Well, it's ok, but not great. It charges 4 standard AA Eneloops faster than ZMI's charger. 4.5 hours instead of 8 hours. AAs do heat up at the end. Plastic of the body has a noticeable smell. When using it as a powerbank, it starts producing a high-pitched noise after some time. So in general, it's not perfect but better than other portable chargers in terms of charging speed. It's the only option if you need AA charger to carry on you back when hiking or in bicycle bags. I don't think the powerbank function is something necessary, but rather a function that allows you to discharge your NiMh batteries before charging them. PS. This shop didn't want to change delivery address using messages. So I had to cancel my order and make a new one. As a result I lost one coupon and it costed my 1$ more than the first order.
I dont know why but it cant charge all my batteries... With aa all good. But with my aaa charger didn't work... At all great form factor . The seller works great and have fast shipping.