OSUNLIN Rechargeable Hand Warmers, 5200Ah/7800Ah Portable Pocket Hand Warmer, Electric, Quick Heating, Great for Skiing, Climbing, Hiking, Winter Gift

I'm changing a previous review. Mike from Ronnie Tech sent me a replacement power bank, and I tried it out over the weekend. In my testing of the previous power bank, the best trial used nearly 60 percent of the capacity of the power bank to charge my Samsung S4 from zero to 100%. The worst trial used a little over 70%. The difference in the extremes was probably the use of a better cable.The replacement power bank, after completely discharging the power bank then charging it to 100%, charged my phone from zero to 100% using 38% of the capacity . My wife's phone is the same make and model, so we could easily charge both phones and have enough capacity left to bring one to about half full.In the process of completely discharging the power bank initially, I used it to power an Amazon Dot to play music in our garden, and there was enough capacity left to power my grandson's 5" RCA tablet for a couple of hours. He was most disappointed to learn that he could not surf the internet on multi-hour road trips. Shrug - he's barely five. There will be more disappointments of a greater magnitude in his future. I'm just glad that I used his tablet rather than his game boy.In closing, Ronnie Tech showed that there is another component to consider, aside from technical specifications, when purchasing an item in an internet marketplace. Customer service is even more important in an environment where a vendor only needs to change their name to escape a poor history. In this instance, their customer service trumped their product. I would award more than 5 stars if possible :)

Edit: Originally I gave this 5 stars, but the 2.1amp port malfunctioned and does not work. I was able to get a replacement under the warranty but my replacement doesn't even work correctly. Yes it charges, but it is not a fast charge output, even with different cables that are rated for fast charging. Kinda sucks needed it plugged in for 2-3 times longer when the battery should just function normally in the first place. So I've noticed a lot of other people had problems with the 2.1A output port as well. The QA for this company must not be good. My battery also makes a white noise sound when charging. I've also noticed this battery does not hold a charge as well as it has stated. I should be able to get 3 or 4 charges out of the battery but only get 1-2. I may just shell out more money for a better charger next time.Works perfectly and comes in handy. I 3D printed a custom clip so it attaches to my phone easily. I can charge usually about 3-4 times before I need to recharge it. The fast charge port helps a lot. Great portable battery for the price.

Had high hopes for this one. When I opened it up I was very impressed with the build quality, looks, feel, and features. I have 5 different brand of portable battery packs and this one was my first with a digital battery gauge so I was a little bit excited. However after 4 full test on my Nexus 6P I quickly realized that capacity of this pack which was rated at 12,000mah was not correct. I did 4 full charges from 5% range on my Nexus which is 3450mah to 100% without touching the phone and this would leave the battery pack with 25% capacity left each time. I should be able to get a little over 3 charges if I didn't use the phone while charging. Maybe I got a dud but the capacity seems more in line with 6000mah. Keep this in mind when you make your purcahse. While it is slim, pretty, and feature packed its not all what its made out too be.

I bought one of these 7800 mah heaters over a year ago, and I just bought another for my wife. Sometimes the workplace is cold. I put this in my shirt pocket, and it helps. If I leave it on the low setting, it will last just about the entire 9 hours. My coworkers love to borrow it from me. The bigger number of mah or ah means more stored power so it's worth the extra money.

The first one I bought actually came defective. However, I contacted the seller and after a very brief troubleshooting he agreed and sent another one within a day of notifying him! Second one works without a hitch so far.Some observations:-This battery pack will charge 3-4 iphone 7/6s/6 or Samsung Galaxies (my friends and I have a mix of phones)-This battery pack does not heat up at all while charging or discharging. I was impressed by this considering even my previous Anker battery pack would get warm while charging/discharging-On quick charge, mine will take anywhere from 1 hour to 3 hours to charge fully from 0 to 100. Not a big deal for me since I charge it the day before I need it.Overall an excellent purchase and a great price when it's on the lightning deals!

I should've known this would be too good to be true for $19.99. It looks great, sleek and not bulky. Tho the production details were rough... the faceplate seemed like it was going to fall off & there was glue or some sort of adhesive coming out from behind the faceplate.Technical Issues:1. The USB ports are SOOOO tight that I could barely plug into & then remove plugs from them. Didn't feel like they would last very long.2. It will not charge! I've tried diff cables & wall chargers. left it overnight & woke up to zero increase in charge.3. Users manual warns to not leave devices plugged in after they are fully charged in order to prolong the life of your devices battery. The description on Amazon says safe from overcharge! No thanks, I'd rather not fry my devices.Wanted to love this. And I am willing to believe that it is possible to get decent quality for a bargain price... but not with this item. I have already ordered an Anker charger to add to my line of smaller Mophies.

This is my 2nd Polanfo battery. 1st one i bought was in April this year and i liked it so much so when this went on sale, i didnt hesitate to buy another 1. The battery is great. It feels durable since the outside is not plastic but of course this also means its not light weight. What i like about it is the display so i never need to guess how much battery you have left. It also holds a good amount of charge, enough not to have to recharge the power bank everyday. I usually use this to charge the note4 and gear watch and i like that it charges fast. Definitely a great buy.