Notes by Akhil Saji


DJI Care Refresh Experience

I recently became the proud owner of a DJI Spark drone with lofty goal of learning how to take great aerial photographs. For those of you who may be unfamiliar with DJI, they are the foremost maker of consumer and prosumer drones. They have a lineup of models ranging from the relatively inexpensive Spark to the filmmaker oriented Inspire series. All of their models come with an extended warranty service called DJI Care Refresh which covers water damage, crash damage and almost any kind of accidental damage possible. See here for details. The caveat for purchasing this coverage is that you only have 48h from when your drone is activated to make the purchase.

Initially hesitant to shell out an additional $59, my logical senses kicked in and I made the purchase for the coverage hoping to never have to use it. Well, about a week into ownership on my fourth flight, I ended up crashing the drone into a tree while attempting to land near a lake. My drone both hit the tree and fell into a shallow pool of water in the process. Suffice to say, my Spark would not even power on after that. I immediately went home and used the dji repair website to file my claim and shipped my drone out the same day (5/7). The service center is in California so it took about 4 days for it to arrive from New York (5/11). On 5/14 the service center tagged my drone as arrived and by 5/15 my replacement drone was shipped out. Much to my surprise, they even shipped the replacement using UPS 2 Day Air which enabled me to receive it by 5/17. DJI even called me on 5/17 to make sure I had received my drone and I was happy with the refresh service.

As you can see my experience with the Care Refresh service was excellent and I really appreciated the fast turn-around time. I would highly suggest purchasing this service with your drone unless you are extremely confident in your flying abilities.

My Zotero Sync Setup

Zotero is a free cross-platform research (journal articles, web pages, etc.) management tool. Click here to learn more if you're unfamiliar with how it works.

Zotero comes with a built-in file sync function which enables users to sync their Zotero libraries across platforms (such as iOS, android, Windows, etc.). Unfortunately, their "free" tier of sync service has a limit of 300Mb which can quickly get filled up if you archive lots of papers like myself. Lucky for us, Zotero comes with WebDAV support which can be utilized in place of their storage service. Most people including myself don't have a personal webDAV server; however, has a free tier of service with 5Gb of space that includes WebDAV support. Below are my sample settings to show you how to set this up for yourself.

  1. First navigate to the preferences menu and select the sync tab.
  2. Under the "Zotero Sync Server" section, enter your Zotero sync service username and password. Check off "sync full-context"
  3. Under "File Syncing" ensure that you check off the box for "Sync attachment files in My Library using" then select WebDAV.
  4. In the same section, for url select https:// from the dropdown and enter in the adjacent textbox.
  5. Finally, in the same section enter your username and password.
  6. Click verify server to ensure the box sync is properly working. Assuming all goes well, you'll now be able to store 5Gb of content for free.

iPhone 6 battery replacement experience


Recently, I have been following the apple battery throttling scandal that started with a Reddit post and subsequently a formal analysis by GeekBench author John Poole which led me to wonder if the poor performance I've experienced on my iPhone 6 since last year could be related to it. My iPhone 6 was purchased in December 2014 and has been my workhorse for over three years. I never felt the need to upgrade until recently due to it offering all the features I use on a daily basis including Apple Pay, a decent camera, and common tasks such as email and messages. Not much has changed regarding features that I desire; however, one critical thing that began to bother me and compel me to upgrade was the consistent lag on the device. Once seamless tasks such as opening Mail or responding to multiple message chains on Messages while browsing the web slowed to a crawl within the past six months.

Fast forward to the December 2017 revelation of what some on Twitter are calling #ThrottleGate which subsequently led to Apple issuing a formal response; I decided to take matters into my own hands. I had already replaced the screen on my device earlier in 2017 due to an accidental fall out of my pocket, and therefore, I wouldn't be eligible for the discounted $29 apple battery replacement. I went for the next best option. After some research on Reddit and various other internet sources, seemed to have a reputation for offering close to OEM standard battery replacements for iPhones.

Pre-Replacement Capacity and Benchmark

The battery I ordered was delivered within seven days, and I began the process of preparing to replace it. My first step was to analyze data from the original Apple battery using a free tool called coconutBattery. The results (screenshot below) showed that my battery could only deliver roughly 85.3% of its original design capacity and has over 1100 charge cycles recorded. The second step I took was to run the iOS Geekbench CPU benchmark to confirm my suspicions on whether or not my device's CPU (Apple A8) was in-fact being throttled. The results (screenshot below) showed a single core score of 1315 and a multi-core score of 2235.

coconutbattery-preinstall geekbench-preinstall

Post-Replacement Capacity and Benchmark

Using the iFixIt guide I was able to replace the battery within roughly an hour. I found the most difficult part of the repair to be aligning the new battery connector likec the OEM battery. The replacement battery comes in an "unfolded" state and therefore, I would suggest prior to placing the battery onto the adhesive in the case, manipulating the battery cable into a folded state similar to the OEM battery- this will make your installation easier. After the phone booted up, I re-ran the Geekbench iOS benchmark and tested the battery using coconutBattery as I did prior. The geekbench results showed a single core score of 1498 (~13.9% improvement) and a multi-core score of 2606 (~16.5% improvement).

coconutbattery-postinstall geekbench-postinstall


After two days of continuous use of the iPhone 6 with the new battery, I am happy to report that my phone is back to the level of operating performance I experienced when I originally purchased the phone. I no longer experience stuttering or user interface latency when I am multitasking or even doing simple tasks such as responding to text messages. If you have an iPhone 6S or below and are considering purchasing a new phone due to lag, I would highly suggest investigating the state of your battery before doing so. It may save you a few dollars and allow you to hold out a bit longer before upgrading.