Ownership cost is a timeline, not a showroom price. VRLA, NMC and LFP can all be sensible in the right vehicle. The correct comparison adds purchase price, charger, energy, service, battery replacement, downtime and resale over the same distance.
Use a scenario table
| Battery | Typical advantage | Cost risk |
|---|---|---|
| VRLA | Lower entry cost and familiar service | Weight, voltage sag and earlier replacement under deep cycling |
| NMC | High energy density and low pack mass | Higher pack price, thermal-management and BMS quality |
| LFP | Long cycle tolerance and strong thermal stability | More mass than NMC and still dependent on BMS and cells |
Illustrative five-year model
For a fair example, assume 12,000 km/year, 60 km nominal daily use, one complete pack sized around 2 kWh and the same scooter. These numbers are intentionally generic: real pack prices and life must come from a written quote.
| Cost over time | VRLA | NMC | LFP |
|---|---|---|---|
| Year 0 pack and charger | ৳45,000 | ৳105,000 | ৳125,000 |
| 2-year likely reserve | ৳45,000 replacement risk | ৳0–105,000 depending on warranty | ৳0–125,000 depending on warranty |
| 3-year likely reserve | Second replacement may be possible under hard use | Capacity check and service | Capacity check and service |
| 5-year planning reserve | Highest uncertainty | Moderate uncertainty | Lowest uncertainty if pack is genuine |
The table is a planning model, not a price list. Its lesson is that the chemistry with the lowest purchase price can have the highest delivered-kilometre cost if replacement happens early. Conversely, an expensive lithium pack is poor value if it has no traceable cells, weak BMS, no repair route or an invalid warranty.
Calculate 2, 3 and 5 years
- Two years: compare purchase premium, electricity and routine service. Do not assume a replacement unless the warranty and duty cycle support it.
- Three years: add the probability-weighted replacement cost. A 30% chance of a ৳100,000 pack event is a ৳30,000 reserve.
- Five years: include at least one realistic battery event, resale, downtime and the possibility of a second-hand vehicle with a tired pack.
Cost per kilometre = (purchase + energy + service + replacements + downtime − resale) ÷ lifetime kilometres. Use conservative and optimistic columns, not one false-precision number.
What to request from a seller
Ask for the pack’s nominal and usable Wh, test depth of discharge, cycle-life end point, BMS current rating, charger model, warranty exclusions, replacement price and expected lead time. For VRLA, ask for matched battery manufacture dates and a capacity test. For NMC or LFP, ask for cell supplier, configuration, BMS protections and safe repair policy.
Verdict
VRLA can win at low annual mileage and low entry budget. NMC can win when weight and compactness matter. LFP often offers the most forgiving long-term ownership profile for frequent cycling. The winner is the complete system with the clearest evidence and support.