LEVC TX battery degradation: when is the right time to sell?

The LEVC TX is range-extended electric: the lithium-ion traction battery (31 kWh nominal, with a usable capacity of around 27 kWh in real-world service) drives the wheels exclusively, and the 1.5 litre petrol generator (a 78 kW unit from Volvo, since LEVC is owned by Geely) tops up the battery when needed. This drivetrain is more forgiving to the battery than a pure-EV setup for two specific reasons.

First, the depth-of-discharge cycle is shallower. A pure EV cab on a long shift cycles the battery from 90 per cent down to 20 per cent and back; the TX typically cycles in the 40 to 80 per cent band because the range-extender kicks in around 30 per cent state-of-charge and tops up to roughly 80 per cent before disengaging. Shallow cycles age lithium cells more slowly than deep cycles, regardless of total energy throughput.

Second, the average operating temperature is lower. A pure EV at depot DC fast-charging cycles the battery through significant thermal events; the TX charges slowly overnight via a 7 kW domestic-grade charger or, in some cases, just runs from the range-extender all shift. Lower thermal stress over the years extends pack life materially.

The practical effect of these two factors is that 2018 to 2020 build TX cabs at 200,000+ miles are commonly showing state-of-health figures in the 78 to 88 per cent band in 2026, which is materially better than equivalent-mileage pure-EV cabs of the same vintage.

State-of-health (SOH) is the ratio of current battery capacity to original new capacity, expressed as a percentage. A pack at 80 per cent SOH has 80 per cent of the energy it had when new; the remaining 20 per cent has been lost to chemical aging.

On a TX, the SOH reading you get from the LEVC dealer diagnostic tool is the cell-balanced capacity figure averaged across all 96 cells in the pack. It does not tell you about individual cell drift; for that you need the full cell-balance report, which a dealer can run as an additional diagnostic. Drift is more important than headline SOH for predicting future failure: a pack at 85 per cent SOH with all cells within 50 mV of each other is healthy and will continue to age slowly; a pack at 88 per cent SOH with two cells 200 mV adrift is at much higher risk of a fault in the next 12 months.

If you are selling, the buyer will want the SOH headline number plus, ideally, the cell-balance report. A clean cell-balance reading is worth real money on resale because it gives the buyer confidence about the next 12 to 24 months of operation. An SOH-only reading is fine but slightly less informative; the buyer prices a small risk premium.

Trade data from 2018 to 2024 builds gives a reasonable picture of how the pack ages in active London Hackney service:

• Years 1 to 3 (typically 0 to 80,000 miles): rapid initial loss of roughly 4 to 6 per cent SOH as the pack settles into its equilibrium chemistry. By the end of year 3, most cabs are at 94 to 96 per cent SOH.
• Years 3 to 6 (typically 80,000 to 180,000 miles): slow steady decline of roughly 1.5 to 2 per cent SOH per year. By the end of year 6, most cabs are at 86 to 90 per cent SOH.
• Years 6 to 9 (typically 180,000 to 280,000 miles): decline accelerates slightly to roughly 2 to 3 per cent per year. By the end of year 9, most cabs are at 78 to 84 per cent SOH.
• Year 9+ (typically 280,000+ miles): the curve becomes less predictable. Some packs stay stable through to year 12; others enter accelerated degradation at 1 to 2 cells dropping faster than the rest of the pack, which can push usable range down sharply over a few months.

There is no single SOH threshold that defines the right time. The right time depends on the rate of recent change in SOH, the cell-balance picture, the remaining plate validity, and your operational tolerance for the range-extender doing more of the work as the battery contributes less.

A useful rule of thumb: if your SOH has dropped more than 4 percentage points in the past 12 months (verified with two readings 12 months apart), the pack is in the accelerated-degradation phase and the next 12 months are likely to see further sharp drops. That is a strong sell signal regardless of the absolute SOH number, because the resale buyer is pricing forward risk and that forward risk just stepped up.

Conversely, an SOH of 80 per cent that has dropped only 1.5 percentage points in the past 12 months is in the steady-state phase and you can run the cab for another 24 months with reasonable confidence about pack behaviour. Selling at that point is a plate-validity + financial-position decision, not a battery decision.

The trade does price SOH but not as aggressively as drivers often expect. A clean 2020 LEVC TX with 130,000 miles trades in the £25,000 to £32,000 band in 2026 depending on plate validity, body condition, and trim. SOH at 90 per cent versus 84 per cent on the same vehicle typically moves the price by £1,200 to £2,000, not £4,000+.

The reason the SOH impact is smaller than drivers expect is that the licensed-trade buyer network we sell into prices the vehicle on its remaining plate-validity life and operational fitness, both of which are largely independent of SOH within the 78 to 95 per cent band. A cab with 9 years of plate life remaining at 82 per cent SOH is a more valuable working asset than a cab with 4 years of plate life remaining at 90 per cent SOH, because the trade buyer is going to run the cab for those remaining years.

Below 78 per cent SOH the maths changes more sharply. The cab is heading into either a pack refurb (£8,000 to £12,000 at LEVC, £5,500 to £8,000 at a third-party specialist) or accepting that the range-extender will do most of the work for the remaining plate life, which has fuel-cost implications the buyer factors in.

Refurbishing the pack before sale is almost never the right call for the seller. A £6,000 third-party refurb typically uplifts resale value by £2,500 to £3,500; the gap is the buyer's risk-and-return on the refurbished pack (refurbs from specialists vary in quality and the buyer is pricing that uncertainty). Selling with an honest SOH reading and letting the buyer factor refurb cost into the offer is usually £2,000 to £3,500 better for the seller than refurbing first.

Refurbishment makes sense if you are keeping the cab and planning to run it for another 3+ years of remaining plate life. The economics of the refurb cost are amortised over the additional running period, and the operational benefit (back to near-original range, reduced range-extender cycling, lower fuel consumption) compounds. The refurb-then-sell route does not work; the refurb-then-keep route can.

Put the variables together in this order:

• Get a current SOH + cell-balance report (LEVC dealer or qualified specialist).
• Compare against your SOH reading from 12 months ago, if you have one. If the drop is more than 4 percentage points, the pack is in accelerated phase and selling within 6 months is the prudent call.
• Check remaining plate validity. Less than 24 months and the resale curve is already steepening regardless of battery; selling now captures more value than waiting.
• Get a current trade valuation. Honest specialist buyer prices in your specific SOH and plate-time; the number gives you a real comparison against the cost of continuing to run the cab.
• Run the cab's forward maths: expected operating cost over the next 12 months (including any battery-related work the SOH trend predicts), expected income net of the operating cost, expected resale value at the end of that period given expected SOH drift and plate-time decay. If the forward net is below the current trade valuation, sell now.