Hi @BLUETTI_CARE,
I have a Grid Connected EP760 with 2 x B500 batteries that is AC coupled to an existing Solar System.
I would like to know if charging to 100% and discharging to 15% everyday is going to negatively affect the lifespan of my batteries?
I understand that in order to maximise the lifespan of Lithium Iron Phosphate batteries, the approximate recommended maximum charge level should not be over 90% of the battery’s capacity and the approximate recommended minimum discharge level should not go below 20% of the battery’s capacity. Are you able to comment on this statement?
Furthermore, does the Battery Management System in the EP760 already implement these recommended charge/discharge levels invisibly in the background, or is it necessary to manual change the Working Mode - SOC Setting to “20%-90%” to achieve these recommended levels?
Note that within a day, my EP760 could also be discharging/charging in smaller cycles based on current solar generation and load changes but post sunset, the battery discharges overnight while supplying night time loads.
Thank you for any advice,
Lyndon
Hi @Lyndon_S
i cant fully answer your question, since i dont know about the invisible limits, but there is one important thing about the “Not 100% Charge”. In general its right that batterys dont like to stay at 100%. But Lithium Phosphate batteries actual sometimes need to be on 100% for cell balance. So never charge them to 100% would be also wrong.
greetings
Erik
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Hi @Lyndon_S, Based on your needs, we recommend setting the SOC to 20-90%. Once it reaches 90%, the solar energy will charge it up to 100%. This is similar to how we charge our phones.
Thanks to @Selfmadestrom for the insight, it was very helpful.
Hi @BLUETTI_CARE,
Thanks for the quick response. Can you please clarify what you mean by “Once it reaches 90%, the solar energy will charge it up to 100%”?
I would have thought that if I set the maximum SOC to 90% - doesn’t that stop the battery from being charged above this 90% level?
Note that on my system I have disabled charging from the grid so all charging on my batteries is from solar generation.
Finally, can you confirm that the battery management system does not automatically implement any strategies to prolong the life of the batteries???
Curiously,
Lyndon
Hi @Selfmadestrom,
Thanks for the advice.
The max SOC setting doesn’t stop the EP760 from charging to 100%. Do you know of any other way to control max charge level?
The min SOC setting seems to work sometimes, but intermittently, the charge level drops to below this minimum setting.
As a user, we should be able to set these levels to give our batteries a maximum lifespan.
Kind Regards,
Lyndon
Yes, thats correct. Like BLUETTI_CARE mentioned, the SoC Setting just defiened how much of the SoC is filled by grid power and how much by solar. Its not a real limiter. If you set your SoC to 80%, that just means that between 80% and 100% only solar power is used.
Im with you. You buy the product and you should be able to limit the SoC like you want.
The good thing is, the EP Series often get new functions. Maybe this is one of them in the future.
greetings
Erik
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Hi @Lyndon_S, Thank you for your additional information.
Since your EP760 is not connected to the grid, setting the maximum SOC is not necessary.
Please continue to charge and discharge it daily as you did before. Rest assured, the app has a battery maintenance feature.
To extend the battery’s lifespan, please manually recalibrate once every six months, and charge the battery as soon as it runs out of power.
Thank you to @Selfmadestrom for the response, this makes perfect sense.
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@BLUETTI_CARE
My EP760 is connected to the grid but configured not to charge from the grid.
What version of the Bluetti app has the “battery maintenance feature”? Can you provide any details about it please?
Lyndon