# Double batteries? **URL:** \ **Category:** Mainboard\ **Created:** [February 14, 2024, 3:28pm UTC](https://community.frame.work/t/double-batteries/45300 "2024-02-14T15:28:27Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Fish](https://avatars.discourse-cdn.com/v4/letter/f/bc8723/32.png) [@Fish](https://community.frame.work/u/Fish)\ **Post date:** [February 14, 2024, 3:28pm UTC](https://community.frame.work/t/double-batteries/45300/1 "2024-02-14T15:28:27Z")
How difficult would it be to create a Y adapter that connects to the battery slot on the mainboard, and on the other end, has two slots for connecting two batteries? (Obviously, this would require a redesign of the mainframe.) Is such a design even feasible? ---
**Author:** ![Blake\_Galbraith](https://avatars.discourse-cdn.com/v4/letter/b/a698b9/32.png) [@Blake\_Galbraith](https://community.frame.work/u/Blake_Galbraith)\ **Post date:** [February 14, 2024, 7:48pm UTC](https://community.frame.work/t/double-batteries/45300/2 "2024-02-14T19:48:58Z")
The first thing to note here, is that it couldn’t be a straight Y adapter. The batteries would have to be connected in parallel so as not to exceed the voltage on the power input for the battery connector, someone feel free to correct me if I’m wrong here. I’m unsure how battery charging management would be handled, since you’d be charging what is essentially going to be a 110WH or 122WH battery, depending on which two batteries you connect together in this manner. This assumes the Framework 13. Sounds like a cool idea! ---
**Author:** ![Aaron\_Baff](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@Aaron\_Baff](https://community.frame.work/u/Aaron_Baff)\ **Post date:** [February 15, 2024, 12:55am UTC](https://community.frame.work/t/double-batteries/45300/3 "2024-02-15T00:55:21Z")
There’s also some communication between the EC and the battery, that’s how you get the battery %, etc in your OS. I think it’s using I2C, which can handle multiple endpoints on it, but you’d need to be sure that they’re at different addresses, which might not be the easiest. Plus, you’d need to change the chassis to be able to pass-through that wiring/connector. Better is the FW 16, which has some concept of 2nd/external battery via the interposer. Potentially even a underneath mounted battery slice, that the wiring goes up through the expansion slot to connect to the interposer. More complicated than just that, but conceptually it can be done. ---
**Author:** ![felurx](https://sea1.discourse-cdn.com/flex001/user_avatar/community.frame.work/felurx/32/18082_2.png) [@felurx](https://community.frame.work/u/felurx)\ **Post date:** [February 16, 2024, 12:33pm UTC](https://community.frame.work/t/double-batteries/45300/5 "2024-02-16T12:33:55Z")
I think this does sound kinda cool, but you’d probably be able to achieve pretty much all the same goals with a lot less complexity with a good USB-PD power bank ^^