BATTERY LIFE
Customers often ask how we know that the battery life of Holosun sights is so long when they have only been on the market for a few years. It comes down to simple math.
Any battery or more properly referred to as a cell in this case, has a capacity. The capacity is measured in ampere-hours or Ah. As an example, a AA size cell has a capacity of 2 to 3 ampere-hours. This means that the cell can supply a current of 2 - 3 Amps for 1 hour.
A CR2032 Lithium cell, has an ideal capacity of 250 milli-ampere-hour (mAh). A good quality CR2032 has a capacity 220 – 240 mAh. The Energizer CR2032 cell supplied by Holosun.ca with all Holosun sights distributed by Holosun.ca in Canada, has a capacity of 240 mAh.
As an example, an HS403A sight operating at intensity level 7 uses 5.9 micro-amps (µA). Using a 240 mAh cell, the battery life would be 40,600 hours. (240 mAh / 0.0059 mA = 40,600 hours). This assume continuous operation. Many of the sights have an auto-off mode that effectively extends this life to the shelf life of the cell.
Holosun.ca has set up test equipment to confirm the factory specifications.
The test equipment includes:
- And Extech MN16A digital multi-meter with a micro-ampere range,
- A custom built battery holder for a CR2032 with binding terminals,
- A CR2032 cell with the electrolyte removed and test leads attached that can be inserted where the battery tray goes,
- and a variety of cables and probes.
HS403C at intesity level 6, showing a current draw of 5.4 µA.
Here is a table of actual readings from a selection of sights. Please note that the accuracy of the meter is +/- 1.5% and that the length of the tes leads likely add to the current draw. This is far from laboratory quality.
The solar mode tests were performed with a bright fluorescent lamp indoors.
A few calculation examples:
HS503C on battery with the circle dot reticle enabled. Intensity level 7. 240 / 0.0242 = 9,917 hours.
HS503C on battery with dot reticle. Intensity level 7. 240 / 0.0156 = 15,384 hours.
HS503C on battery with circle dot reticle enabled. Intensity level 12. We call this thermonuclear. You can see this in the sun. 240 / 2 = 120 hours
HS503C on solar with circle dot reticle. Intensity level 7. 240 / 0.009 = 26,666 hours.
Intensity level 7 is actually quite bright. Indoor shooting would be at an even lower setting. As you can see, the battery life at a mid-level setting is years. This is further enhanced by auto-shutoff settings. By the nature of the electronics, as intensity increases, current draw increases more rapidly. Even at higher intensity settings, battery life still exceeds the competition.