Dell latitude e5440

Welcome to the Dell Community @Elizabethlynnsmith 

I just checked a few of the E5440's and none have the connector in the media bay for a second battery.

So it must be the connector on the base that is used.

That would mean it is a "Slice" and or "Extended" battery.

This is the only one I could find at the Parts People.

Dell OEM 97Wh Latitude E6520 E6420 E6220 E6320 9-cell Original Laptop Extended Battery Slice - KJ321:

https://www.parts-people.com/index.php?action=item&id=16547

You can check for compatibility there.

Best regards,

U2

@Elizabethlynnsmith 

I would take a shot at buying a brand new Dell OEM battery for $25 with the caveat that batteries life decrease even when they are sitting on a shelf.

https://www.ebay.com/itm/NEW-OEM-GENUINE-Dell-Latitude-BATTERY-E6400-E6410-E6500-E6510-KY477-PT434-W1193/332801696650

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