I purchased a set of LiFepo4 batteries from Headway Battery in China. http://www.headway-cn.com/
I have 512 of the the 38120-S cells. These are 10Ahr cells with an operating Voltage of 2.5V-3.65V
Dimensions 38 (mm) x146 (mm), Weight 307g Max continuous discharge 5C Max pulse discharge 15C
At my request they were arranged into 16, 32 cell packs configured as 8P4S. Each pack is should deliver 10V-14.6V at 80 Ahr.
The issue I’m having is RUST. About half the cells have formed some serious rust on the positive cell terminals. I’ve discussed this issue with Headway and they claim the batteries were stored incorrectly. This is not the case. The long term storage specification for the batteries is 35 degrees C, which was not exceeded.
The packs were delivered in July 2009 and have been stored in my garage here in South Florida since. They were stored on a metal cart about 10″ off the ground inside the garage. The location is an non-air conditioned attached garage. It sure can get humid here in South Florida but the packs were never exposed directly to water.
Here are some pictures taken a few weeks ago.
This is a WPSimpleViewerGallery
office stationery…
I wish I had read this article last month, it would have made my job easier…