Sunday, February 10, 2013

Battery Holders, Chargers, home brew gizmos.

Commercial Protected battery holder

The one thing that I thought I needed is a protected battery holder, since the batteries have  no protection circuit built in.  Plus some sort of keyed connector - when I got these on eBay, they came with the JST connectors sets - maybe it was a mistake since the listing doesn't mention it in the listing, but a welcome surprise.

Firecracker Battery holder


My first take at a battery holder. Kind of looks like a firecracker, doesn't it? Just took the battery and wandered around the local home supply store and tried different things. I love PVC, I found these gizmos that press fit onto the battery.  I scavenged some springs from an AA battery holder - drilled a hole in the end and ran the wire through.  Voila - dangerous, but serviceable. Made sure that it had all kinds of markings identifying which end is which. This plus a protector board, a JST connector will find its way outside to the weather transmitter.



The KahnFire Charger setup


The protection board in the circuit



And the charger


Added a trimmer to dial in the current for different batteries.  It's almost set to a short to get the 800 ma to charge the 18650s



2 comments:

bogdan craciun said...

Hi there!

I saw your post (both on your blog and Cosm forum) regarding some tests on routing a nRF24L01 wireless network to Cosm, and having problems with those 2 libraries (rf24 and Ethernet) to work togheter.
Did you get any result?
I would appreciate if you could share your knowledge.

I am trying to make a similar configuration, but I was thinking maybe using an nrf24 shield connected to a RasperryPi acting as a base station for all the arduino motes, and sending data to Cosm.

Regards,
Bogdan

Syd Kahn said...

Well I am having two solutions. Jee Labs has the solution to the problem. He uses the rfm12b module on all his JeeNodes, and there s quite a code base. Could even use ATtiny85 with them. I have two radio modules but haven't gotten around to experimenting with them yet.

My best solution if I want to keep the existing setup, is to use a Raspberry PI. That is a little learning curve because of Linux, but it is by far the cheapest. That is f one could find one in stock anywhere.