If you live in an area where city power is rather unstable, you tend to grow quite conscious about electricity availability. Now, unless you plan to go completely off-grid which is a large investment on its own, all you can do is purchase UPS and some power banks to keep what you consider essential online when power goes out.
UPS has traditionally been bulky, very heavy, and rather unreliable. It is no fault of UPS itself. Rather, the fault lies on its battery which is 99% lead acid battery.
Things are slowly changing though as of 2020. Lithium ion and, especially, Lithium Iron Phosphate (LiFePO4) batteries are making their way into consumer market at affordable price points.
Both types of batteries, in this case lead acid battery and Lithium ion, have pro and con. However, lead acid battery isn’t really meant for UPS. It works, yes, but it’s not very efficient and reliable. I am not going to go too deep on the matter here but lead acid battery isn’t ideal for UPS for following two reasons.
- Discharging lead acid battery below its 50% of its advertised capacity is not recommended as it will damage the battery, meaning, if your UPS has a 108 Wh (a typical 9Ah battery at 12v), your real capacity is only 54Wh. If you add power conversion loss from DC to AC which is typically 15% at the least, you can see how little of juice you actually have at your disposal. Of course, you can ignore this but doing so will significantly impact the battery lifespan.
- Lead acid battery does not like fast discharge. However, in many cases, it is discharged rapidly due to being hooked up to a beefy machine.
There are more reasons but above two are my primary reasons for looking alternative UPS technology.
Enter TalentCell Mini UPS, rated at 98 Wh and has a capacity of 27,000 mAh @ 3.7v. Its batteries are Lithium ion, the cheaper, thus more affordable, kind. Lithium ion generally have 500 life cycles which is about the same with lead acid battery you find within a traditional UPS.
Unlike lead acid batteries, Lithium ion battery capacity is as advertised. It is safe to discharge well below 50%. It is NOT recommended to fully discharge it but using 90% of its advertised capacity will have no ill effect. It can also handle fast discharge. Its voltage will drop but that happens with every battery type.
The TalentCell Mini UPS is basically a beefy powerbank with a passthrough function. Almost all powerbanks do not have this function. What it does is that the unit will stop charging its battery once it’s fully charged and pass power to connected units directly. According to its manual, it will let the battery idle until its charge drops to a certain point and it will charge it back up. This will preserve its battery life.
If power is lost, it will automatically, and seamlessly, use its battery to supply power. This is effectively what a UPS does. The unit has four 12v DC and one 9v DC outputs. It has no AC outlet. It’s DC only, so its application is limited. However, it is advertised for routers, modems, CCTV camera, and such which would fit the bill.
Let’s measure its voltage at full charge. This part is important for few reasons. You want voltage from DC output to be stable. It will drop, for sure, as the battery drains but, if it goes too low, it might shut down connected units. The only way for 12v DC to be stable is when the output is regulated which I doubt this unit is. I mean, look at the header image where it shows its spec. The label says “9v to 12.6v” for 12v DC. 9v is kinda a little too low for my taste though. So, let’s see whether it goes really that low.
12v DC reads at 12.26 volt. 9v DC reads at 9.32 volt. It is looking good. However, do remember that this is at full charge. I am going to drain its battery to its last bar; there are four power dots with each indicating 25% of charge. Then I will measure its voltages again.
I can’t say I am too surprised. At one power dot (less than 25% charge left), we are looking at 9.82v from 12v DC and 9v from 9v DC. My router still worked at this voltage though. I reckon the voltage will hit close to 9v at really low charge.
Let’s open it up and see what’s inside next.
I see 12x TNL-ITR 18650 AF battery. Googling the part number doesn’t yield a good result but there is an Aliexpress listing that shows TNL-ITR 18650 STP with 1,300mAh rating. I do not know the difference between AF and STP here. If I go by the 1,300 mAh rating, this unit has 15,600 mAh @ 3.7v which is far cry from advertised 27,000 mAh.
What seems certain is that TNL appears to be a Chinese company which isn’t generally a good sign when it comes to lithium ion batteries. However, the unit itself works fine and it took almost 2 days for me to drain the unit with a USB light. I wish I had something better to drain the battery, but this is my first in-depth battery review and I am lacking tools.
Do I recommend the unit though? I can’t say at this time. I am going to hook it up to my router and see how it works. It will take several months for me to make a proper judgement as well as a proper power outage in addition.
What I can say for sure is that you don’t find many lithium ion UPS on consumer market. For me, this is the only lithium ion UPS I can get my hands on. And beggars can’t be choosers, most of time.
Finally, even if the true mAh is indeed 15,600mAh, it should power a router for hours which is the main reason for me to have purchased this unit, so I will see how it goes.
Update 2022 April: It died.
I found out that it died after it failed to power my router during a recent power outage. Upon a quick autopsy, I found that the batteries are completely dead. Well, I am not too surprised to be honest. New, healthy, cells shouldn’t die after 2 years of minimal usage. It is either that the cells were not exactly new, I mean they even lied about its capacity, or that the unit was charging cells wrongly.
Either way, it’s dead. I am not buying another unit because I no longer trust them.