Real-World Performance Across 250W–1000W Motors
Choosing the right lithium cell for an e-bike battery is not just about nominal capacity (mAh).
In real riding, current draw, voltage stability, heat generation, and cycle life matter just as much — often more.
This article compares Samsung INR21700-50G and LG INR21700-M50T from a practical, engineering perspective, focusing on how they behave in 250W, 500W, 750W, and 1000W e-bike applications.
1. Cell Overview (At a Glance)
| Parameter | Samsung 50G | LG M50T |
|---|---|---|
| Format | 21700 | 21700 |
| Nominal Capacity | ~5000 mAh | ~5000 mAh |
| Nominal Voltage | 3.63 V | 3.63 V |
| Typical Continuous Discharge | ~9–10 A | ~7–10 A (application dependent) |
| Design Focus | Power stability + durability | High energy at low current |
Important:
Both cells are high-energy NMC cells. Neither is designed as a pure high-power cell — differences appear mainly under load.
2. Why “Wh on Paper” ≠ “Performance on the Road”
Many customers notice this phenomenon:
At low discharge current, LG M50T packs sometimes deliver higher measured Wh than Samsung 50G.
This is real, and the reason lies in the voltage curve, not in fake capacity.
3. Conceptual Voltage Curve Comparison (Low Current)
Test condition (example):
- Constant current: ~7A (pack level)
- Same BMS cut-off voltage
- Same pack configuration
What this shows:
- LG M50T maintains a slightly higher average voltage during low-current discharge
- Samsung 50G voltage curve is more conservative
➡️ Result:
At low current, LG M50T can output more Wh in lab tests, even if mAh difference is small.
4. Voltage Sag Under Load (Conceptual)
Now let’s look at higher current, closer to real riding.
Higher current = stronger internal resistance effects
Key observations:
- Samsung 50G
- Lower voltage sag
- Better stability during acceleration and climbing
- LG M50T
- Voltage drops faster under higher load
- Earlier BMS cut-off under real riding conditions
➡️ This is why “paper Wh” does not equal “real riding range”.
5. Matching Cells to Motor Power (Practical Guide)
🔹 250W E-Bike (EU-style commuting)
- Typical pack current: 5–8A
- Per-cell current (13S3P): ~1.7–2.7A
Best choice: ✅ LG M50T
Why:
- Optimized for low current
- Higher average voltage
- Excellent for flat terrain and range-focused riding
🔹 500W E-Bike (Urban + light hills)
- Typical pack current: 8–18A
- Per-cell current: ~2.7–6A
Best choice: ✅ Samsung 50G
Why:
- Better voltage stability
- Stronger acceleration
- Less heat buildup over time
🔹 750W E-Bike (Hilly terrain, cargo, heavier riders)
- Typical pack current: 15–25A
- Per-cell current: ~5–8A
Best choice: 🔥 Samsung 50G
Why:
- Designed to tolerate sustained load better
- Less voltage sag on climbs
- More consistent power delivery
🔹 1000W E-Bike (High stress use)
- Typical pack current: 20–30A
- Per-cell current: ~6.7–10A
Recommendation:
- Samsung 50G is preferable
- Or consider more power-oriented cells if thermal margin is limited
⚠️ At this level, both cells are approaching their comfort limits.
6. Cycle Life & Durability (Realistic Expectations)
Conceptual Trend
Interpretation:
- Samsung 50G
- Better resistance to degradation under higher load
- More suitable for demanding daily use
- LG M50T
- Performs well when kept at low current
- Faster aging if frequently pushed hard
7. Why Cut-Off Voltage Matters
Customers often assume:
“Higher cut-off voltage = less Wh”
This is correct, but only part of the story.
- Higher cut-off → protects cells → longer life
- Lower cut-off → extracts more Wh → but from a low-voltage region where:
- Voltage collapses faster
- Motor efficiency is lower
- Stress on cells increases
This is why extra Wh gained below ~3.0V per cell often has little real riding value.
8 Honest Summary
LG M50T
Best for low-power e-bikes where range and efficiency at low current matter most.
Samsung 50G
Better for real riding performance — hills, acceleration, durability, and long-term reliability.
There is no “better cell”, only a better match.
9. Final Recommendation to Customers (Sales-Safe Wording)
If your priority is paper Wh measured at low current, LG M50T may show slightly higher results.
If your priority is real riding performance, voltage stability, and long-term durability, Samsung 50G is the more robust choice.
