Users often ask how long batteries will last in a certain type of use case. This article describes the usual battery life expectancy for different bttn models and the different factors that will shorten the expected battery life.
General - read this first:
- bttn has a built-in power save mode that is used whenever bttn is run on batteries. bttn goes to sleep after each press, and wakes up again when pressed. In power save mode the power consumption is negligible. If your bttn Classic is never pressed, high quality alkaline and lithium AA batteries will last for 3-5 years ("stand-by time").
- bttn uses the most power when transmitting. The more often the bttn is transmitting, the faster the batteries will go out. We therefore state the battery life expectancy in number of presses, not in days. I.e. your battery life depends greatly on how often your bttn is pressed.
--- For example, a mobile data bttn typically performs up to 1000 presses with alkaline AA batteries. If the bttn is pressed 3 times per day, it will run for nearly a year with one set of batteries.
- Actions that take a long time to finish (e.g. a HTTP with a callback that comes after 30 seconds or SMS with response) require bttn to poll the action's status from server several times (several transmissions). Such actions thus consume more power than those actions that require only one transmission and finish right away (e.g. email or press counter).
- bttn has a built-in heartbeat feature (the feature can be enabled under bttn properties), that allows users to know that their bttns are operational even when they are not being pressed. A heartbeat requires bttn to transmit, and therefore heartbeat messages can be counted as a bttn presses when forecasting battery life.
- Battery and signal level data is sent to server with each event (boot, press and heartbeat), so the battery and signal level indicators in my.bt.tn are based on the last known event.
- bt.tn server sends automatic alerts of poor signal and low batteries to account holder's email address and to "email address" field specified under bttn properties. The bt.tn REST API interface also allows you to periodically query the battery and signal levels to your own system (a reasonable interval is once per day or once per week).
Classic mobile data bttn:
- In good signal conditions with high quality alkaline AA batteries (e.g. Duracell Ultra Power) the bttn can perform up to 1000 presses.
- In good signal conditions with high quality lithium AA batteries (e.g. Energizer Ultimate Lithium) can perform up to 2700 presses.
- The bttn Mini mobile data has a shorter stand-by time than the classic bttn, typically from 6 months to 12 months.
- Battery life will be shorter if signal is poor, because transmitter has to use higher power and stay on for longer times because of retries. If signal is very poor, bttn may occasionally not connect at all, and then constant retries may empty the batteries rather quickly.
- With a roaming SIM card, waking up from sleep and establishing connection usually takes slightly longer than with a local SIM card. Therefore the battery life may be shorter with a roaming SIM card than with a local SIM card.
- bttn device itself shows current signal level when started in mobile data setup mode. Make use of this when selecting the install location.
Mobile data bttn Mini:
- bttn Mini has a slightly different power-save mode: When given a full charge, the Mini will stay active until battery level goes down to 70-80%. This allows you to control the speed of operation: if you need a fast bttn Mini that doesn't go to sleep, you can recharge it before use or e.g. every night.
- The Mini has an internal, rechargeable Li-Po battery (3,7 V / 1800 mAh).
- In good signal conditions, with a fully charged battery, the bttn Mini can perform up to 1000 presses.
- Battery life will be shorter if signal is poor, because transmitter has to use higher power and stay on for longer times because of retries. If signal is very poor, bttn Mini may occasionally not connect at all, and then constant retries may empty the batteries rather quickly.
- With a roaming SIM card, waking up from sleep and establishing connection usually takes slightly longer than with a local SIM card. Therefore the battery life may be shorter with a roaming SIM card than with a local SIM card.
- bttn Mini device itself shows current signal level when started in mobile data setup mode. Make use of this when selecting the install location.
Classic Wi-Fi bttn:
- In good signal conditions with high quality alkaline AA batteries (e.g. Duracell Ultra Power) the bttn can perform up to 1000 presses.
- In good signal conditions with high quality lithium AA batteries (e.g. Energizer Ultimate Lithium) can perform up to 5000 presses.
- Battery life will be shorter if signal is poor, because transmitter has to use higher power and stay on for longer times because of retries. If signal is very poor, bttn may occasionally not connect at all, and then constant retries may empty the batteries rather quickly.
Classic SIGFOX bttn:
- Estimated battery life up to 3000 - 5000 presses with high quality alkaline AA batteries (e.g. Duracell Ultra Power). Estimate is based on lab tests and actual field performance may be vary. Power consumption is much less than that of 2G and Wi-Fi.
- Battery life has not been tested with Lithium AA batteries but it is expected to be significantly higher than with alkaline.
The above battery life figures are general estimations based on statistics. The performance may be different in your use case and location. All data in this article is subject to change without notice.