---
title: "Tesla BMS_u029 / BMS_f107 Battery Fault: Repair Cost | EV Fix Guide"
description: "'Maximum battery charge level reduced' or 'Vehicle cannot drive / charge' high-voltage safety alert. Tesla Service: $13,000 - $20,000. Independent: $1,800 - $3,500. Why it is not DIY and where to get it fixed."
canonical: https://evfixguide.com/guides/bms-u029-battery-isolation
lang: en
last_updated: 2026-10-24
---

[Tesla Model 3](https://evfixguide.com/models/model-3) · [Tesla Model Y](https://evfixguide.com/models/model-y) · [Tesla Model S](https://evfixguide.com/models/model-s) · [Tesla Model X](https://evfixguide.com/models/model-x) Battery & Charging Professional repair only

# Tesla BMS_u029 / BMS_f107 Battery Fault: Repair Cost

By the EV Fix Guide editorial team · Updated October 24, 2026 · [How we estimate costs](https://evfixguide.com/about#how-we-estimate-costs)

## Quick answer

'Maximum battery charge level reduced' or 'Vehicle cannot drive / charge' high-voltage safety alert. At a Tesla Service Center this typically costs **$13,000 - $20,000 (Complete pack replacement)**. An independent shop charges about **$1,800 - $3,500 (Module repair & BMS rebalance)** — potential savings of **75% - 85%**. **Do not attempt this at home.**

![BMS_u029 / BMS_f107 High-Voltage Battery Isolation Fault](https://evfixguide.com/assets/images/battery-bench.jpg)

## Symptoms

- 'BMS_u029: Maximum charge level and range may be reduced' alert on touchscreen
- DC Fast Charging (Supercharging) completely disabled
- Abrupt reduction in available vehicle range by 30% to 50%

## Repair cost: Tesla vs independent shop vs DIY

| Option | Typical cost (USD) |
| --- | --- |
| Tesla Service Center | $13,000 - $20,000 (Complete pack replacement) |
| Independent shop | $1,800 - $3,500 (Module repair & BMS rebalance) |
| DIY | Not possible at home (Lethal safety risk) |
| Potential savings | 75% - 85% |

Ranges are US estimates compiled from owner reports and shop quotes; prices vary by region, model year and parts availability. Report your price.

## Can an independent shop fix it?

CAN BE REPAIRED AT INDEPENDENT EV BATTERY LABS. While Tesla demands $13,000-$20,000 for a whole new pack, independent specialists drop the pack, replace only the single degraded module or pyro-fuse, and rebalance all cells to <4mV tolerance.

[Get matched with an independent shop →](https://evfixguide.com/?shop=bms-u029-battery-isolation#find-shop-section)

## How professionals repair it

**Safety warning:** 400V High-Voltage carries lethal electrocution risks. Must only be handled in an isolated cleanroom laboratory by certified EV technicians.

### Tools a shop uses

- 1000V Insulated HV Safety Gloves & Tools
- Hydraulic Battery Lift Table
- Tesla Toolbox & High-Precision Module Balancing Charger

### Steps

1. Hoist the vehicle, disconnect the 12V system and open the HV pyro-fuse safety interlock.
2. Drop the high-voltage battery pack using a dedicated hydraulic lift table by removing the 32 perimeter bolts.
3. Open the top enclosure seal and use thermal imaging / CAN telemetry to identify the imbalanced module brick.
4. Swap out the degraded module for a health-matched module with identical internal resistance and capacity.
5. Perform precision balancing across all series cell bricks, apply fresh gasket sealant, and remount the pack.

**Pro tip:** Tesla Service will state the battery is non-serviceable and force full replacement. Globally and locally, certified independent EV battery labs repair these modules with surgical precision for a fraction of the cost.

## Deep dives

- [BMS_u029 deep dive: root cause & module repair →](https://evfixguide.com/repairs/bms-u029)
- [BMS_f107 deep dive: isolation fault diagnosis →](https://evfixguide.com/repairs/bms-f107)
- [Model S battery replacement cost: Tesla vs independent →](https://evfixguide.com/repairs/tesla-model-s-battery-replacement)

## Frequently asked questions

### How much does it cost to fix a BMS_u029 or BMS_f107 battery fault on a Tesla?

Tesla Service Center: $13,000 - $20,000 (Complete pack replacement). Independent shop: $1,800 - $3,500 (Module repair & BMS rebalance). DIY: Not possible at home (Lethal safety risk). Typical savings versus the service center: 75% - 85%.

### Can I fix a BMS_u029 or BMS_f107 battery fault myself?

No, this is not a safe DIY job. 400V High-Voltage carries lethal electrocution risks. Must only be handled in an isolated cleanroom laboratory by certified EV technicians.

### Can an independent shop fix a BMS_u029 or BMS_f107 battery fault instead of Tesla?

Yes. CAN BE REPAIRED AT INDEPENDENT EV BATTERY LABS. While Tesla demands $13,000-$20,000 for a whole new pack, independent specialists drop the pack, replace only the single degraded module or pyro-fuse, and rebalance all cells to <4mV tolerance.

### Which Tesla models are affected by a BMS_u029 or BMS_f107 battery fault?

This issue is reported on the Tesla Model S, Model X, Model 3 and Model Y.

## Related guides

- [Tesla 12V / 16V Battery Replacement: Cost & DIY Guide — Independent: $100 - $150](https://evfixguide.com/guides/12v-16v-low-voltage-battery)
- [Tesla Charge Port Door Stuck or Won’t Open: Fix & Cost — Independent: $120 - $200](https://evfixguide.com/guides/charge-port-door-stuck)
- [Tesla Pyrofuse Failure: Symptoms & Replacement Cost — Independent: $190 - $320](https://evfixguide.com/guides/pyrofuse-high-voltage-fuse)
- [Tesla Frunk Won’t Open (Dead 12V): Model 3/Y Fix — Independent: $50 - $150](https://evfixguide.com/guides/frunk-dead-12v-battery)
- [Tesla VCFRONT_a180: Electrical System Power Reduced Fix — Independent: $100 - $300](https://evfixguide.com/guides/vcfront-a180-electrical-power-reduced)
- [Tesla VCFRONT_a182: Replace Low Voltage Battery (Cost) — Independent: $100 - $250](https://evfixguide.com/guides/vcfront-a182-replace-low-voltage-battery)

This guide is for information only. High-voltage components (orange cables) can be lethal — leave them to trained technicians. Not affiliated with Tesla, Inc.