Maximize Battery Life in Cellular Asset Trackers by Configuring Wake Modes

Operators want to use their expensive machines (loaders, sprayers, excavators, aircraft, etc.) as much as possible, because at the end of the day, business assets are more of an asset when they’re put to work. When a fleet is distributed over a large area, knowing where equipment is so it can be put to work can be a challenge.

Over the last decade, it has become common for larger or more expensive equipment to be delivered from the original equipment manufacturer (OEM) with a telematics standard. Sometimes it’s a simple position reporting modem, other times there’s a huge volume of operating detail being delivered to the cloud. In any event, it makes it much easier for operators to start tracking a fleet of assets when the equipment comes standard with tracking capability.

The challenge

There are still holes when trying to conduct an efficient operation with a full picture of the fleet. These holes exist because many fleets have equipment that did not come with factory telematics.

For example:

  • Tenders, dump trucks, and other Milk Run equipment that create the maximum productivity of a working asset also typically do not have stock telematics
  • Specialized equipment produced in lower volumes by smaller OEMs, and therefore not factory-equipped with tracking features
  • Towed equipment that is not electrified (e.g. trailers, carts, screens, mowers, balers, tedders, rakes, grinders, chippers, etc.) and as a result have no built-in tracking connectivity
  • Expensive attachments that are unpowered
  • Older equipment that is in good working order but was delivered before connectivity was standard among major OEMs

Considering these holes, you may only be able to track a portion of the fleet. Even if it’s 75%, it’s not good enough. A project can’t happen if only 75% of the equipment is at the site. That makes these holes important to fill, but it also has to be easy. Operators don’t have the time or the interest to assemble a pile of dissimilar aftermarket technology offerings into a fleet tracking solution — they have a business to run.

The good news

In a previous blog (Understanding 4G LTE Categories) we discussed new kinds of cellular technology that have emerged as a portion of 4G offerings. These technologies, specifically NB-IoT and M1, create opportunities for very rugged and affordable “slap and track” cellular asset trackers. These kinds of trackers can be attached to any piece of equipment, and by using their own battery they can report its location for years.

This can be an easy fix to the problem, but getting real satisfaction out of these solutions is all about managing the battery life of the unit. Why?

  • Many rugged asset trackers are made without replaceable batteries in order to achieve an IP67 or IP69K rating. Although these trackers are cheap, they need to be discarded when the battery is used up.
  • Trackers with replaceable batteries lose the “easy fix” appeal once you’re spending time tracking down machines to charge their units or replace batteries. The appeal of this solution is ruined if you can’t leave a machine alone for at least a season — ideally for the life of the machine.

So, how do you use “slap and track” solutions to the maximum benefit of your business? I know people hate this answer, but it depends. As you consider your equipment tracking goals, it’s important to understand battery life and wake modes.


Understanding battery life in cellular asset trackers

Battery life is fixed, meaning you start with a bucket of energy and that is all you get. Therefore, to achieve maximum customer value, the focus needs to be about extending the duration of time that a rugged asset tracker can be used.

To maximize that energy:

  • Devices need to be off as much as possible
  • When on, devices should sparingly use the components that use a lot of energy (e.g. cellular and GPS)

Device manufacturers have put a bunch of battery management tools into these devices, and the asset tracking ecosystem, to make tracking as easy as possible. It varies by manufacturer, but when a device is advertised to have a 5-year lifetime, that’s typically based on an expectation of a few thousand positional reports over its lifetime. That works out to 1-2 position reports per day for five years. So, while the device’s lifetime is marketed in the form of years, in reality the lifetime is based on the number of positional reports utilized.


Understanding how different wake mode configurations affect battery life

Making the most of the battery management tools should get careful consideration as you deploy trackers. We recommend consulting with your tracking services or hardware supplier to dial this in as early as possible. Devices can typically be configured to report in the following ways (organized from most power hungry to least power hungry):

Periodic continuous reporting

For trackers that are integrated into the machine and connected to vehicle power, this is an easy and inexpensive thing to do. However, most customers with battery powered trackers will not want to use this mode. Having the device report every minute, or even every hour, will consume a lot of battery life.

Wake and report on movement

Many asset tracking devices include an accelerometer. These are great because they use minimal energy and can be used to wake the device when it moves. This is helpful if you want to know when equipment is moving from site to site or when equipment has begun working, for example. Depending on the tracker’s capabilities, it might be possible to set the device to report on movement but then to “snooze” for a period of time (e.g. 4 hours). A word of caution, however: if you can’t snooze its reporting behavior, this feature could run through the battery life quickly.

Wake and report on rest

This is related to the movement feature, but it notices when the device stops moving for a period of time (typically configurable) and then reports the device position. It’s an inverted version of the previous feature with the same benefits and challenges.

Start of day / end of day position reporting

This feature is generally easy to configure, easy to implement, and very friendly for battery life. Simply pick a time of day and have the unit report its position at that time every day. This can give you an overview as to where the equipment was left at the end of the day, giving you an opportunity to dispatch resources effectively at the start of the following workday. When combined cleverly with some of the above features (e.g. report equipment position at 5:00 PM, then report on movement in the event someone moves it after hours), it can be used to give an effective and timely overview of fleet positions while using minimal battery.

Wake on demand

This easy to use feature is very powerful and enabled by the newest generation of cellular technologies. For those of you who want to push your glasses a bit higher on your nose and nerd out with us about how this feature works, we’ll dig deeper in a future blog. For this post, we’ll talk about the capability at a high level so you can understand how to exploit it.

Using a computer or mobile device, you ask the equipment to report its location. This feature sends a message over the cellular network, which is stored in a mailbox of sorts. The device periodically checks that mailbox, using very limited energy, to see if it needs to report in. If there’s a request waiting, it reports its location.

The beauty of this feature is that whenever you need to know the location of an asset, you can have the device report in at the push of a button. The report doesn’t come back in seconds, because typically the device is configured to “check the mailbox” at scheduled intervals in order to minimize energy use. However, even waiting a few minutes to get the devices’ location is MUCH faster than driving from site to site looking for it.

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David Batcheller – President & CBO


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