Bests & Worsts Reviews from Amazon

I'm a design engineer and have designed numerous circuits much more complex than this. The device has at least two serious design flaws - (a) It's internal timer shuts off the laptop charging output after a few minutes after the first time it is connected; I had to restart the charger, and (b) This 23000mAH fully charged unit sank to near-zero charge after it charged my 5100mAH Lenovo laptop battery to barely 35% -- charging efficiency is ridiculously low! Also, Lenovo laptops are usually spec'd at 20V input whereas this charger is spec'd at 19V. This will also contribute to problems like the above. I would not recommend this for laptops that use higher voltages than 12V because of the (b) symptom. Sending it back to Amazon. ******** UPDATE May 16, 2014: OPEN BRIBING BY COMPANY ********** I received an email from the supplier today, relevant parts copied below: "... we would like to send you an adjustable tripod stand as compensation. Here is the link for your reference: http://www.amazon.com/Aibocn-Octopus-Adjustable-Blackberry-Smartphone/dp/B00E19VM08/ref=sr_1_9?ie=UTF8&qid=1393932361&sr=8-9&keywords=aibocn. Would you like to accept this offer and kindly help to remove your previous feedback? " It is disturbing how ethical values have dipped where companies are openly offering bribes to customers. Based on this, I am downgrading their rating from 2 stars to 1.