PC2 18650 Battery Charger with XTAR QC3.0 18W Wall Charger USB C Port 21700 Battery Charger with USB Output Function for 18650 20700 21700 Batteries-Not Included Batteries

The problem with most of these battery chargers is that the charging mechanisms do not properly charge the batteries, usually undercharging. I have had problems where they will only charge to about 80%. So I tested this with a more sensitive voltage meter after “fully charging” with the product.For my 4.2V battery, it was sitting at 4.17V after the charger said it was finished.This is actually perfect for the battery, roughly around 95%, which actually extends the life of the battery compared to getting 100% everytime. So that gets 5 stars automatically for me for the optimal & safe charging levels.The design is great as well. It is about the size of any standard 10,000 mAh battery charger, so it is impressively compact considering you could get up to 12,000 mAh with the right batteries in it. The magnetic cover is also convenient and it is secure, just don’t drop it from too high up.

While the device has problems accurately displaying the correct amount of battery charge, it does funtion well as a charger and a powerbank. It should be noted that the device gets fairly hot during use and charging.

I like being able to charge batteries at home and in my car on the go and use it for a power bank to. It will charge all 18650s flat top and button top/protected and all 21700s even the longest one’s made with a charging port on the battery like the Acebeam 21700 witch is why I bought this new one because the charging port on 1 of them stopped charging the battery. It will charge 2 devices at the same time and will quick charge if you use the included wall plug or an 18 watt or better if you already have one you can just buy this charger/power bank without the wall plug. (Hope this helps)

Update #2 - DOES NOT WORK - Phone did NOT charge. Actually, it was DISCHARGING, even in low power mode it was blinking on and off. This POS does not work as a charging brick. Steer clear. Based on misinformation in the description and the manual, I strongly recommend steering clear of anything made by XTAR. Wish I could give this product and company 0 (zero) stars.Update #1 - Replacement arrived yesterday. I made sure batteries were 100% charged and hooked up my Samsung phone. For one, display looks fine, but so did the original on the first day. But flickering commenced immediately, just like on the original unit. I changed my phone's charging from fast to slow and it seemed to do the trick. Phone was now charging without drama, albeit slowly. Manual UNEQUIVOCALLY states "The output supports several fast charging protocols". That is NOT true. This unit will NOT work (at least with Samsung phones which are ubiquitous) in fast mode. I would really like for someone from XTAR to come on here and explain themselves - why they are advertising something their units are not capable of doing. I will use this unit for the next couple of weeks, or until it breaks whichever comes first, and will write another update.I had high hopes for this one based on my research, but alas it did not surprise me. It is dead after one use. I charged two 18650 cells with it, and then something went wrong with electronics and only parts of numbers on the display were illuminated. Ok, I can live with that, but when I needed to charge my phone (cells at 100%), XTAR display kept blinking in and out and my phone did not know if it was charging or discharging. I will be returning this product for a replacement because I like the concept. However, my expectation I will get a working unit is extremely low, and that unit will work for more than a couple times, even lower. But I will try. I will revisit this post with an update later. Until then, beware of any XTAR product.

Love it!I have a Nitecore that i normally use to charge 18650's but decided to give this a shot b/c it also had usbc out w/ power delivery. Works fine via the usb3.0 type A too. Charges fast and is a great usb battery pack. I'm using walmart 18650's (made by westinghouse) and I've tested some EBL's as well. I haven't tested my samsung rapid discharge batteries yet, but i suspect i will have no issues.Side note b/c I'm a power geek I love the voltage and ampereage meters. Most people probably only need the percent charged but i like to know when my phone is rapid charging at full capability. I did test charging a chromebook w/ usbc in. I did charge but needed to be in sleep mode for it to work. Considering it's just two 18650's charging my laptop, I'll take charging in sleep mode over a dead battery any day!!

Like others stated some 21700s are very finicky with it, I have to spam push the button for it to realize there's current going in/out and charge/discharge. It also flashes the display a lot so I can't ready any of the info before it goes off so maybe I just got a defective model. Going to pick up some generic 18650s late and test them on it because it truly is a cool product.

I must admit i did not have very high expectations for this battery charger/backup battery but now that I have used it for a while I can really recommend it especially for the techies of the world. The display is great for getting details of the battery state of charge, it is super easy to carry a second or third set of charged batteries and swap out the discharged ones or use it as a charger to charge a set of batteries. For extra capacity it allows you to use the 21700 cells which significantly increase the capacity. The magnetic cover works fine although if it is really getting bounced around would secure it with tape or a Velcro strap. The form factor is not much larger than the batteries so it is pretty compact. Bottom line I find it very useful as both a backup battery and a charger.

Love it. No regrets