Prolonging the life of LiFePo4 batteries

There are many articles and apps for Lithium Ion batteries that show that you can extend the life of your battery by keeping your battery charged between 40% and 80%, not allowing it to drop below 40% and not charging it above 80%.

Does this also apply to Bluetti power stations with LiFePo4 batteries like my EB3A? If I avoid completely discharging the battery to 0% and start charging it at 20% and stop charging at 80% could I expect an even longer battery lifespan than the expected decrease to 80% capacity after 2500 cycles? I understand this isn’t always realistic to monitor so this is more of an theoretical question.

In addition, there’s also the topic of how pass-through charging affects the longevity of LiFePo4 batteries and from what I’m reading this too should be minimized, especially if constantly switching between charging and discharging depending on your AC and DC output loads. Any thoughts on things to avoid doing to prolong battery life?

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Posting here to keep an eye out for the answer. I’m interested as well.

Posting along with Tom to keep an eye on this thread. :slight_smile:

What? Nobody’s gonna make something up here just to answer??? :slight_smile:

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I will…I don’t worry about the lifespan and worry about limiting my usage of the product. I use it how and when I want and know that by the time the batteries are no longer functional, the product will have either failed to function in another area or a newer, higher performing at lower cost product will have been available long before that makes using this product obsolete and it won’t be used anyway.

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I agree! A little bit more “lifespan” at the cost of not using your system they want is crazy. Unless the net gain is so massive why do it? Thanks for the advice.

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I have to admit feeling similar to Scott here. With reports of ‘keep the unit at 80%, or don’t fully discharge to 0%, take it down to only 20%, etc.’, well, I bought the power stations for emergencies to use not only 60% of it’s capacity, but the whole thing. If a blackout occurs, I don’t want to have all my power stations starting out at only 80%, I want full capacity to last as long as possible.

So, maybe experts may say the long term health of the batteries should be in a certain range, and don’t do pass-thru charging, and don’t do this or that, but personally I’ll keep mine topped off to use when needed. I guess whatever is best for each person’s needs.

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I use mine as much as possible and dont worry about keeping it at 80%. I feel guilty when I use the brick to charge it though but who cares. My EB55 is easy to carry outside and hook up solar to but the AC200 max and B230 are in my basement and more of a chore to drag out and hook up solar. I guess I should look into setting up a longer cord from may panels so I can leave it down there.

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I agree. I am in SW Florida and my primary purposes is emergencies caused by weather that could extend for several days. I keep my items stored at 100% as well. I get them out from time to time and run them down to 0% and back to full to verify they are in good working order. I am more concerned about the unit turning on and working when I need it than possibly losing some battery life. I also am not convinced that what we hear regarding battery life is fully accurate. If we something will last for “10” years and XX cycles I don’t know a lot of people that have had LifePo4 batteries and used them sporadically for 10 years and they still function. The possibility of the BMS failing to charge or some other function failing is far more likely to me than worrying about my battery life being somewhat reduced.

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I guess depending upon your use, but with systems getting smarter and programming SOC high and low, you can set specifics using this information, and there’s a lot of info here in this forum at this link:
https://diysolarforum.com/threads/best-lifepo4-charge-controller-settings-known-to-man-for-maximum-service-life-and-minimum-battery-stress-5-000-10-000-cycles.34813/

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Many (not all) of the same principles for prolonging battery life for Li-Ion also apply to LFP. That said, the lifespan of LFP is several thousand cycles to 80%, which is a full cycle a day for 6-8 years in most cases. Unless one is really making bad choices (leaving at 0% for a long period of time, keeping at 100% in hot environments, etc.), it should just last a long time.

As far as the pass-through and how it hits the batteries, I’m sure for models that simultaneously charge and discharge there is some impact, I believe the new EB3A’s UPS “bypass mode” has true passthrough (AC power directly goes to the AC outputs first rather than simultaneously charging and discharging, someone correct me please if that’s wrong).

My units are primarily for home backup so I keep most of them at 90% or more just about all of the time. They aren’t run down to zero, and they are kept in relatively cool places (doesn’t get too hot here often on the Pacific Northwest coast), so I try not to stress about it, but just use it.

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Check out www.batteryuniversity.com they have really good information. Good luck

I have an EB240, EB55 and B300. I am using it on a Fours Wheel s Project M to run a Iceco, fans and lights. (About 152 watts per hour if everything is turned on!) Trying to get an off the grid solution if SHTF.
My plan is use the EB240 and run it down to 20%. Use the EB55 while I charge the EB240 with B300. I solar charge the B300 when it hits 20%. Should be about 5- 8 hours with 500 Watts of solar (Peak).
If I stay in my home I can use the same system for back up. About 6000 watts.

Go to www.batteryuniversity.com they have some great info.

Thank you to all who have contributed to this thread. I went with a Bluetti system vs. building my own for it’s plug and play capability. Portability was also a consideration for me. I am a consumer and in short desire independence from a politically vulnerable grid both at home (charged backup) or if I determine a “bug out” is necessary (portability). My AC300 with 2 B300’s is currently plugged into the grid and is maintaining a 100% charge. Out of the box, my system charged to 100% and immediately when the charge drops to 99% recharges itself to 100%. The only consumption is from the operation of the unit itself. Is there a battery maintenance algorithm in the Bluetti system? Recommended practice for optimal system functionality including system life and operation by Bluetti engineers based on the system design would be helpful for me. There are multiple operational scenarios apparent. Use as a portable “generator” for camping, tailgating etc. Implementation of a home backup such as charged and stored or directly hard wired into the breaker with a transfer switch.

The thread linked by an earlier post states that some most charge controllers are geared towards acid batteries. It states that the float charge is not desirable with LiFePo4 batteries. Is my system doing a float method since it recharges itself when the charge drops to 99%? Can the AC charging be configured for the 20-80% range?

Watching this thread :smile:

From the manual: Would it be a good idea to set the SOC to 20/80 to limit the grid charge to 80%? The system is only plugged into the grid right now.

10.2.2. Time Control UPS Mode
● Set the times of the AC300+B300 to be charged via grid power and the
times to run loads from its battery.
Charge Time: Set the time of when the AC300+B300 is to be recharged by
grid to avoid the higher electricity rates.
Discharge Time: Set the time to switch to batteries to power loads connected
to the Sub Panel (Optional Purchase).
● Parameter Setting:
Battery SOC Low: When the remaining capacity of AC300+B300 is under the
preset High/Low battery capacity, AC300+B300 will stop powering connected
loads.
Battery SOC High: The maximum capacity AC300+B300 can be charged via
grid. Remaining capacity will be charged via solar panels, car, lead-acid battery
or second adapter only.