Hi,
Just discharge at a maximum of 80 Amps ( 4000ma = 4 Amp x 20 ). Charge at about 4 Amps for longevity ( 4000ma = 4 Amp's ).
Don't worry about it being made in China, as practically everything is nowadays, even the Girl I slept with last year. Lol.
This junk is made in China, and it's proving OK;
