Lithium iron phosphate hot climates
moltensurf
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
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!
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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.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
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.
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http://members.sti.net/offgridsolar/
E-mail [email protected]
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.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.