Need suggestions on battery

As my sensor will be located in a hard-to-reach location, it is crucial that it can be powered for as long as possible with a battery (no recharging). The average current draw of the sensor is in the range of 200 to 400µA, though sometimes with peaks at around 200mA. Currently I use a 3.7V 2A LiPo battery, but after some calculations the lifespan at best is only around 7 months or so. I need something that can charge it for way longer than this, preferably in the range of 2-3 years minimum.

I don’t have a background in electronics so I’m largely uneducated when it comes to specifications. Would you guys recommended a larger-sized LiPo battery (e.g. 6A, 8A) or a different type of battery? It doesn’t need to be rechargeable; temperatures can get to minus 20 Celsius in the winter, up to plus 50 degrees in the summer. Size dimensions are not an issue. Voltage input of the sensor board should be around 3.7V. Price per battery should preferably be less than about $15.

Have you considered that your problem might be solved by reducing the amount of power consumed by the ‘sensor’ ?

If you want a battery lifespan that measures in years then you will need to take account of the self-discharge of the different battery technologies.

For reducing the energy needed by your project have a look at Nick Gammon's low power tutorial.


Have a look to see if you can turn off the sensor and only turn it on when you need a read. If the remote sensor has an Arduino associated with it , then google putting the Arduino to sleep. A small solar panel may well give you a longer service tine

Self-discharge of the battery will be the driving factor. Most rechargeables won't have anything like full charge after 2-3 years if they're left on the shelf. You probably need to use non-rechargeable batteries.

Don't forget the common AA battery is so popular because it's actually a good battery. $15 of AA batteries is a pretty big battery pack.

LiPo cells seem to have a low self-discharge rate - though I have never tried to measure it.