Lithium-ion Polymer (LiFePO4)
One of the most advanced battery technologies soon to be available, is the solid-state lithium-ion-polymer battery. Lithium-ion polymer batteries are prismatic, (rather than cylindrical) and demonstrate good power and range (up to 50km per charge for our 12Ah variants) with relatively affordable cost, thanks to the comparable ease of solid-state production and complete absence of liquid electrolyte.
However, from Autumn/Fall 2009 our all new S model range of electrically assisted bicycles will come with a new command module, squeezing 50% more range out of our Panasonic Lithium batteries, rendering the more expensive and yet unproven new Li-Pol technology on hold until further proof has been gathered that the new technology is indeed stable and reliable. The new Panasonic Lithium-ion batteries will now extend the useable range of all our bikes to between 50km - 55km per charge on full power and sheds more than 2kg in weight off the complete bike (compared to NiMh), whilst extending battery life by up to 100%.
Li-Pol technology,still demonstrates that the current (Amps) discharge rates of are not as high as our standard Panasonic Li-ion batteries and the 26V Li ion Polymers will have slightly less range and lower power than our brand new 37V Li-ion Panasonic batteries now fitted as standard on our new S models.
Features and benefits of Li-ion-Polymer (LiFePO4) technology
- High energy density - Higher capacity/lower weight (delivering up to twice the capacity for almost half the weight of comparable NiMh Cells and power packs)
- Flat discharge profile - Superior motor performance
- High nominal Voltage (3.6V versus 1.2V for a typical NiMh cell) - Smaller package for same Ah rating
- Low self-discharge rate o Longer working time o Longer storage time between charging
- Long cycle life (up to 1000 full recharge cycles) o High return on investment
- High standard of safety (capable of sustaining up to 10V overcharge) - Suitable for a large variety of safety critical applications
- No memory effect - Can be recharged at any time during the operational cycle
- No Leakage and no heavy metal o Low environmental impact
- Flexible form factor - Any reasonable shape or size can be produced (prismatic)
- Very safe with no explosion danger - Suitable for a wide variety of safety critical applications
Urban Mover™ - Battery Comparison Chart
| Lead Acid | Silicon | Ni-Cad | NiMh | Li-ion | Li-Pol | Li-Pho | |
| Safety | Good | Excellent | Good | Good | Excellent | Good | Superb |
| Nominal voltage | 2 | 2 | 1.2 | 1.2 | 3.4 | 3.6 | 3.2 |
| Wh/Kg Energy density (gravimetric) | 35 | 50 | 41 | 80 | 120 | 160 -180 | 110 |
| Volumetric energy density | 80 | 130 | 120 | 200 | 280 | >320 | >240 |
| Cycle life | 200 | 400 | 250 | 400-500 | 400-500 | >1000 | >2000 |
| Memory effect | No | No | Yes | No | No | No | No |
| Operational temperature (C) | -15° to +50° | -50° to +70° | -20° to +50° | -20° to +60° | -20° to +60° | -20° to +60° | -25° to +60° |
| Flexible form factor | No | No | Yes | No | No | Yes | Yes |
| Self discharge (% per month) | <0 | <0 | <10 | <20 | <5 | <5 | <5 |
| Environmental impact | High | Low | High | Medium | Mid-Low | Low | Low |
| Initial purchase cost | Low | Medium | Medium | Medium | Mid-High | High | High |
| Lifetime cost (based on range and cycle life) | High | Medium | Medium | Medium | Low | Very Low | Very Low |