+1 vote for this feature. I have my generator in a remote location I vist once a month or less. Keeping it at 80 while not there and using 100% when I am should extend battery life
I recently bought my new AC200P L and was disappointed to find that there’s no charge limiting feature. Even my two-year-old EcoFlow had this capability. I don’t think constantly charging to 100% is going to be good for the battery, right?
I’m going to put out another point of view on this topic.
The first thought is that the BMS never allows the batteries to actually get to 0% charge, or to 100% charge. I believe there is around a 5% to 10% capacity on each end of the spectrum that is “untouchable” to the device use. Meaning that 0% or 100% represents the usable capacity of the battery as constrained by the BMS in the device.
The chemistry of LiFePO batteries is quite different from “standard” lithium batteries, and they handle cycling of charge storage much better, and do not have any memory effect.
The Bluetti power stations, while having a range of cycle capacities, are normally capable of being cycled 3,500 times from 0% to 100%, per the displayed state of charge. That is pretty much a full charge from 0% to 100% every day for 10 years. And after those 10 years you will still have 80% of the capacity of the battery available to you, to keep cycling with.
The longevity of this battery type is so vastly superior that it no longer makes sense to try managing them in the same way as the older technology. By the time 10 years is done there will be vastly superior devices around, and it will be time to upgrade (or just keep using them for another 10 years).
Just use them, they can handle it.
5 Likes
Oh, it’d be fantastic if the BMS did that on all battery-powered appliances. My smaller devices like earbuds typically lose 60%+ or their capacity over the years, as it’s difficult to manually manage the charge levels there - sure, they use a LiPo and no LiFePO4, but still.
From what I remember there were a whole bunch of standard tests for different powerstations: Getting their exact capacity from the hardware, measuring input Wh for a full 0 to 100 charge and for a full 100 to 0 discharge (AC/DC). The EB3A got a “normal” (efficiency) score there, indicating that the full capacity was used without a reserve on either side of the charge.
LiFePO4 batteries are more robust than LiPos for sure, and it’s true that a lot of people treat their devices as a basic commodity that they’ll replace in a few years anyway. There the battery wear doesn’t really matter.
I prefer avoiding battery wear when not necessary and keep devices in good condition for longer usage periods. When I need the full capacity then I do the full 100% to 0% cycle, that’s what I have it for. When I don’t need to full capacity - either for UPS usage or storing it for a bit - I prefer a state of charge that minimizes wear on the battery.
I think I even read on some Bluetti documentation that storing the powerstation at 100% leads to quite a bit of battery drain that reduces the capacity temporarily, which can be mostly reversed with a few full charge/discharge cycles.
I have recently bought 2x of AC180P to complement Ecoflow Delta Max at different locations. Significant capacity to be prepared for longer outages (I live in Ukraine). However, usually we have 2-4 outages a day for 2-3 hours in winter and summer.
In UPS mode it would be super-useful to prevent multiple 80-100% cycles a day. So:
- start charging only if charge is below e.g. 30%.
- I’d still like to prevent full cycle to 100% unless there is strong evidence LiFePo batteries are fine with that.
- Avoid charging during peak hours (morning and evening) to reduce stress on energy system. Some may like charging at night.
- Ideally, allow nightly charging from e.g below 50%, while daily - from below 30%, thus prioritizing night time.
When I was ordering it, I watched few videos online and was sure it is already possible with Bluetti - so chosen it over Ecoflow. However, I’m a bit disappointed with low amount of control over charging.
I really hope it can be fixed by just app/soft update. And that’s a really small one!
Just do it for those who need it!
2 Likes
+1 on this feature, and hijacking the topic, the feature to AC output last state.
1 Like
I have an EB3A, and after that I had to buy two more stations and I switched to another brand precisely because of the lack of this feature. It is necessary to be able to limit the charging and discharging of the batteries to a limit defined by the user.
In addition, another brand also provides Wi-Fi on the equipment, which allows monitoring and making adjustments through the application using the Internet.
Someone always says this, but there are sound reasons for not maintaining any lithium technology at a constant 100% float. But without getting into it, if you don’t believe this then you simply don’t have to activate the feature.
Just let me have a slider to decide maximum and minimum charge percentage. Intending to use my AC50B as an ups for a fridge. This is a must have if it’s supposed to last for a long time!!! I might return it and exchange for ecoflow, because for only a bit more money they have that and I would save in a long time by not having a new one sooner.
+1
The option to limit to 80% (or any other value) would be fine.
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I’m wondering why there is no comment from @Bluetti,
with the exception of that from September 2022 at the beginng of this thread
(which does not touch on the heart of the matter).
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Are there limits internally set by the BMS of e.g. 10% and 90%
which the display shows as 0% and 100% as @hnymann assumed?