Chuwi has official forums [Google English]. Registration is required to access all content in posts. Note that, at least in my case using Firefox, I couldn’t register or log in using Google Translate. I had to log into the native Chinese site to see everything in posts (like embedded photos) and keep a separate Google Translate tab open to understand the text.
Google English: Chuwi V88 April 25th firmware download — note that a user says the installer is infected with a virus. There also seems to be two versions of this firmware and the Google Translate is too ambiguous to decipher.
Even though the battery in the Chuwi V88 says it’s 4270mAh, Chuwi has its engineers explain — through math I don’t understand — how it’s actually 5000mAh worth of electricity as used by the device [Google English]: Chi is the official Detailed V88 battery capacity of 5000 mA. If I understand the Google Translate correctly, the battery is also sourced from Samsung.