will be a drop in replacement.
    2018 Imagine 2500RL
    2016 F150 with 3.5L Ecoboost

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