Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: totalis on September 25, 2010, 04:31:27 PM

Title: Li-ion DIY?
Post by: totalis on September 25, 2010, 04:31:27 PM

Hi all,

after over a year and £500 pounds spent on robotics (which is a lot of money and effort when doing a physics degree aswell) i have come to the conclusion that conventional Ni-Mh batteries are not a perfect solution, with a 1hr usage time and a 24hr recharge time, they leave a lot to be desired. I happen to have worked at a computer centre over the summer. i have obtained ~30 Li-ion cells from spare battery packs.

My question: has anyone on here ever build their own battery pack from li-ion cells and made a suitable charger for them?

if so, do share.

i will share my results soon :)

T

Title: Re: Li-ion DIY?
Post by: madsci1016 on September 25, 2010, 05:00:37 PM

I wrote this for a long distance friend a while ago.

http://www.billporter.info/?p=154 (http://www.billporter.info/?p=154)

Didn't build my own charger, but bought a commercial charger for $20 something.

Title: Re: Li-ion DIY?
Post by: billhowl on September 25, 2010, 09:34:05 PM

This article discusses LiIon batteries and describes a universal Lithium Ion battery charger with a Smart Battery interface based on an Atmel ATMEGA8 microcontroller using GCC ver. 3.2
http://www.seattlerobotics.org/encoder/200210/lithiumion.htm (http://www.seattlerobotics.org/encoder/200210/lithiumion.htm)

Title: Re: Li-ion DIY?
Post by: codiak on September 27, 2010, 10:20:12 AM

The batteries you yanked are 18650's Li-On's and most of the older models are unprotected wrt to over/under charge on their own.
You can find many discussions for safe wiring/charging at www.Candlepowerforums.com (http://www.Candlepowerforums.com)

Title: Re: Li-ion DIY?
Post by: madsci1016 on September 27, 2010, 11:30:20 AM

Quote from: codiak on September 27, 2010, 10:20:12 AM

The batteries you yanked are 18650's Li-On's

I'm aware.

Quote

and most of the older models are unprotected wrt to over/under charge on their own.

If you read my tutorial, you will see the PCB I attached to them protects the cells and balances charge across them.

Title: Re: Li-ion DIY?
Post by: Asellith on September 27, 2010, 12:14:15 PM

Hack-a-day got your tutorial Bill :) Hope you hostings good.

http://hackaday.com/2010/09/27/making-your-own-lithium-ion-batteries/ (http://hackaday.com/2010/09/27/making-your-own-lithium-ion-batteries/)

Title: Re: Li-ion DIY?
Post by: madsci1016 on September 27, 2010, 12:47:47 PM

Quote from: Asellith on September 27, 2010, 12:14:15 PM

Hack-a-day got your tutorial Bill :) Hope you hostings good.

Yeah I saw! I use 1&1, the largest hosting firm in the world, and it survived the last two hack-a-day attacks, so it should be fine.