EL
ErrorLib
Brands
||
  1. Home
  2. Fronius
  3. Perfect Charging
  4. 29
About·Privacy·Terms

ErrorLib — Industrial Fault Code Library

Disclaimer: ErrorLib is an independent technical reference tool. While we aim for accuracy, always verify with the manufacturer’s official service manuals before performing maintenance on industrial equipment. ErrorLib is not affiliated with the brands listed.

29

Incorrect Battery Polarity

Fronius · Perfect Charging

What does 29 mean?

The connected battery has been connected with reverse polarity to the charger. This is a critical fault that can cause severe and immediate damage to both the battery and the charger's power electronics if current is allowed to flow.

Common Causes

  • The battery cables have been physically connected to the charger terminals in reverse (positive to negative, negative to positive).
  • Incorrect wiring of the battery pack itself or its external connections.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    IMMEDIATELY disconnect the battery from the charger to prevent further damage.

  2. 2

    Visually inspect and verify that the positive (+) terminal of the battery is connected to the positive (+) terminal of the charger, and the negative (-) terminal of the battery is connected to the negative (-) terminal of the charger.

  3. 3

    After correcting the polarity, inspect both the charger and the battery terminals for any signs of damage (e.g., burning, melting) that may have occurred.

Browse all codes in this manual (61)
Verified technical data. Last updated: April 2026

Related Faults

101Gateway CAN Connect Timeout102Gateway No Back-end Connection103Gateway Charger/Registration Mismatch
Source: Fronius Perfect Charging
Open Manual (Page 50)Search more codes in this manual