Consider replacing the tool unless you find NOS (new old stock) parts via eBay or surplus tool suppliers.
Appendix with technical specifications: Battery type, weight, dimensions, operating temperature range. Also, contact info for customer support in case users have questions. Air Precision Elt 96 Maintenance Manual
To the untrained eye, it was a grimy yellow box, about the size of a lunch pail, battered and smelling of stale ozone. To the procurement office, it was surplus inventory scheduled for incineration. But to Elias, it was a period piece, a relic from the golden era of "over-engineering." Consider replacing the tool unless you find NOS
: Batteries must be replaced by the expiration date indicated on the unit's exterior label. Periodic Inspections operating temperature range. Also