When an e-bike that used to cover 60 kilometres without effort starts running out after 25 or 30, the concern is justified. On a lithium-ion battery, lost range can be temporary — down to external conditions — or the sign of irreversible cell degradation.
Here is how to tell a seasonal drop from genuine wear, why capacity sometimes falls in steps, and at what point reconditioning becomes more sensible than buying new.
Sudden or gradual loss: telling them apart
Before concluding that the pack is worn, look at how the drop arrived: all at once, or over several months.
1. Cold and riding conditions (temporary loss)
If range collapsed in winter or late autumn, the problem may not be wear but the physics of lithium.
The NORDIX experience
Our engineering work on Arctic batteries, designed to operate down to −70 °C, is unambiguous: as soon as the cells drop below +5 °C, both the capacity actually delivered and the available current fall. Depending on the chemistry, the loss can reach 40 to 60 %. A battery pre-warmed at room temperature does not have this problem: while riding, the cells' own self-heating is usually enough to hold a working temperature. The owner, however, generally has no way of knowing the real temperature inside the pack.
2. Chemical ageing (permanent loss)
Lithium-ion cells lose capacity as they age, even when little used. Every full cycle removes a little active lithium. A gradual loss of 10 to 15 % after two or three years of regular use remains normal.
3. Cell imbalance and cutting out on climbs
One scenario comes up again and again: the gauge still shows 40 or 50 %, but the bike — or the scooter — shuts down abruptly on a climb or at the first hard acceleration.
This is voltage sag under load. It depends directly on the pack's internal resistance, and it does not only affect worn batteries: you also meet it on new packs that were poorly designed.
The NORDIX experience
Cutting out on a climb through collapsing voltage is typical of low-cost solutions and of many scooters (Urban Glide, Kugoo/Kukirin and equivalents). In those packs the cells have high internal resistance from the outset. Under load the voltage collapses instantly and the BMS does its job: it cuts. No software setting and no repair will fix that — only reconditioning with genuine high-discharge cells solves it.
4. Mechanical drag on the bike
Do not overlook the mechanics: under-inflated tyres, rubbing brake pads, a worn chain or a strong headwind can eat 30 to 40 % of your range. Check tyre pressure and that the wheels spin freely before taking the battery to a workshop.
When should you consider reconditioning?
Common practice is to wait until the battery holds no charge at all. From a technical and safety standpoint, the criteria are far stricter.
The NORDIX experience
In our workshop we apply industrial criteria: a battery is considered due for reconditioning as soon as its real capacity falls below 80 to 85 % of the value stated on the cells, or once the pack's internal resistance has risen 10 % above its original calculated value. Continuing to use it beyond that accelerates degradation and raises the risk of overheating.
The signs that should send the pack for diagnosis:
- the bike no longer covers your usual daily route;
- the battery charges suspiciously fast and empties just as fast — the mark of internal resistance that has jumped;
- cutting out under load becomes systematic around 30 to 40 % on the gauge.
What reconditioning actually is
Reconditioning is often confused with a superficial repair or with buying a cheap copy. It is in fact the replacement of every cell inside your original case, with a new set of branded cells.
- The case and electronics are kept. We retain the case, the connectors and the original BMS board — critical on systems where the motor requires the battery to authenticate.
- New branded cells. The internal block is rebuilt entirely from fresh cells by recognised manufacturers.
- Often more range than before. Cell technology moves faster than bike model ranges. At the same physical size we can fit cells with higher energy density and raise the range appreciably.
- Traceability, not promises. The real danger with cheap packs is unknown cell origin and the absence of testing. Every battery reconditioned at NORDIX comes with the cell documentation — batch numbers, provenance — and an outgoing test report. You know your pack's real capacity, currents and protection thresholds.
The NORDIX experience
Two telling examples:
- Kalkhoff 12 Ah → 17 Ah: the original pack, reconditioned with current cells, gains around 40 % capacity in the same case.
- Entry-level packs: original batteries built on anonymous 2,500 mAh cells, reconditioned with Samsung 3,500 mAh, gain 40 % capacity immediately — and the cut-outs on climbs disappear.
See also our capacity increase service, which addresses exactly this gain at constant case size.
Range dropping? Have your pack tested near you
Do not wait for the breakdown halfway through a journey. If you have noticed a clear drop in range, describe your situation: we will point you to the nearest partner workshop in Bourgogne-Franche-Comté.
The workshop receives your battery, and NORDIX engineers run a residual capacity test on the bench, with a report stating whether reconditioning is warranted.