Rechargeable energy sources
Ni-MH rechargeable batteries have become common. They are easily found in LR06/AA and LR03/AAA formats. They have the advantage of being rechargeable and able to power other household items (remotes, cameras...).
- Strong points: availability, rechargeable.
- Weak points: price, memory effect (premature wear when the batteries are not discharged and charged correctly), lower performance than Li-Ion.
Petzl lamps that work with standard batteries are supplied with alkaline batteries. Most of these models are compatible with Lithium-Ion and Ni-MH batteries.
An interesting fact to note is that these two battery technologies have a positive effect with lamps that use CONSTANT LIGHTING technology. In effect, using Lithium-Ion or Ni-MH batteries can double the burn times in all modes without impacting brightness!
Lithium-Ion rechargeable battery technology now offers the highest performance for your Petzl rechargeable headlamps. More expensive, but also lighter, these batteries are found in all common high tech devices, such as cell phones or MP3 players.
Operation of Lithium-Ion batteries.
Lithium-Ion batteries require a specific charging device.
Charging times and cycles
Most Lithium-Ion batteries use a rapid charge to recharge the device to 80% capacity, then switch to slow charge to reach 100% capacity.
Li-Ion batteries have a large number of charging cycles. One charging cycle corresponds to usage, then recharging the battery to 100% of its capacity.
However, after a certain number of charging cycles the Li-Ion battery loses capacity. For example, the TIKKA RXP battery retains only 70% of its initial capacity after 300 charging cycles. A battery inevitably loses its capacity over time, whether it is used or not.
Advantages of Lithium-Ion batteries
Lithium-Ion batteries have a high energy density and can thus deliver three times the voltage of Nickel batteries. With equal power, a Lithium Ion battery weighs up to 60 % less than a nickel battery. Overall, you get better performance at reduced weight.
- No memory effect
Lithium-Ion batteries are not susceptible to it. Therefore, no charging precautions are required. You can charge your battery whenever it is convenient, without having to wait to completely deplete or completely recharge the battery.
- Low self-discharge and the effects of storage on battery capacity
Lithium batteries are only slightly susceptible to self-discharge. A battery of this type loses about 5% of its capacity the first day, then about 10% per month after that.
- Low effect of extreme temperatures on batteries in use
One of the big advantages of Lithium-Ion technology is that it performs well in extreme temperatures. In use at -20° C, a Lithium Ion Polymer battery loses an average of 35 % of its initial capacity, while a nickel battery loses 80 %.
Petzl offers several charger models for its various headlamps. For applications where electrical outlets may be unavailable for several consecutive days (long journey, ski touring, mountaineering over several days ...), the USB-rechargeable lamps are very practical because of their compatibility with many universal systems. One can use a standard charger, but also a solar charger or even a portable power supply...