I ran my G5's battery down to 25% today and wanted to see how fast the fast charger was charging, so I plugged the phone into the LG charger with the LG cable and started a stop watch. I came back 15 minutes later to look at the battery level and it had only gained about 10% and it said it would take over 2 hours to charge it to 100%. I checked several more times and after 50 minutes, it had only gained 23%. It said it was fast charging, but it wasn't charging any faster than my other phones would.
Now I know I had seen it charge faster that that, but previously I had used some cables from Amazon. So I swapped the cable out with a 6 foot one I got from Amazon and all of a suddenly it was charging fast. In the next 10 minutes it gained another 18%.
Here's a picture of the battery graph showing the first 50 minutes of charging with the LG cable and then the next 10 minutes with the cable from Amazon.
Now I know I had seen it charge faster that that, but previously I had used some cables from Amazon. So I swapped the cable out with a 6 foot one I got from Amazon and all of a suddenly it was charging fast. In the next 10 minutes it gained another 18%.
Here's a picture of the battery graph showing the first 50 minutes of charging with the LG cable and then the next 10 minutes with the cable from Amazon.