Memory & Power - Alternatives

Hi Everyone,

I have a few questions relating to Memory & Power (Video 1.2b).

I wondered if there was any reason for using AA batteries as opposed to a LiPo?

I’d be interested to learn more about using ‘alternative’ energy sources to recharge batteries in-situ (Solar, Wind, Kinetic – Animal Movement, & more ‘exotic’ Hydrogen/ salt-water fuel cell system sources).  Has anybody had experience with any of these?

In smaller applications, something like these ‘Moovement’ GPS Ear Tags, they have a battery and integrated solar panels.  See: https://www.moovement.com.au/wildlife-tracking

As well as if anyone has had experience with Microbial Fuel Cells (MFC) on land or with gaining energy from sea-bed sediments in-situ?  For example, see; ‘Microbial Fuel Cell (MFC) as a Sustainable Land Monitoring Energy System’;

https://www.researchgate.net/publication/277673916_Wireless_Sensor_Network_Powered_by_a_Terrestrial_Microbial_Fuel_Cell_as_a_Sustainable_Land_Monitoring_Energy_System

Many thanks

Rob




Hi Rob

Really good points, and yes, renewable power sources, esp. solar, are often used. 

For those who may not know, LiPo refers to Lithium Polymer batteries, a type of rechargeable battery. We tend to use rechargeable Lithium Ion because they're cheaper and have a higher power density. 

We chose AA batteries as a starter to maximise the places the data logger can be deployed (caves, permanent shade etc), and to reduce the risk of it failing in the field due to power consumption versus recharge rate. 

Also everyone's familiar with AA batteries, they can be sourced very easily (esp. in remote and rural places), and we can't ship batteries.

Having said that, we do use solar on devices but it's dependent on the application, deployment conditions and maintenance requirements. 

When deciding AA batteries versus solar, we'll do a sun / weather audit of the deployment conditions, look at the power consumption based on when the device is active (and how often it’s taking readings), how much recharge we anticipate it will need, whether it can be mounted securely (solar panels get stolen in some areas we work), and whether mud or other debris getting on the solar panel and reducing / stopping the recharge, will be a show stopper. 

Solar needs a different power circuitry on the board. 

Hope that answers your question.

There's definitely some interesting renewable options and something to keep exploring, so we're also keen to hear others' experiences.

cheers

Jacinta

 

Like Jacinta mentioned, there are a few considerations. Another one is whether it's safe to have cables coming out of the board for detached external solar panels. There's something about cables that seems to invite monkeys to pull on them and animals to chew on them. 

That said, we do like solar and will be covering that later on in the course modules along with different types of batteries. There are different things to consider such as fixed current charging or Max Power Point (MPPT, not Microsoft - ha ha ha) and also pairing it with different types of batteries. It's a fascinating topic and whenever we can, we prefer reusable batteries than disposable.

Akiba

Hi Guys,

Many thanks for the replies & glad to hear that we’ll be touching on the subject a little more in the course.  I’ve been watching a few ‘maker’ videos online & appreciate the challenges.  But ‘energy harvesting’ is something that really interests me.  Prior to Covid, I was based at an ‘Eco’ Resort in Panama, where hopefully I’ll return to in the near future (https://islassecas.com/).  We do have solar for the resort infrastructure.  (See: (https://www.youtube.com/watch?v=Ww-_PU6cVz0).  I appreciate what you said about the solar panels efficiency and being covered in mud/debris.  I was flying a drone with a thermal camera, to test for such impairment on these panels.

Made me smile about what you said about getting cables chewed by the wildlife – I’ve certainly experienced that.

Cheers