The A123 battery alternative for quick scrambles to the slope

An interesting copy off SARFLY from a useful post by Christo. A (large) battery that can be charged in a quarter of the time must be useful to after work slope flyers..... ;-)


----- Original Message -----
From: DavidT
To: lrk-torquemax@yahoogroups.com
Sent: Sunday, May 06, 2007 8:09 PM
Subject: [lrk] A123 cells

I will only buy A123's now for large models. I'm fed up with how sensitive Lipos are. A small mistake can cost a great deal on large packs especially if you buy expensive ones. A123's take the best of both Nicads and Lipos. I have a writeup of the differences here:

http://www.flyelectric.ukgateway.net/lithium-a123.htm

You can upgrade your Schulze to charge them. If you don't upgrade then some lipo settings are a close match (with a different cell count).

If you have a 'balancer' type of balancer (as distinct from the 'charge guard' type) then it should handle A123s.

You need to think about in flight low voltage cutoff. You can get some ESCs to do what you need. I am designing some PIC-based circuits at the moment that will monitor individual cells (any chemistry and much less important with A123's). This will be an add-on to existing ESC's.
I'm testing a 3 cell version and it will be easy to handle any number of cells once the software is OK.
www.flyelectric.ukgateway.net/pic-lvc1.htm

http://www.a123systems.com/newsite/index.php#/home/