About a year ago I tested the Power Queen 12.8V 100Ah LiFePO4 battery auto-heating on breaking.
I was very happy with the battery there. It has now been around a year since this test and this year I have constantly used the battery in my DIY solar system.
So I thought it might be a good opportunity to go back to the battery and see how well it has held up this year.
Overview of the Power Queen battery
The Power Queen 12.8V 100Ah LiFePO4 battery with auto-heating is a fairly classic LiFePO4 battery in “car battery style”.
Power Queen is a Chinese manufacturer that offers comparatively cheap batteries. Therefore, the durability was certainly of interest to some people.
In my test, the battery scored points with its unspectacularly good performance as well as the unusual low-temperature switch-off.
The capacity of the battery fluctuated around 105.xx Ah when new.
Durability of LiFePO4 batteries
One of the highlights of LiFePO4 batteries is their durability. Power Queen advertises a whopping 4000~15000 cycles.
This is significantly more than with lead gel batteries! I used to use these for my DIY solar systems and a battery barely lasted more than a year before the capacity collapsed massively.
I have never observed this with LiFePO4 batteries. That’s why I’m such a fan of this type of battery, even if at first glance they are a little more expensive than lead gel batteries.
How did I use the battery that year?
I operated the Power Queen battery with another 100 Ah battery (from another manufacturer) in parallel on a Victron Energy MPPT 100 / 20A charging controller.
The energy came from 2x 380W solar panels and was used to operate various smart home boxes, my home assistant server, etc.
Accordingly, the load was not extremely high, but constant. Loading took place during the day and unloading at night, 365 days a year. In the summer the cycles were of course significantly lower because the charging was faster and more, but in the winter there were 100% cycles from time to time.
So I estimate there were about 365 cycles, varying in depth from 20% to 100%.
Not much for a LiFePO4 battery, but a lead gel battery would have been pretty flat after this time, in my experience (I used up a few of these in the past).
The capacity after one year
Let’s get to the exciting point: how much capacity does the battery still have after a year? A slight loss of capacity would be expected; initially the capacity of LiFePO4 batteries may drop slightly before it stabilizes.
However, after this inherently small but constant load, anything over 5% capacity loss would be “unexpected”.
To do this, I connected the battery to the same charger and measuring device as when I tested it a year ago and got the following values:
Yes, capacity has dropped slightly this year. When new, the battery reached around 105 Ah, and after a year around 102 Ah.
We have a capacity loss of +- 3%. This is not a noticeable amount, quite the opposite! Even after a year, the battery still has more capacity than advertised.
Comparison with the ECO-Worthy LiFePO4 12V 100Ah
A while ago I made a similar comparison with the ECO-Worthy LiFePO4 12V 100Ah.
In this case, the capacity fell a little more after a similar period of time, from 102 Ah to 97 Ah, i.e. by approx. 5%.
Accordingly, the Power Queen battery held up a little better in comparison.
Other battery issues?
Were there any other problems or abnormalities during the year of use? No.
The battery worked absolutely problem-free for me, even in conjunction with the other 100 Ah battery (Creabest). During the entire time, the BMS did not interrupt its function or cause any other problems.
The battery just worked.
Conclusion
We can actually make it short here. I am still very satisfied with the Power Queen battery! This worked absolutely problem-free in continuous use last year and the new test showed hardly any loss of capacity.
In one year the capacity has only reduced by +- 3Ah. This is still above the advertised 100 Ah. Excellent!
Therefore, I can still recommend the Power Queen battery! Sure, my use wasn’t “super hard”, but in my experience, a lead gel battery, for example, would be flat after such a year of use.