# NHTSA Preliminary Evaluation PE14011
> **Bosch EV charging coupler overheating** · Opened 2014-04-15 · Closed 2014-11-21
## Investigation
- **Action number:** PE14011
- **Type:** Preliminary Evaluation
- **Open date:** 2014-04-15
- **Close date:** 2014-11-21
- **Manufacturer:** Robert Bosch, LLC
- **Affected makes:** BOSCH
- **Affected components:** ELECTRICAL SYSTEM; ELECTRICAL SYSTEM:12V/24V/48V BATTERY; ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY; HYBRID PROPULSION SYSTEM
- **Affected model years:** 9999
- **Affected (make, year) variants:** 4
## Summary

The Office of Defects Investigation (ODI) has received a total of 2 allegations of an overheated charging coupler on a Bosch Power Xpress 240V electric vehicle charger.According to the owners, the vehicles began to emit smoke after charging at home for over an hour and the charger coupler to the vehicle was hot to the touch.The overheating condition caused damage to the vehicle and charger, and in some cases, rendering both inoperable.One owner received a mild burn to his finger when attempting to detach the charger from the vehicle.The Bosch Power Xpress 240V charger is designed to recharge the battery of any electric vehicle using the standard, UL approved, Society of Automotive Engineers (SAE) J1772 charging coupler.The Bosch charger is hard wired at 240V into a home or business in a stationary installation and is capable of charging a vehicle at a rate of 16 to 32 amps.Testing conducted by Bosch indicates that the overheating condition in the coupler is caused by high electrical resistance in the metal charging pins encased within the J1772 coupler.The high resistance is the result of multiple factors including corrosion, wear on charging pins, charging pin plating materials, charging pin crimp connections and environmental conditions.All reported failures have occurred on vehicles charging at 30 amps with no indicated failures on chargers being operated at less than 30 amps.Throughout the production run of Power Xpress chargers, Bosch has used 3 different coupler designs with 2 different suppliers.However, there is no clear indication that one design is more failure prone than another.There have been no reported fires as a result of this issue.The coupler outer shell is made from a UL tested high temperature resistant material and all reported overheating events have been contained within the coupler.Bosch collects and maintains charger user records which indicate that out of over 6000 chargers sold, approximately 400 customers use the charger at 30 amps, and t

## Source
- [NHTSA ODI investigation page](https://www-odi.nhtsa.dot.gov/owners/SearchResults?searchType=ID&targetCategory=I&searchCriteria.nhtsa_ids=PE14011)
---
*AI Analytics · CC0 1.0*