Amazon.com: 14.4V 3200mAh i7 Battery Replacement for iRobot Roomba e and i Series, Large Capacity Battery Compatible with Roomba i7 i7+ i8 i6 i4 i4+ i3 i3+ i7158 J7 7150 7550 and
ABL-D1 Replacement Battery For iRobot Roomba Vacuum Cleaner e Series e5 e6 i Series i3 i4 i4+ i7 i7+ i8 7150 7550 e5150 e5152 - AliExpress
Here is the battery I got for my i7 the capacity says 2220 mah there was a video of the battery in the j7 and it was 2210 mah : r/roomba
How to Replace the Battery in the iRobot Roomba i7 / i7+ - YouTube
Amazon.com: 3200mAh i7 Lithium ion Replacement Battery for Irobot Roomba J7 J7+ i7 7150 i7+ 7550 e5 e5152 e5154 e6 i3 3150 i3+ 3550 i2 2152 i4 4150 i4+ i4 evo 4552 and e/i Series Vacuum-4624864, ABL-D1 -BURFLO : Home & Kitchen