Lithium iron phosphate hot climates

moltensurfmoltensurf Registered Users Posts: 5 ✭✭
I have a ram pro master I am fitting  out with solar. I am trying to keep the weight down in my vehicle and would like to use lithium iron phosphate batteries. I travel a lot in hotter climates, and live in southern Texas. My van is well insulated, but I hear the lithium batteries do not like heat, and work better in cooler climates. Does anyone use lithium batteries to travel in hot climates? Should I go with another type of battery bank?

Comments

  • Dave AngeliniDave Angelini Solar Expert Posts: 5,547 ✭✭✭✭✭
    I assume you are not talking about a starting battery. You should look at what the battery brand says about life in an RV. That is what you have right?  Also search the brand for RV people using that battery over time. You want old users in the southwest. I would only  look at LFP chemistry (lithium iron phosphate) as NMC used in cars is much more dangerous.

    In general LFP batteries get the longest life at temperatures that humans like. Many measure temp/cycles for warranty.
    Since it is so easy/cheap to buy flooded batteries at places like costco and all the others, I would look at price before lithium.

    Lithium batteries do not like cold and that is the main reason they measure temp. If you charge on below 32F you can easily kill it.
     Yes, and just one time!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • mcgivormcgivor Solar Expert Posts: 3,600 ✭✭✭✭✭✭
    Welcome to the forum @moltensurf

    Quite the contrary, LiFePo4 are more comfortable in higher temperatures than their lead acid counterparts, for this reason I abandoned lead acid in favor of LiFePo4  as the temperatures where I am rarely drop below the optimal value  for lead acid which is 25°C. 

    Being more in the mid 30°C plus ambient, my observations are that LiFePo4 run cooler, due to their inherent .efficiency being close to 98%, as opposed  to 80% for flooded lead acid, which manifest heat over time and have trouble dissapating the  heat due to shear mass. 

    The downside of LiFePo4 is when temperatures drop to freezing  0°C or below. The optimal temperature for LiFePo4  is 30°C, making them suitable in warmer environments, if below freezing not predicted  then LiFePo4 is the way to go.

    Disclaimer, I've no experience with AGM lead acid  but would assume the results would still be In favor of LiFePo4, all things considered.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • moltensurfmoltensurf Registered Users Posts: 5 ✭✭
    @mcgivor Have you ever traveled into the extreme cold with your batteries. I don’t live in the snow but sometimes go there. Thinking maybe battery bank could be put inside of an ice chest to keep it at a reasonable temperature?
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,547 ✭✭✭✭✭
    He is in Thailand I think.  It is not just the cold which is why I suggested you pick a battery make and research it. I have had clients damage LFP in high heat. They will withstand it longer than cold. Read the warranty. Due diligence is on you to not just trust what people write here.
    The store here on the site sells several LFP that might work for you. 

    You will be spending up to 4 times what a flooded battery will cost and 3 times what an AGM will cost. You really want to make sure you have the knowledge to make the risk worth the reward. If you are traveling make sure you can get a replacement. Pretty hard to not find a Costco in North America.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • moltensurfmoltensurf Registered Users Posts: 5 ✭✭
    @Dave Angelini I am pretty handy, and there are lots of resources online to build batteries.  I was thinking of perhaps making a battery.  I used to live on a sailboat for many years, I ran solar for most of my power. My battery bank was pretty heavy. I had golf cart batteries wired to twelve volts. I had 6 batteries in total. 
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,547 ✭✭✭✭✭
    Sailed 18,000 miles myself but in those days solar was for satellites. Sounds like a good project for you but you have to insulate well for cold. Good Luck. 
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • mcgivormcgivor Solar Expert Posts: 3,600 ✭✭✭✭✭✭
    @mcgivor Have you ever traveled into the extreme cold with your batteries. I don’t live in the snow but sometimes go there. Thinking maybe battery bank could be put inside of an ice chest to keep it at a reasonable temperature?


    The batteries have never been subject to temperatures below 20°C as I'm in Thailand, the mean average is 27°C but during the months of April and May it's more like 35°C average with highs of 40-50°C.

    When using lead acid during the hot months the battery temperature would manifest over time to be at a constant 40°C+, due to the thermal mass and high overnight temperature they were unable to cool. Because FLA batteries are ~80% efficient, 20% of whatever is put into them is wasted as heat in the batteries themselves, adding tu the challenge of high ambient temperatures.

    Had experimented with water bath cooling which was successful in itself but attracted animals, including snakes, seeking a drink as it is extremely dry at that time of the year. This added complexity prompted me to look into LiFePo4 as a possible solution, because without cooling FLA show signs of deterioration after about 500 cycles ultimately failing at about 3 years.

    The replacement  DIY LiFePo4  bank of equal capacity, 400Ah at 24V nominal,  was about twice the cost of FLA including the BMS, they have been is service for 2 years without any problems, even during the hot months the battery temperature remains below ambient sometimes by 10°C, because of their inherent efficiency of 98% they don't self heat to the same degree being they have 75% less mass, this allows overnight cooling.

    There are other benefits which came as a bonus, they can charge at higher currents without the need for long absorption, discharge at high current without significant voltage drop, tolerate partial states of charge without negative impact, have a larger usable capacity, smaller footprint with less mass,  are protected at a cellular level via BMS and are essentially maintenance free. 

    Well worth the money all things considered since the life expectancy would likely exceed 3 sets of FLA given the environment they are subjected to here, so actually cheaper, time will tell.  Lead acid batteries do not like heat, LiFePo4 do not like cold, both work best at 25°C choose what's best for you. Fully intergrated LiFePo4 battery systems with communication are available at higher cost which may be better suited to some.





    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
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