We have already looked at some high capacity LiFePO4 batteries. But what if you’re not looking for a high-capacity LiFePO4 battery, but for a cheap, small battery?
Then our today’s test candidate comes into play. As the name suggests, the LiTime 12V 6Ah LiFePO4 battery only has a capacity of 6Ah or 76.8Wh.
This means that this battery is of course not for large solar systems, but rather as a buffer storage for path lighting etc. Let’s take a closer look at the small battery in the test and see whether it can keep the advertised capacity.
The LiTime 12V 6Ah LiFePO4 battery in the test
With 151 x 65 x 94 mm and a weight of 822.5g, the battery is accordingly quite compact, although not tiny. Thus, the battery does not have a much larger capacity than a +- 22000mAh powerbank, but it is still a good deal larger.
It relies on a rather classic plastic housing, as we know it from car batteries, etc.
On the upper side we only have two contacts through which the battery is charged/discharged. In contrast to car batteries, however, this is not a “pure battery”, but has a BMS inside, which protects it from overcharging, short-circuits etc.
The manufacturer gives the following performance values for the battery.
Rated voltage 12.8V
Maximum power (continuous) 76.8W or 6A
Maximum power peak (5s) 15A
Recommended maximum charge current 1.2A
As with most LiFePO4 you can discharge the battery with a maximum of 1C, so 6A. I was a bit surprised by the maximum charge current of 1.2A, which is a bit lower than I would have expected.
This is a maximum of +- 17W with which you can charge the battery, which is a bit low.
LiFePO4 batteries have several advantages over classic lead gel or lithium ion batteries. The two most important advantages are:
Very high cycle stability
Very safe, cannot self-ignite
LiFePO4 batteries are very cycle resistant! You can expect 2000+ cycles. LiTime even advertises 4000 cycles for this battery! Even if it doesn’t say so, these are probably only 80% cycles, but this is still far more than with classic Lithium Ion batteries or lead gel. In my experience, lead-acid batteries hardly last 100 cycles when deeply discharged.
Also, LiFePO4 batteries cannot self-ignite. Even in an extreme situation where all protective mechanisms fail, such a battery should not burst into a sea of flames as Lithium Ion batteries do.
LiFePO4 batteries can also steam and burn, but this is much less extreme. I recommend watching this video https://www.youtube.com/watch?v=Qzt9RZ0FQyM
But what are the disadvantages of LiFePO4?
Bigger and heavier with the same capacity as Lithium Ion.
Must not be charged below 0 degrees
LiFePO4 batteries are bigger and heavier than Lithium Ion batteries with the same capacity, therefore you will never find them in notebooks etc.
Likewise, you must not charge these batteries at temperatures below 0 degrees! Some batteries have a BMS that prevents this. This is apparently not the case with the LiTime 12V 6Ah LiFePO4 battery! You must therefore pay attention manually or use a charge controller that does this.
Let’s move on to the capacity of the LiTime 12V 6Ah LiFePO4 battery. I measured the capacity at 1A, 3A and 6A load.
I fully charged the battery up to 14.6V and discharged it to 10.8V.
Let’s take a look at the measured values.
In my test, the battery reached 5.85Ah to 6.02Ah. This is just under the manufacturer’s specification. Not spectacular, but OK.
Let’s take a look at the voltage curve with a 3A load.
As is usual with LiFePO4 batteries, the voltage curve of the LiTime is also very flat. 90% of the capacity of the battery is in the range of 12.7V and 12.4V. If the voltage falls below 12.4V, it drops rapidly.
Looking for a compact and affordable LiFePO4 battery? Then the LiTime 12V 6Ah LiFePO4 battery is a good option.
It comes +- to the capacity promised by the manufacturer. In my test, it varied between 5.85Ah and 6.02Ah.
But what can you use such a small LiFePO4 battery for? I think it could be used as a buffer battery for a small solar setup, for lighting or pond pumps. Here, the 6Ah should last for a while and the high durability of LiFePO4 can show its strengths.