Research Report · February 2026

State of Tesla Battery
Health 2026

Basierend auf 259 realen Analysen aus der Werkstatt von RPR Motors / Tesla Battery Experts

Real data. No PR spin. Based on 259 battery analyses across 23 unique vehicles — from a working workshop floor, not a lab. Every number in this report comes directly from BattCheck diagnostic logs processed through our SoHWHAT analysis engine.

📍 RPR Motors / Tesla Battery Experts · Kelberg am Nürburgring, Germany · battcheck.eu · sohwhat.com

259
Battery Analyses
23
Unique Vehicles
89.1%
Average SOH
79.2
Avg THS Score / 100
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Executive Summary

Between 2024 and early 2026, the workshop at RPR Motors / Tesla Battery Experts ran 259 individual BattCheck diagnostic sessions across 23 unique Tesla vehicles. This report presents the findings — unfiltered, statistically significant, and directly actionable.

✅ The Good News

The average fleet State of Health is 89.1%. Vehicles at 200,000+ km still maintain an average SOH of 86.8% — a remarkable result for real-world electric vehicles with heavy use. The 100 kWh Model S/X packs average 95.3% SOH, proving that NCA chemistry ages exceptionally well.

⚠️ The Problem

Our Giga Berlin Model Y data comes primarily from a high-mileage taxi (218,000+ km) — extreme usage, not typical ownership. A second Berlin taxi arrives soon for comparison. Early indicatform in our dataset. Average SOH: 70.2%. Meanwhile, moisture ingress in Model S packs is widespread — 37 analyses show Critical or High water levels. These aren't edge cases. They're patterns.

🔴 Headline finding: LG Berlin cells (Model Y Giga Berlin, 2022+) average 70.2% SOH — a full 21 percentage points below the LG 2170L (non-Berlin) pack average of 91.3%. This difference is striking, but driven by extreme commercial use (taxi fleet with 218k+ km). More data needed before drawing broad conclusions. It remains a notable variance in our dataset.
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Fleet Overview

SOH distribution across all 259 analyses. LFP packs (CATL) excluded from histogram — BMS calibration artifacts produce readings above 100%.

SOH Distribution

<60%
3
60-69%
28
70-79%
8
80-89%
29
90-94%
134
95-100%
51

📊 Most vehicles cluster in the 90–94% SOH range (134 of 253 vehicles with SOH ≤ 100%). The long tail below 70% comes from a high-mileage Berlin taxi (218k+ km) — not typical consumer use.

SOH by Pack

Pack N Avg SOH Min Max
LG 2170L 78.8kWh 77 91.3% 72.1% 92.3%
Model S/X 100 kWh Pack (HW-ID 79) 64 95.3% 91.5% 99.9%
LG Berlin 78.8kWh 31 70.2% 66.1% 96.6%
Model S/X 75 kWh Pack (HW-ID 41) 24 89.8% 76.5% 91.1%
Model S/X 85 kWh Pack (HW-ID 81) 12 93.5% 85.2% 97.5%
LG 2170C 75kWh 11 96.7% 96.2% 96.9%
Model S/X 85 kWh Pack (400V, 16 Module, HW-ID 24) 6 92.8% 92.8% 92.8%
Model S/X 85 kWh Pack (HW-ID 71) 5 85.1% 82.8% 88.5%
Model S/X 60 kWh Pack (350V, 14 Module, HW-ID 39) 5 87.5% 87.5% 87.5%
Panasonic Performance 78.8kWh 4 74.0% 74.0% 74.0%
Model S/X 70 kWh Pack (HW-ID 65) 4 85.5% 85.5% 85.5%
Panasonic LR 78.8kWh 3 87.4% 87.4% 87.4%
Model S/X 85 kWh Pack (400V, 16 Module, HW-ID 82) 3 85.4% 85.4% 85.4%
Model S/X 75 kWh Pack (350V, 14 Module, HW-ID 80) 3 54.4% 54.4% 54.4%
Model S/X 60 kWh Pack (HW-ID 39) 1 87.5% 87.5% 87.5%

🔴 Red row = LG Berlin 78.8 kWh (Giga Berlin). CATL LFP packs omitted (BMS calibration shows >100%).

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🔴 The LG Berlin Finding

Model Y vehicles built at Giga Berlin (factory code XP7) with LG 2170 cells are showing a degradation pattern that stands out sharply from the rest of our dataset. After analysing 31 sessions across these vehicles, the numbers tell a clear story.

70.2%
Average State of Health — LG Berlin 78.8 kWh
66.1%
Worst case SOH
96.6%
Best case SOH
31
Analyses

Why Does This Matter?

A 70.2% average SOH means these vehicles have lost roughly 23.5 kWh of usable capacity from a 78.8 kWh pack. Real-world range impact: 150–200 km less than rated on a full charge.

For comparison, LG 2170L packs (non-Berlin) average 91.3% SOH — a 21 percentage point gap for packs with the same nominal capacity.

What We Think Is Happening

The LG 2170 cells in this Giga Berlin taxi show significant capacity fade at 218k+ km. Whether this reflects cell chemistry, extreme commercial use, or charging patterns is not yet clenditions. Early production vehicles (2022 build dates) show the most pronounced degradation.

The best-case Berlin reading of 96.6% suggests not all Berlin cells degrade equally — usage pattern and charging behaviour play a role.

💡 Bottom line: If you own or are buying a used Giga Berlin Model Y — especially ex-taxi or high-mileage — a SoHWHAT analysis before purchase is strongly recommended. The degradation range (66.1%–96.6% SOH) is extremely wide — you need to know which end of that range you're on.
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Moisture: The Silent Killer

Water inside a high-voltage battery pack is one of the most underdiagnosed risks in used Tesla ownership. BattCheck measures moisture via conductivity sensors inside the pack. The results in our Model S/X dataset are sobering.

37
Critical moisture
⚠️ Immediate action
4
High moisture
📋 Service recommended
15
Elevated moisture
👀 Monitor closely
73
Normal / Good
✅ No action needed
Critical
37 (28.7%)
High
4 (3.1%)
Elevated
15 (11.6%)
Normal / Good
73 (56.6%)

How Does Water Get In?

Model S packs have two known moisture entry points:

  • Blech-Sicherungsdeckel (sheet metal fuse cover) — corrodes over time, allows water ingress at the high-voltage junction
  • Umbrella Valves — pressure equalisation valves that fail and allow moisture entry, especially in older packs

These are design-related issues, not abuse-related. Any Model S built before 2019 should be checked.

What Happens If Ignored?

Moisture causes corrosion of cell contacts and bus bars, degraded isolation resistance, BMS fault codes, and in severe cases — thermal events. A critical moisture reading means the pack needs service now, not at the next convenience.

Our CNC-machined replacement cover eliminates the Blech-Sicherungsdeckel failure mode permanently.

From the Workshop Floor

Severely corroded Blech-Sicherungsdeckel on Tesla Model S pack
🔧 Corroded Blech-Sicherungsdeckel from a Model S with critical moisture reading (196g water content measured). This is a stock cover that failed due to condensation cycling.
Before and after: OEM cover vs CNC-machined replacement
⚙️ Before/after: OEM corroded cover (top) vs our CNC-machined stainless replacement. The upgraded cover provides a permanent seal and eliminates this moisture path.

Real Certificate Examples

Anonymised SoHWHAT certificates from actual customer vehicles. These show what a moisture reading looks like in the official report.

BattCheck certificate showing 115g moisture content
115g measured moisture — "High" category. Service recommended.
BattCheck certificate showing 196g moisture content
196g measured moisture — "Critical" category. Immediate action required.
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Mileage vs. Degradation

Do Teslas degrade linearly with mileage? Our data says: not quite. The biggest drop happens early. High-mileage vehicles hold up better than most people expect.

📊 Key finding: At 200,000+ km, the average SOH in our dataset is still 86.8%. That's only ~12% capacity loss after 200k km of real-world driving.
Mileage Bracket Vehicles Avg SOH Avg Degradation
<50k km 7 97.5% 2.5%
50-100k km 37 99.0% 1.0%
100-150k km 23 89.9% 10.1%
150-200k km 2 87.4% 12.6%
>200k km 175 86.8% 13.2%

The Early Degradation Curve

New-vehicle SOH averaging 97.5% at under 50k km is expected — early lithium-ion degradation is steepest in the first charging cycles. By 100k km the curve flattens significantly, which is why many high-mileage Tesla owners report stable range year over year.

What "Degradation %" Means

The degradation_percent field represents capacity lost relative to the original factory specification. A 13.2% average degradation at 200k+ km means a 78.8 kWh pack has roughly 68.4 kWh of usable capacity remaining — still very practical for most use cases.

⚠️ Mileage brackets are skewed by a high-mileage Berlin taxi in the >200k group. Separating by pack chemistry would give a cleaner picture — this is an area for future analysis as the dataset grows.

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THS Score Distribution

The Tesla Health Score (THS) is SoHWHAT's composite metric — combining SOH, cell balance, isolation, moisture, BMS errors, and charge efficiency into a single 0–100 number. It gives a more complete picture than SOH alone.

79.2
Fleet Average THS
29
Lowest Recorded THS
100
Highest Recorded THS
🟢 Excellent (90-100)
83 (44.9%)
🟡 Good (70-89)
54 (29.2%)
🟠 Fair (50-69)
17 (9.2%)
🔴 Poor (<50)
31 (16.8%)

What a High THS Means

A THS of 90–100 indicates a battery that's performing close to new — excellent capacity, tight cell balance, clean isolation, dry pack, no BMS faults. 83 vehicles in our dataset hit this range.

What a Low THS Means

THS below 50 signals multiple simultaneous health concerns — typically a combination of low SOH, high cell imbalance, and moisture or isolation issues. 31 vehicles fall in this range and need immediate assessment.

7

Brick-Level Insights

BattCheck captures data at the individual brick (module group) level — including per-brick charge capacity (CAC) and voltage. This allows us to identify imbalances that a simple SOH measurement would miss entirely.

Worst CAC Spreads

CAC spread = max brick capacity minus min brick capacity (in Amp-hours). High spread = severe cell imbalance, often causing premature BMS cutoffs.

VIN CAC Spread SOH Pack
***101350 129.0 Ah 85.5% 70 kWh (HW-ID 65)
***P47336 103.0 Ah 87.5% 60 kWh (HW-ID 39)
***071381 56.0 Ah 66.1% LG Berlin 78.8kWh
***412681 27.1 Ah 72.1% LG 2170L 78.8kWh

Worst Cell Imbalances

Cell imbalance measured in millivolts (mV) between highest and lowest brick voltage. Above 50 mV is concerning; above 200 mV is critical.

VIN Imbalance SOH Severity
***186628 627.2 mV 54.4% 🔴 Critical
***412681 359.6 mV 92.2% 🟠 High
***071381 249.6 mV 66.1% 🟠 High
***412681 191.2 mV 92.2% 🟡 Elevated
***071381 164.4 mV 66.1% 🟡 Elevated

⚡ Why CAC Spread Matters More Than SOH

A vehicle can show a "decent" SOH of 85% while having a CAC spread of 100+ Ah between its weakest and strongest brick. In practice, the BMS caps charging and discharging to protect the weakest brick — meaning you lose usable range far beyond what SOH alone suggests. The 627 mV imbalance case above (SOH: 54.4%) is a pack in urgent need of servicing.

8

Chemistry Comparison

Tesla has used multiple cell chemistries across its product line. Our dataset covers NCA (Panasonic, used in Model S/X), NMC/LG 2170 (Model 3/Y), and LFP (CATL, Standard Range). Here's how they compare on real-world degradation.

NCA (Panasonic) Model S/X 85–100 kWh
93.4%
avg SOH
Proven long-term durability. 100 kWh packs average 95.3% SOH.
NMC / LG 2170L Model 3/Y (non-Berlin)
91.3%
avg SOH
Solid performance. Most packs still above 90% even with heavy use.
LG 2170 Berlin Model Y (Giga Berlin, 2022+)
70.2%
avg SOH
⚠️ Significantly lower average SOH. Fastest degradation observed in dataset.
CATL LFP Model 3/Y Standard Range
~93 (calibrated)
avg SOH
LFP cells show >100% BMS readings (calibration artifact). Real capacity stable.
Panasonic (Perf/LR) Model 3/Y Long Range, Performance
80.7%
avg SOH
Early 2170 cells (pre-2022). Moderate degradation, limited sample.
⚠️ Note on LFP readings: CATL LFP packs often show SOH above 100% in BattCheck data — this is a known BMS calibration artefact, not a real capacity gain. LFP chemistry is inherently stable but requires a different interpretation methodology. We're working on LFP-specific calibration for future reports.
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Key Takeaways

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About SoHWHAT

SoHWHAT

Know Your Battery. Really Know It.

SoHWHAT is the battery intelligence platform behind every analysis in this report. We turn raw BattCheck diagnostic data into professional certificates, workshop reports, and buyer protection documents — for workshops, dealers, and individual owners.

📜 Battery Health Certificate from €99
Get Your Certificate Workshop: BattCheck.eu

250+
Batteries Repaired
259
Diagnostic Sessions
2013–2025
Model Years Covered
Methodology note: All data in this report comes directly from BattCheck diagnostic sessions processed by the SoHWHAT engine. Analyses represent multiple sessions per vehicle in some cases (repeated scans over time). VINs anonymised to last 6 characters. Report generated: 20 February 2026. Data current as of February 2026.