I have real life data of two different packs: 1st is a 7 year old LiPo pack which had a manufacturer warranty of 500 cycles to 80%SOH. That pack is inside a 28 deg indoor room and cycling once a day. Now I have actual 2000 cycles and the SOH is 80%. So this Lithium-Polymer cells have performed well better then the specification! 2nd is a 4 year old LiFePo4 pack which was built out of second hand Sinopoly first Gen cells. The cells had been around 2 years old when I got them, so I guess they had around 1000 cycles already maybe from an challenging automotive application. I have added another 1200 cycles in a solar setup by charging/discharging them once per day. The place is outdoors but enclosed. Temperatures will be around 35 deg average. The cells are now at only 50% SOH and further degrading by 10% a year! So this Lithium Iron Phosphate cells performed far worse then specified and will have to be replaced soon, but that is probably because I didn't have the chance to get new cells that time. My advice is to always buy new cells and treat them good as specified. Do not push them to hard, don't expose them to harsch environmental conditions. Use common sense and don't try to push limitations by saving a few bucks!
The degradation curve is not linear. After 80% it goes steaper downwards. So the example with the used Sinopoly LiFePos is quite a bit speculative I guess ; )
@topeye4202 it would take me 30 years in my solar application to reach 10000 cycles. So any prediction or claim about SOH even with new cells would be speculative :))
@@RolandW_DIYEnergyandMore The claim "they performed far worse than specified" is not true anyway, cause they are specified in the range till they reach 80% only and how many cycles were needed to reach 80% is unknown, maybe there was as many cycles they claim in specifications.
@@starmaxenergy u know what also would be AWESEOME, if the company would test ALL CELLS for REAL CAPACITY and print that on the cell, because not all cells are made equal???
The 15mm compression plate is also a very large heatsink. thus reducing the temperature of the battery it was also probably actively cooled. the 30 minute rest allows for internal temperatures to dissipate. Thank you for your illuminating video.
Problem is the ally plates are at each end where no cooling is required. The slotted busbars allow for 5mm between cells if you can find some non conducting rigid but hollow material about 5mm thick cut to size and placed between each cell that will allow heat to dissipate and act as an insulator. If your lucky you can drop temp probe down the hollow and get a more accurate reading at the centre of the batteries.
I have the problem to make the batteries hot enough... I've noticed that once I go above 0.1C I can finally get them a bit warm. But my circumstances lead me to decide to forfeit heating pads, because my batteries would be inside an insulated building before the end of this year. Now I have ordereded extra battery boxes with heating pads, because the insulated building does not exist yet. Just insulating the batteries is not enough, I really have to charge them with 0.2C to get them warm enough. In normal off-grid use, they shouldn't get warm though: the solar/battery balance should be around 0.1C.
At 0.5C charge and discharge, each cycle takes 4 hours. 10,000 cycles = 40,000 hours > 4.5 years. I doubt they have actually tested any cells for 10,000 cycles. 10,000 cycle life must be extrapolated from a much smaller number of cycles.
The number of cycles on the specification sheet is inferred from the manufacturer's data curve and is not a true experimental test of 10000 times. Because Hithium has not been established for 5 years
If the degradation curve is somewhat linear it's easy to determine after 6 months how long it would be when the battery would only be at 80% capacity. My whole home solar 70kwh battery only uses 65 ish cycles a year. They will calendar age faster than cycle age
Hi Enya will you be stocking EVE LF560K when they are released? I see lots of adverts on Alibaba but when you enquire they never have stock and want to sell you 280... it's called false advertising and should not be allowed.
@@reginaldpotts2037 Hi Richard, 560ah is still in the experimental stage and is not in mass production yet. Once this battery is put into mass production and released, I will give you a review and analysis as soon as possible.🤗
I have a 280A battery that I haven't used since I bought it, about two and a half years, what is the correct way to charge it? I have a 5 amp charger and I have a 50 amp, which one is more suitable?
It is recommended to first use a low current 5A charger for 2 cycles of charging and discharging, and then use a high current 50A charger for charging and discharging. If a battery that has been stored for a long time is charged and discharged with high current, it is easy to cause the problem of battery bulging/swollen. Hope this can help you ))
Estimation formula: Heat generation=discharge energy of battery - chemical energy of battery; Or Q=I ^ 2 * Rt (Rt is the internal resistance of the battery). The I goes larger, the heat will higher
@@starmaxenergy HI, you have to mention, that cells , that are long time, at 90 - 100 % SOC at high temps, not only degrade with respect to capacity, they can have 95 % of capacity of new cells, but DC resistance and AC impedance of the cell, will be so hight, that cheap 2 A BMS, can not balance this large battery pack and you need to invest time to build DIY active BMS with 32 temp sensors and 30 A active balance current. Also properly mannufacture cells do not need compression, I have a lot of cells from 2013 - Winston and I have no problem after 12 y. and a few thousands of cycles, I try to use cell, like university prof. like Jeff Dahn advice. The is a lot of pdfs at scientific level, that can user read, and set MPPT / charger / IN|VERTER + BMS, so that he can achieve max. performance for 20 - 30 years of service life, the user and user knowledge and BMS and inverter manufacturers knowledge is the problem, not LFP cells,
EXCELLENT JOKE about grandpa's battery still works X-D (would be AWESOME and even more people would buy if possible) but problem: most of EU the temperatures (outside) are below 5°C in winter (bad for battery when charging?)
Dear, low temperature can cause a decrease in battery capacity, an increase in internal resistance, a decrease in charging and discharging efficiency, and a decline in cycle life. For example, the capacity of lithium iron phosphate batteries at -20 ℃ is only about 60% of the capacity at 15 ℃.
I have real life data of two different packs:
1st is a 7 year old LiPo pack which had a manufacturer warranty of 500 cycles to 80%SOH. That pack is inside a 28 deg indoor room and cycling once a day. Now I have actual 2000 cycles and the SOH is 80%. So this Lithium-Polymer cells have performed well better then the specification!
2nd is a 4 year old LiFePo4 pack which was built out of second hand Sinopoly first Gen cells. The cells had been around 2 years old when I got them, so I guess they had around 1000 cycles already maybe from an challenging automotive application. I have added another 1200 cycles in a solar setup by charging/discharging them once per day. The place is outdoors but enclosed. Temperatures will be around 35 deg average. The cells are now at only 50% SOH and further degrading by 10% a year! So this Lithium Iron Phosphate cells performed far worse then specified and will have to be replaced soon, but that is probably because I didn't have the chance to get new cells that time.
My advice is to always buy new cells and treat them good as specified. Do not push them to hard, don't expose them to harsch environmental conditions. Use common sense and don't try to push limitations by saving a few bucks!
The degradation curve is not linear. After 80% it goes steaper downwards. So the example with the used Sinopoly LiFePos is quite a bit speculative I guess ; )
@topeye4202 it would take me 30 years in my solar application to reach 10000 cycles. So any prediction or claim about SOH even with new cells would be speculative :))
@@RolandW_DIYEnergyandMore The claim "they performed far worse than specified" is not true anyway, cause they are specified in the range till they reach 80% only and how many cycles were needed to reach 80% is unknown, maybe there was as many cycles they claim in specifications.
Great education
EXCELLENT VIDEO WELCOME BACK :D (+educating by +smart woman (0% of women in EU care about batteries :(
Thank you my friend, I will try to bring more for reference.
@@starmaxenergy u know what also would be AWESEOME, if the company would test ALL CELLS for REAL CAPACITY and print that on the cell, because not all cells are made equal???
The 15mm compression plate is also a very large heatsink. thus reducing the temperature of the battery it was also probably actively cooled. the 30 minute rest allows for internal temperatures to dissipate. Thank you for your illuminating video.
Problem is the ally plates are at each end where no cooling is required. The slotted busbars allow for 5mm between cells if you can find some non conducting rigid but hollow material about 5mm thick cut to size and placed between each cell that will allow heat to dissipate and act as an insulator. If your lucky you can drop temp probe down the hollow and get a more accurate reading at the centre of the batteries.
thank you fo information
Star max is the best. Thanks jack for you good service 👍
Cell life should be measured in kWh or Ah
I have the problem to make the batteries hot enough...
I've noticed that once I go above 0.1C I can finally get them a bit warm. But my circumstances lead me to decide to forfeit heating pads, because my batteries would be inside an insulated building before the end of this year.
Now I have ordereded extra battery boxes with heating pads, because the insulated building does not exist yet.
Just insulating the batteries is not enough, I really have to charge them with 0.2C to get them warm enough.
In normal off-grid use, they shouldn't get warm though: the solar/battery balance should be around 0.1C.
At 0.5C charge and discharge, each cycle takes 4 hours. 10,000 cycles = 40,000 hours > 4.5 years. I doubt they have actually tested any cells for 10,000 cycles. 10,000 cycle life must be extrapolated from a much smaller number of cycles.
The number of cycles on the specification sheet is inferred from the manufacturer's data curve and is not a true experimental test of 10000 times. Because Hithium has not been established for 5 years
If the degradation curve is somewhat linear it's easy to determine after 6 months how long it would be when the battery would only be at 80% capacity. My whole home solar 70kwh battery only uses 65 ish cycles a year. They will calendar age faster than cycle age
Compare between nmc vs lfp battery
how is it with import tax to EU? when buying 16x cells how much is import tax?
Tem estoque no Brasil 🇧🇷 ???
Hi Enya will you be stocking EVE LF560K when they are released? I see lots of adverts on Alibaba but when you enquire they never have stock and want to sell you 280... it's called false advertising and should not be allowed.
@@reginaldpotts2037 Hi Richard, 560ah is still in the experimental stage and is not in mass production yet. Once this battery is put into mass production and released, I will give you a review and analysis as soon as possible.🤗
I have a 280A battery that I haven't used since I bought it, about two and a half years, what is the correct way to charge it? I have a 5 amp charger and I have a 50 amp, which one is more suitable?
It is recommended to first use a low current 5A charger for 2 cycles of charging and discharging, and then use a high current 50A charger for charging and discharging. If a battery that has been stored for a long time is charged and discharged with high current, it is easy to cause the problem of battery bulging/swollen. Hope this can help you ))
@starmaxenergy thanks
At 0.5C there will be very minimal heating of the battery.
Estimation formula: Heat generation=discharge energy of battery - chemical energy of battery; Or Q=I ^ 2 * Rt (Rt is the internal resistance of the battery). The I goes larger, the heat will higher
@@starmaxenergy HI, you have to mention, that cells , that are long time, at 90 - 100 % SOC
at high temps, not only degrade with respect to capacity, they can have 95 % of capacity
of new cells, but DC resistance and AC impedance of the cell, will be so hight,
that cheap 2 A BMS, can not balance this large battery pack and you need to invest time
to build DIY active BMS with 32 temp sensors and 30 A active balance current.
Also properly mannufacture cells do not need compression, I have a lot of cells from
2013 - Winston and I have no problem after 12 y. and a few thousands of cycles,
I try to use cell, like university prof. like Jeff Dahn advice. The is a lot of pdfs at scientific
level, that can user read, and set MPPT / charger / IN|VERTER + BMS, so that he can
achieve max. performance for 20 - 30 years of service life, the user and user knowledge
and BMS and inverter manufacturers knowledge is the problem, not LFP cells,
EXCELLENT JOKE about grandpa's battery still works X-D (would be AWESOME and even more people would buy if possible) but problem: most of EU the temperatures (outside) are below 5°C in winter (bad for battery when charging?)
Dear, low temperature can cause a decrease in battery capacity, an increase in internal resistance, a decrease in charging and discharging efficiency, and a decline in cycle life. For example, the capacity of lithium iron phosphate batteries at -20 ℃ is only about 60% of the capacity at 15 ℃.
Maybe 2000 cycles, but 10000 its bull sheet