Battery, ZeroLemon Slim Juice 3500mAh External Battery Backup with Cords for Google Nexus 5 & G2 [180 Days ZeroLemon Warranty Guarantee]-Black

The battery itself seems to work well. No problems using it to power/charge the phoneCaveat 1: Does not come with 'U Shape' connector and neither does the case, so don't buy the case and battery separately, even in the same order. You can't get one, even from the seller. They only come in the full kit, which is apparently not for sale anywhere.Caveat 2: It charges your internal battery first and even good chargers may not have the juice to charge both batteries at the same time. I left it overnight on a 2.1A charger and the external battery didn't charge at all with the phone on. I have to charge both batteries separately to get the charge cycle down to a reasonable time frame.

Purchased battery and case. The battery WAS the correct custom fit battery made for the case. Was missing the small black "u shaped cable" to power the phone. When confronted they tried to convince me that the battery I purchased was not the custom fit battery that zero lemon made to fit that case and that even if I had the little u shaped cable it would not fit. I tested this with my friends u shaped cable and it worked properly. Very bad seller. The repeatedly lied to me and thought I should buy it.