Surface Pro 4 External Battery - 96 Watt-hour Extended Pack for Windows Microsoft Tablet Surface Pro 1 2 3 4 & Surface Book - Includes 4 USB Ports, AC Adapter & Accessories in Bundle

Does the job

Not great at all. Loved this product when I first brought it, however, less then 7 months later its broken. Just keeps powering off as soon as I try and charge anything. Real shame. Waste of money for the price. I would expect it to lose some of its charging level over time but not like this. I have only used it to a discharged level 7 times. Possibly a faulty product but still not happy. I wasted so much money on it.

This is a replacement for a much larger 100AHr battery that was taken off me in an Aeroplane. The latest rules are that the battery must be less than 100WHr. This one was rated in the description to be 98Whrs. HOWEVER, and please take note: It has 28AHrs and with an internal battery at 3.7V so on a simple calculation: 28 x 3.7 = 103.6Whrs i.e. above the regulation The reason why it is less than 98Whrs is that the battery actually drops down to around 3.5V during most of the useful discharge so the actual rating is 3.5 x 28 = 98WHrs. This subtlety will be lost on any airport security. Furthermore, they will be told to multiply the voltage by the amp-hours. As they will see 20V on the side, they may assume that the power rating is 560WHrs. This is not correct because the battery pack can only 20V through a boost conversion electronics which drop the current capacity. So moral of the story: Tape the rating part of the instructions which state 98Whrs to the side of the battery!! On the other parts: The battery pack is long and sleek. a little heavy, but perfectly fine. The cables are very tidy, and I really like the USB chargers build into the recharge unit. A very tidy piece of electronics. Most importantly, it should achieve 2 extra full charges for my surface pro laptop.

Owned for just short of a year and it occasionally started to smell slightly of overheating plastic whilst charging, but continued to work. It now smells strongly of overheating plastic within a short period of connecting the charger and will not charge. When it was working it worked well, which is why it has 2 and not 1 star.

Very good

While the product was ok for awhile, eventually it broke down and Qi-Infinity has not lived up to their agreement to replace the product, hassle free. The whole process has been full of hassles and I still have no replacement more than 2 months later....

Colis bien reçus dans les temps. ravis du produit qui marche pour le moment impeccablement une recharge rapide du téléphone que j'utilise comme outil de travail pour le boulot. Encombrant certes mais pratique; Il faut simplement que je teste à savoir le nombre de fois que je peux l'utliser pour la surface pro 3

I bought Qi-infinity to power my Surface laptop when travelling and I was initially very pleased even my usage has been really low due low amount of travelling in last months. Unfortunately, the product stopped working roughly 3 months of real usage with less than 20 recharges. Now the power pack doesn't start recharging devices when you try to put it on even if it's fully recharged. When I have the pack in the recharger, I can see the power being recharged but when you take it out, nothing happens when I push the power button. I have contacted customer service and waiting for repsonce.